# 7/8n2 4-4-0 Loco Project - Beira Rwy F4 / SAR NG6 / Lawley



## clifforddward (Jan 2, 2008)

This thread will track progress on my next 7/8n2 loco project, a 4-4-0 coal fired engine. A group of these engines were built in the 1890s for the Beira Rwy which was the first 2ft narrow gauge railway in Southern Africa. The story of this railway and the engines can be found on the internet...here is a good summary from Wikipedia:
http://en.wikipedia.org/wiki/South_African_Class_NG6_4-4-0
Originally classified by the Beira as "F4" engines, they were later renovated and classified by the South African Railway as "NG6" engines. Also commonly referred to as "Lawley" locomotives, a name referring to the primary builder of the Beira Railway.

I've been working closely with modeler Steve King on this project for the past several years. Steve and I have several long term joint projects ongoing...our approach to projects is similar, and we each have differing skills we bring to the build, not the least of which is cross checking each other during the research phase...we have found these collaborative efforts are very important. On scratch built projects where there are a thousand decisions (and mistakes!) to be made at every step, it is helpful to have others along for the ride to have someone to talk with. Several others have been in on this project from time to time...currently there are 4 (plus maybe one more) under construction, two of which I am building.

Here is an early photo of the prototype engine:









Several of these "Lawley" engines still exist in preservation...two are running at the Sandstone Heritage Trust in South Africa. This one is painted in the original Beira Rwy colors. While this is one of the earlier "F2" Beira engines, it included along with the F4 engines in the later SAR "NG6" classification (gets confusing, doesn't it?!):









Enough for background prototype information, this is a live steam modeling thread!...

For research and plans creation, we like to use works drawings when possible...in the case of the Lawley locomotives we were in luck:









In addition, there are drawings that others have done that can be used for general arrangement comparisons:









From these research drawings Steve utilized his side hobby and created working CAD drawings to 7/8" scale. 7/8" to the foot is our preferred scale for modeling 2' gauge prototypes...45mm gauge track works out perfectly to scale. Using CAD drawings made to actual scale model size it is possible to create files to do laser cuttings of the frame, bogie pieces and the like. Plus as I machine parts for the engine I can constantly refer back to the plans...pieces are made to fit.

For this engine, we are trying something new for us...water jet cut boiler pieces. Also we are incorporating tab and slot construction and butt joints rather than flanged components. On top of this, for our size boilers the latest general consensus among boiler makers is that a dry backhead can be used...this will make boiler construction MUCH easier than our last project.

Here is a photo of the water jet cut boiler parts (this photo is of the prototype copper set so is slightly different than the final set I'm using in the photos that follow....but does show the general appearance of water jet cut boiler parts for the project) :








May not look like much, but working from these water jet cut parts saves a HUGE amount of fabrication time. 

For those interested in making their own boiler, I encourage first buying Alec Farmer's 1988 classic book "Model Locomotive Boilermaking". The subject is a ride-on sized boiler, but the techniques are identical. I use about 85% of the actual steps he outlines in this book when making my boilers.

Since it is hard to silver solder and take photos at the same time (well, actually impossible!) I won't show every step of making the boiler...what I will do is provide some tips and techniques that I have discovered particularly helpful. First is one of the many jigs I find helpful during workshop time...this one is for holding the firetubes in place while silver soldering to the firebox front:








This photo actually shows tubes set up to be soldered for my K1 boiler (I forgot to photograph the Lawley set up), but the jig is the same and shows how it is used. As is so typical of many operations, making the jig took more time than using it to solder the tubes! Using jigs like this are very important as you need to be able to hold parts perfectly in alignment during the heating for silver soldering. It is impossible to free-hold parts, and with the higher heat involved, parts can easily move around with the expansion of metal as it heats up.

Here is a photo of the two Lawley boiler tube assemblies side by side after soldering:








As a further example of how I held components in place during silver soldering, look at this series of photos showing attachment of the firebox crown stays. 

First is the initial set up where I used stainless steel bolts, nuts, and washers through existing holes to locate the stays and keep them upright. It is also easy to see the "tab and slot" construction method being used on the Lawley boiler...the tabs help locate the parts and hold everything in place. I'm finding it makes the whole process faster:








You'll notice that the copper in the area to be joined has been thoroughly cleaned. This is VERY important in silver soldering. I would say the two areas most people struggle with initially when learning to silver solder copper is cleanliness of the components and lack of using a large enough torch...Copper conducts, pulls away from the joint, and dissipates heat very well...it takes a LOT of heat to keep everything up to temperature during the heat cycle. Firebrick pieces can do a lot to help isolate and insulate sections being heated, but there is no substitute for using a large enough torch. I have a variety of tips and find myself working up in size as more copper pieces are joined together and the boiler becomes a larger heat sink.

Below are the two assemblies in the hearth ready for heating. I made this silver soldering hearth from a junk gas grill and it was perhaps the best "wasted weekend" I've ever had...my propane tank and Sievert Torch are permanently mounted underneath and the firebricks are easily configurable. When not in use a standard grill cover hides everything and keeps the SWMBO happy. There is a great deal of heat volume involved in silver soldering larger assemblies like our locomotive boilers, and having the hearth helps contain the heat and make it easy to concentrate on the action at hand...no room for mistakes when a large gas flame is being danced around!:








Sorry, I was not able to show the silver soldering as it is being done...perhaps sometime I'll be able to have an assistant photograph things as the soldering is taking place...in the mean time it will be "before and after" photos. Here is a close-up image of the firebox stays cooling down...silver soldering has been completed, and there is a nice fillet of solder on both sides of the stays and also through the tab/slot arrangement...later inspection confirmed good penetration of solder through the slots into the top of the firebox so a water tight seal is assured. Also note the stainless steel bolts/nuts/washers have done their job holding everything in place. Stainless steel is a difficult to solder material requiring special flux...here we use it to advantage in holding parts since there is less likelihood of it getting caught up in the operation and becoming attached:








The "crusty film" seen in the photos is the cooled flux over top of the solder fillet and surrounding area...after cooling down the assembly goes into the Sparex pickle overnight, at which time the flux is gone and everything is clean, bright copper again.​


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## livesteam5629 (Jan 2, 2008)

Cliff and Steve
Where did miss the notice about the boiler cuts ? My chasis is sitting on the shelf waiting for a boiler and now you guys have two finished. Steve, drop me a pm on availability of boiler parts. Far too much has been happening to me since March. 
Noel
PS Looking good.


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## clifforddward (Jan 2, 2008)

Noel:
Steve is not on this forum so will not see your question....I suggest you write him directly...I'll send you a PM with his email.
This thread is for sharing project with others...let's keep internal build conversation to direct email exchange among the several project builders...heaven knows with all the back and forth that takes place relating to day-to-day build issues we'd quickly bog down this thread (and bore the rest of the group to tears!).
Best Regards,
Cliff


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## David Leech (Dec 9, 2008)

Cliff,
I notice in the photo of the two sets of boilers in the flue tube stage, that the tubes are sticking out into the firebox.
Do you trim the excess off?
I wonder if the hot gas flow works better if flush, or perhaps there is no difference.
Just curious.
All the best,
David Leech, Delta, Canada


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## clifforddward (Jan 2, 2008)

David:
I have not done experimentation, so cannot provide a comparison comment to answer your question. It would be easy enough to file down the ends of the tubes, but I will leave mine as is due to the following explanation.

Looking at photos in Farmer's book as well as other images in reference Model Engineer books from my library, there seems to be a small extension of the flue tubes into the firebox (maybe 1/16-1/8")...I assume to assure a good fillet of silver solder on both sides of the firebox tubesheet for a joint of maximum strength. I always use plenty of solder with a good fillet at tube/tubesheet junction for two reasons: 1) There is no way to get back at this spot for silver solder repair once the boiler is complete and in testing...a bad leak at this point is real trouble, and 2) when silver soldering the firebox wrapper there is a lot of heat close to the tubes...and a tendency for the tubes to get loose (silver solder beginning to soften at the tube/tubesheet joint)...for me having plenty of solder there keeps the joint from softening as quickly during the wrapper attachment. 

Besides, all of this is internal so the additional silver solder provides a measure of strength without any visual issues.

I'm also of the opinion that anything that increases turbulence in the firebox is a good thing rather than the draft going in a straight line...sort of along the lines of the firebox "shelf" that is often put in larger model locomotive boilers (ride on sized) ...but this is my opinion only and not backed up by testing.

Best Regards,
Cliff


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## BigRedOne (Dec 13, 2012)

That prototype is a cute little fellow!

I'll be following this thread with great interest, as I'm just now planning the boiler for my first steamer build.

Thanks for all the information you're giving us.


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## Kovacjr (Jan 2, 2008)

Looking good Cliff, makes me think I need to make a soldering setup with a grill. I have too much torch stuff in the garage.


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## clifforddward (Jan 2, 2008)

Best to make that silver soldering hearth before you catch something on fire in the garage ;-)

As a side note, since I prefer the flow characteristics of silver solder with cadmium to the cad-free versions, soldering outside in the open with plenty of fresh air supply is a "must do"....the hearth makes being safe easy.


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## Slipped Eccentric (Jan 2, 2008)

Process looks vaguely familiar . I've liked the look of these engines since I first ran across them a few years ago. Can't wait to see the final product.


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## clifforddward (Jan 2, 2008)

*More boiler work...*

More progress this weekend on the boiler. Today's job was to form up the outer wrapper and attach it to the throatplate. Traditionally this job is a straightforward one as the throatplate is made as a double flanged piece that is mechanically attached to the boiler tube and outer wrapper...then all is silver soldered together in one operation with the mechanical attachment holding everything in place during the heat...but we are not using traditional methods for this boiler...

The tab and slot construction method we are using on the Lawley build is making short work of the boiler, and I am excited that it is going together so quickly. However the non-flanged throatplate has been weighing heavy on my mind the past few days...with only tab and slot to hold things in place, it is going to be ill advised to do the boiler tube/throatplate/outer wrapper silver soldering in just one heat. If things shift during the heat with melted silver solder in place....well, let's just say I've had that happen a time or two early on in my silver soldering days and I don't want to even thing about making that mistake again! So for the Lawley boiler I'll make this joint in several steps. The boiler tube was previously soldered to the throatplate in one heat, and I'll be attaching the throatplate to the outer wrapper using two separate heats today.

First I prepped all the holes in the various pieces...most holes were made during the water jet cutting of the parts...but the holes need to be prepped before silver soldering...I decided to do this while the parts were still flat. Each hole gets chamfered on both sides using a larger drill bit. I have chamfer bits but for this operation the rougher texture resulting from use of a larger twist drill bit is better...it leaves a jagged chamfer on the hole, so there is plenty of room for silver solder to flow around the part that will later be attached. In addition to the rough chamfer, I used a small triangular file and made a series of notches around the inner circumference of each hole...so the silver solder can easily flow to the back side of the joint and make a good fillet. Also note the small holes for the stay rivets have also been treated the same way. This additional prep takes extra work but results in good penetration of the silver solder and water tight joints the first time...there are no shortcuts!




















 
Next comes forming the outer wrapper...at this point I must provide full disclosure and admit that I am a bit of an equipment junkie...I love quality tools and enjoy working with them...which means I'll acquire and use a new tool if I think it will produce a superior result. Having said that, I'll introduce my rolling machine...I picked this up some time ago anticipating rolling material for boiler work as well as metal roof pieces...I've bent copper around a mandrel in the past and yes, it does work, but I found using the rolling machine makes short work of the task and is extremely controllable. There are three rollers to the machine...the material is held tightly between two of the rollers, and the third is adjusted to result in the desired radius. Here is a photo showing one of the outer wrappers mid process:​ 





 ​ ​ Once formed, it was time to silver solder the outer wrapper to the throatplate. I decided to do this in two separate heats in order to keep everything in place. First I formed up a piece of ceramic firebrick that just fit inside the wrapper...during the heat, the assembly was placed vertically in the hearth, and the throatplate with already soldered boiler tube sat on top of this. I first applied flux just to the lower legs of the throatplate/outer wrapper joint...this joint soldered easily enough, and since I was not applying direct heat to the boiler tube, there was no risk of loosening that joint. After a short pickle and rinse to clean the parts, I set the parts up again...this time ceramic pieces were placed over the joints I just completed as well as around the lower third of the boiler tube/throatplate joint. I then heated and silver soldered around the upper half of the throatplate/outer wrapper assembly. As expected, the throatplate/boiler tube joint did go soft, but since I had provided support underneath to keep everything in alignment and had applied plenty of flux on the joint, all was safe and everything turned out fine with a good fillet of solder on both sides of the joint.​ A lot of words to explain the operation, but perhaps the photos below of the completed assembly will help explain. Images are taken after the final heat, with everything soldered and quenched, but before going into the pickle. Easily seen is the fresh, clean solder joint around the upper half of the throatplate/wrapper joint. Also note the area from the first heat on the lower portion of the throatplate/wrapper as well as the lower 1/3 of the boiler tube/throatplate joint that was protected from direct heat and not fluxed....this shows most clearly in the second image. Since this area did not receive flux during today's second heat and was protected by the ceramic bits during heating, there was no softening of the solder and only surface oxidation at the joint...this will all clean up during the overnight pickle in Sparex #2.​ 





 





 Not to worry about the appearance of the parts at this point...during each heat there is surface oxidation that takes place...some of this comes off when I quench with water rather than let the parts cool naturally...in the end all is good as soaking overnight in the pickle removes this oxidation and leaves a clean surface.​


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## clifforddward (Jan 2, 2008)

Hi Justin (Slipped Eccentric):
Sorry, I missed your posting on this thread last week. I have you to thank for the "tab snd slot" construction idea which was copied from your designs...it has made the boiler much faster to put together. And much of the decision to go use a dry backhead instead of a full wet firebox is due to proven success on boilers you and others such as David Bailey have built. 

I really appreciate the open sharing of ideas and techniques on this forum...makes a better hobby experience for all. I suspect the open sharing also drives more business for commercial boiler builders. For many, seeing all the steps involved in producing a high quality boiler confirms they should hire someone (like TRS and Justin) to do the construction work for them. In other cases it makes sense to get someone else to do the job when a group production run is being made. (I'm included in that group as my Hunslet is being converted by Train Dept & Justin as a part of their semi-production run). For those interested in learning how to make their own boiler for a one off design, seeing real projects being built hopefully adds a measure of information to the vintage publications available.

Having said all this, I discovered this morning that there were several lengthy threads a couple of years ago on boiler building. At the time I was between jobs and not very active on the MyLargeSteam forum...as a result I missed those threads. If my detailed accounts of boiler work for this Lawley build is duplication I am sorry...if desired postings can be minimized until the boiler is finished and I move onto frame work on the engine...or if folks find the boiler construction details helpful I am happy to continue...any thoughts?


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## hcampbell (Jan 2, 2008)

Don't stop posting! If anyone finds iyt getting redundant, they can skip ahead a bit.

Harvey C.
SA 1838


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## redbeard (Jan 2, 2008)

I can only speak for myself, but I can easily say keep posting!
Thank you for sharing!
Larry


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## llynrice (Jan 2, 2008)

Whether or not some of your work duplicates earlier threads, I really enjoy watching a project such as yours unfold in its entirety. I look forward to reading your ongoing posts.


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## Slipped Eccentric (Jan 2, 2008)

KEEP POSTING! Any sharing of ideas and techniques is good! Plus it's great to see that people are still out there building.

One thing I'd like to share, if you don't mind. When I get the front tubesheets cut I add tabs to them (3 or 4 depending on the barrel diameter) and cut notches into the barrel. That way, with the barrel standing vertical, there's nowhere but down into the notches for the sheet to go and it doesn't rock around allowing the the tubes, stays and barrel joint to be one in one shot.


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## clifforddward (Jan 2, 2008)

Excellent point Justin...wish I had thought of that when we cut our boiler tubesheets...as it is I'll need to determine a way to hold the tubesheet in place when I get to that soldering operation. For some reason we've designed the Lawley boiler to have the tubesheet soldered about a 1/4" down in the boiler tube...not sure why except that that's the way we've done it before on boilers with a flanged tubesheet. (Reminds me of a story about the newlywed wife who was asked why she cut off the end of the ham before placing in the oven to cook...her reply was that her grandmother had always done it that way...when the grandmother was asked to explain, she remarked that her oven was old and very small...the ham would not fit unless she cut off the end!).

Looking back at photos of your "tab and slot" boiler design, I see several things that could have been improved on our Lawley boiler design...but of course each project represents its own "learning opportunity". 

A funny story...Steve and I traded drawings back and forth at least a half dozen times reviewing the final boiler design for the Lawley, looking for things to improve. Then just to verify Steve had a prototype set of copper parts made to test the design before making boiler parts for the group...on the prototype set there was one joint where we ended up with slot on slot instead of tab on slot....we had a good laugh about that mistake!


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## StackTalk (May 16, 2014)

It is inevitable that there will be similar threads over the years as people come and go, and some of us 'discover the wheel' for the first time . . . and a refresher with some "things learned" blended in with tried and true techniques is attractive, so please do keep posting.

It isn't difficult to ignore something that is not of interest to a particular person. It isn't as if we are forced to read whatever appears in a forum, anyway. 

Cheers,

Joe


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## Two Blocked (Feb 22, 2008)

Hi Cliff; I think that I really like your slip roll tool. Would you please share the manufacture's name and where one may buy such a thing? Your work appears to be of a very high quality; spiffy and smart all a round.


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## Shay Gear Head (Jan 3, 2008)

Kevin,

You need to ask Cliff about his painting abilities. When will that brass engine get a coat or two?!


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## clifforddward (Jan 2, 2008)

The slip roll tool came from Baileigh:
http://metal.baileighindustrial.com/manual-slip-roll-sr-1220m
All of Baileigh's tools seem very good quality, although most are larger and geared toward production shops. I've got my eye on one of their 12" shears as a future shop addition.

HaHa Bruce....ask a few more times and I may keep that 0-4-0 permanently in brass just to aggravate you!...LOL!


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## clifforddward (Jan 2, 2008)

*Drilling holes in copper boiler...*

Before beginning final assembly and buttoning up of the boiler, we need to finalize design of the steam take-off, turret, regulator, and related piping. When building a locomotive from scratch, it is often the "devil in the details" items that cause the most trouble and wreck havoc with a building schedule.​ I've got several "key desires" for this project related to steam control:
1) Steam take off from within the steam dome on top of boiler...this will result in better steam for delivery to cylinders and should minimize the possibility of problems relating to priming.
2) Steam valve able to be removed for cleaning.
3) Clean appearance to backhead (can parts be hidden internal to boiler or in smokebox?).
4) Blower and related valve cleanly incorporated into steam take off, with enough steam supply to use with throttle supply without adversely affecting either.​ I probably won't be able to incorporate all of these in the final design, but I find having a list of desires helpful to provide some reference for working though various options...often desires compete and for me at least, in the end function trumps whims in the design process. 

I spent much of the day yesterday sketching, erasing, and tearing up paper as I thought through various designs. I also pulled nearly a dozen older books from my Model Engineering library studying how these matters have been handled by others over the years. I find older model engineering books to be a wealth of information when trying to solve "how to" matters. I've got a good idea of how I want to proceed, next I'll spend time at the lathe and mill making up parts to see how everything will fit.

Before moving to the lathe, I decided to go ahead and drill the hole in the boiler tube for the steam dome. I have a couple of Forstner type drill bits that I've re-ground to use on copper. The exact details of this are outlined in a number of M.E. publications, so I won't duplicate the technique here...suffice to say changing the cutting angles results in a bit that will not "grab" copper sheet as it penetrates the material. I've found that very helpful when cutting holes for tubes and related on boiler parts.

But for this drilling operation, where the surface of the copper sheet is a curve as on a boiler tube, the altered Forstner bit is not of much use...there is still a tendency to grab the material and create all sorts of trouble. At the suggestion of a UK Model Engineer forum posting some time ago I decided to try using a step drill to make this boiler hole. Turns out this worked like a dream...the step drill held things in place as the hole was drilled. I started with a center drill to make a small hole, then moved to a small step drill bit and finally to the larger step drill bit seen in the photo below. The idea offered here as something to add to your "bag of tricks" on your next project needing to make this type of hole:


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## BigRedOne (Dec 13, 2012)

I'm curious about drilling the steam dome after soldering the boiler. Wouldn't that leave chips inside the boiler, which would be difficult to remove?


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## clifforddward (Jan 2, 2008)

At the current time my boiler is not all connected, the boiler tube and outer wrapper assembly you see in the photo where the hole is being drilled does not have the firebox/tube assembly connected....so no problem with chips as they just fall right out of the boiler tube end.

I have in the past added holes to existing boilers...adding holes for bushings to several Roundhouse boilers for axle pumps, water gauges, and the like comes to mind. Yes, chips get inside the boiler, and yes, they are a bit of a pain to remove, but with enough filling and rinsing cycles it is possible to remove all chips. One should never be afraid to add a bushing if additional functionality is desired on one's engine. Important to note, however, that when you drill a new hole and add a bushing to an existing boiler, the boiler certificate is voided and a new boiler test is needed....all part of best practice for Model Engineering work...


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## clifforddward (Jan 2, 2008)

Over the past few days much research and conversation has occurred surrounding steam control for our Lawley project engine. Reviewing my key desires for steam control on the Lawley: 

1) Steam take-off within the steam dome on top of boiler.
2) Steam valve removable for cleaning.
3) Clean appearance to backhead.
4) Blower and related valve cleanly incorporated into steam take off.
Let's see how many of these we can incorporate in our design....

Many types of regulators have been used on live steam locomotive models over the years. For larger ride-on scales some of these designs get quite complicated....something we want to avoid.

Most current commercial models for use on 45mm gauge track use a simple screw valve located outside of the boiler, typically in a turret-type take-off located above the rear firebox area of the boiler. While simple to build and maintain, there are shortcomings with this design: 1) Most factory screw tips have a sharp angle and therefore fine control is difficult, 2) Steam exits the boiler in an exposed line, travels through an external screw regulator, and then is carried via an external line where it passed through a displacement lubricator on it's way to the cylinders...by the time the steam arrives it is substantially cooled, even if the line is insulated. A superheater if installed only helps a marginal amount...steam efficiency is diminished. 

Looking at the list of key desires, an ideal design for steam control would be one where the regulator is inside the boiler, with the steam exiting the regulator traveling directly to a superheater and on to the cylinders, with lubrication provided close to the steam chest. Oh, and in addition the design needs to be simple, easy to maintain, and fit in our relatively small boiler...a tall order!

Luckily our answer comes from a 1950s design by Martin Evans, long time editor of Model Engineering magazine. Martin Evans published quite a few locomotive designs over the years, and built much of his model steam design theory upon the earlier work of Curly Lawrence (pen name "LBSC"). I've always been a great fan of designs from both these gentlemen. My library includes several books by both Curly Lawrence and Martin Evans, and I refer to them often. 

In his design for "Rob Roy", a 3 1/2" gauge locomotive, Mr. Evans uses an internal screw regulator that satisfies nearly all my key desires:








Above is the drawing from Martin Evans' book for the regulator on his Rob Roy locomotive. As can be seen, steam take-off is from the steam dome, answering my first desire. and steam control takes place within the boiler where there will be no loss of steam as the outbound steam travels through the boiler to the tubeplace where it exits directly into the superheater assembly. But in order to use it on our Lawley and have it fit the boiler and backhead, we'll need to reduce the size of this regulator. Ideally we'd like the tube O.D. to be 1/2" rather than 5/8". 

We'll start this new, smaller design from the inside out, beginning with the meat of the matter. In the original Evans design, the cone shaped control rod has a 3/8" Witworth thread, perhaps chosen for it's coarse thread. We'll reduce this and use a 1/4"x32 ME thread, which conveniently enough matches the thread on Jason Kovac's Train Department improved offering for Accucraft locos:








This improved steam throttle valve has a sharper point for better control and two o-rings for smoother motion and a better steam seal. As a bonus it is reasonably priced, available, and provides a high quality component for this important part of the regulator. We'll need to extend the length of the shaft, but that will be easily done. Hopefully by starting with a narrower 1/4 throttle valve we'll be able to end up with a regulator that is 1/2" in diameter and will fit our Lawley boiler. Steve is working through some drawings now, then we'll make up test pieces to prove-in the idea before finalizing the backhead area of our boilers.

In the mean time basic boiler work continues....last weekend I got the backhead attached to the firebox wrapper, and this week am preparing the outer wrapper...in readiness for connecting the two major sub-assemblies of the boiler...the mass of copper is getting larger with each step...will need to pull out the "big torch" for the next silver solder operation.

More photos to follow....


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## clifforddward (Jan 2, 2008)

*Backhead attached to firebox wrapper...*

Today's update shows the backhead just after being silver soldered to the firebox wrapper. Set up was with the boiler assembly vertical (as shown by boiler on the right), with the backhead sitting flat on the surface of the ceramic firebricks. As can be seen there is a good solder fillet around the perimeter...only issue is that solder also flowed through where the slot/tabs were located and created four globs of solder on the face of the backhead...I'd rather have this excess to clean rather than risk not having good penetration. I suppose I do use more silver solder than necessary, and over time I'm getting better at not feeding in so much, but I do tend to err on the side of extra solder to assure full penetration, even at the risk of having excess solder to clean afterware....to each his own I suppose.

After this goes through the pickle I'll clean the excess silver solder over the next couple of evenings as I ready everything for attaching the outer wrapper to this firebox/boilertube assembly.


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## Steve Shyvers (Jan 2, 2008)

Cliff,
Thank you for sharing all the detailed info about this project. I considering building one of these in 16mm scale, but it was a more ambitious project than I was comfortable with. Then after doing some sketches I realized that with some Roundhouse parts on-hand I could make a model that captured the "flavor" of the NG6, but it would be 3/4 the size of a proper 16mm scale model of the NG6. Still a credible locomotive and still fun to drive with coal firing, but not a true scale model.

Steve Shyvers


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## clifforddward (Jan 2, 2008)

*Backhead attachment complete-Major subcomponents of Boiler assembled...*

Whew!...I'm glad to have this step behind me. This weekend's task is to finish attaching the backhead to the outer wrapper. The two major boiler subassemblies that have been worked separately will finally be connected. This means double the mass of copper to be heated to silver solder temperatures. Also the final opportunity for things to go massively wrong with alignment of boiler components. With so much at stake it is easy to imagine why I have been overly cautious approaching this task, checking everything multiple times as I move forward.

The photos below show the set up of components in the hearth. Only the backhead and immediate surrounding metal is exposed...by insulating most of the boiler with ceramic firebrick pieces the backhead can be heated to soldering temperature without risk of previous joints going soft. For this operation I have also placed several pieces of solder along the joint...these will automatically wick into the gap when the proper temperature is met. I'll then be able to add more solder to the area while under flame for full penetration:










I've placed a custom cut piece of ceramic on top of the backhead in the area where it is attached to the inner firebox wrapper...in an attempt to keep that joint from softening...with a dry backhead, this is a butt joint and I was concerned about losing the fillet of solder at that connection:









Let me tell you, this soldering operation required A LOT of heat! With the firebricks reflecting flame it was difficult to keep my hands close enough to apply heat and solder. I use TIG welding gloves for silver soldering as they are thinner and allow better control...in this operation I could/should have used my heavier stick welding gloves...nearly burned my hands on several occasions. But in the end, all was OK and everything soldered up correctly. Here's a couple of views after heat and solder application, cooling down with ceramic insulating pieces removed:


















I've discovered that butt joints handle molten solder much differently than flanged joints. It was difficult to tell if the joint was completely filled with solder. As a result I applied too much solder, ending up with excess in the foundation ring area to be removed. Not a big problem, just extra work. Here are the boilers on the bench after an overnight pickle and in the midst of clean-up filing work:









Still a long way to go before the boiler is finished...next comes more prep work and addition of the firebox stays...


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## clifforddward (Jan 2, 2008)

*Sievert torch parts...*

OK, time to tell on myself...some days I act like an idiot!

Those following this thread will remember my mention of the high amount of heat involved in my last silver soldering operation...my TIG welding gloves got toasted a bit as I was soldering the backhead onto the outer wrapper of the boiler. The reason occurred to me today as I was changing torch parts for my next soldering operation...I realized when installing the large burner tip for last weekend's job, I failed to add the longer neck to my torch, instead using the short 2" neck seen on the left in the photo below:








This meant my hands were 5" closer to the job than they needed to be...so problem solved and I hope not to repeat that mistake again!...LOL

On matters related to my Sievert Torch, I thought some might be interested to see the torch tip I'll be using to silver solder the boiler stays on the inside of the firebox. Since the firebox is a somewhat enclosed space, using a typical torch tip would be problematic...the air inlets of a standard torch burner are located up near the business end of the tip and do not allow a clean flame in an enclosed space. Instead I'll be using the burner on the right which has air inlets at the base of the burner (see the holes in the brass portion at the base)...Sievert calls these "Cyclone Burners". With the air inlet well outside the firebox, it will be easy to have a nice clean flame at the rivet stays inside the firebox.

Having a variety of burner tips for my Sievert torch has made it a very versatile tool in the workshop...


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## xo18thfa (Jan 2, 2008)

Gorgeous work Cliff. The tabs and notches in the copper sheets as part of the water jet job is perfect for assembly and holding everything in pace as you solder. It's a PITA to use pins and rivets to hold it all together.

Maybe you mentioned it and I did not see, but what are you using for pickle? I switched over to citric acid a while back. It is so much better and safer then battery acid.

I like the Evans design for the throttle. LBSC did some like that, but Evan's are much simplified. I think that throttle will be very responsive. Quarter turn or less from zero to full speed.

Here is a water gauge based on LBSC I use on "Nina". It works great, not hard to make.










And the parts


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## clifforddward (Jan 2, 2008)

Hi Bob:
Thanks for the kind words...for my pickle I use Sparex #2, which according to the MSDS sheet I have is primarily sodium bisulfate, the same stuff used in pool systems for controlling pH....we use it in a much higher concentration of course. I've heard good things about citric based pickle, but never tried it before...thanks for the info.

Funny you mention the water gauge. Realized I'll need to solder in the WG bushes as I attach the stays (so many things have to happen at the same time!)...For my water gauge, I'm going to use a right angle bush I made up for my 0-4-0 project engine...those will take me an evening or so to make up, so it will be into the weekend before I get back to the hearth.

As for the water gauge itself, thanks for the drawing and photos...it is a nice, clean, example. I'm toying with the idea of making a nutless water gauge to one of several designs that have been floating around...but as we have lots of room in the cab of the Lawley there may be no need for the more compact nutless design. I'm also going with larger 6mm diameter gauge glass, so my fittings will be increased in size to accommodate the larger tube. I've never had good luck with 4mm gauge glass delivering consistent readings, so I've abandoned the smaller tube in order to gain reliability.


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## Kovacjr (Jan 2, 2008)

Cliff, Looks good. I think you are the furthest ahead of the group with the boiler. Or maybe Steve is using you as the Guinea Pig, hahah soldering his up after yours. I did come up with a design for a nutless glass, call me one evening. Never made any more than some sketches that I cant find but its of a simple design. I did make a sample but have not installed yet.


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## David BaileyK27 (Jan 2, 2008)

Cliff, when I assemble boilers I leave the backhead until last, this enables me to silver solder the stays easier and I do not need a special burner, also you can check if the silver solder has run through as the stays can be inspected in the water space.
David Bailey


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## clifforddward (Jan 2, 2008)

Hi David...thanks for your comment...one question as I know you regularly use a dry backhead on your boilers...how do you assure a good solder joint on the top part of the firebox wrapper if you do the stays first?....do you solder the backhead with it in a horizontal position, and if so how do you get solder to the top of firebox area?....seems like the only way to do it at that point is with the boiler laying on its back with the open bottom of the firebox facing up....but then the seam around the perimeter of the outer wrapper is in a vertical plan and difficult to solder....or maybe you attach the backhead in multiple solder steps? I'm truly interested to hear your technique, look forward to your reply...


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## David BaileyK27 (Jan 2, 2008)

Cliff, my backheads protrude from the firebox wrapper so the boiler is stood verticle on the backhead for silver soldering inside and outside at the same time, if it is stood on firebricks which just support the edges then the back sheet can be heated from underneath and the silver solder will run round inside the box.
David


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## clifforddward (Jan 2, 2008)

Thanks David, got it...sounds like that would have been a better way to do our backheads...plus with the backhead protruding on sides and top, it could have provided the needed offset for outer cosmetic wrapper...Steve and I have discussed this since your post here, and we'll use that for our next boiler design...Thanks so much for the tip, it's a great idea.
Looks like I could have soldered the stays first, then in later step soldered the backhead inside and out. Oh, well, live and learn!
We're muddling our way through getting the stays soldered...not as easy as it would have been had we done them before the backhead, but looks like the stays will go in OK so all will be fine in the end.
That is one of the things I like about posting my activities and progress on this forum...I always appreciate the feedback and tips on how to improve my techniques in the future...all great information.


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## clifforddward (Jan 2, 2008)

*Decisions, Decisions....*

Seems like there are questions to be answered at nearly every stage of building a locomotive from scratch. While preparing to add stays on my Lawley boiler I realized the lower water gauge bush will need to be soldered at the same time. 

This led to an investigation of what bushing size to use so that I can attach a water gauge utilizing 6mm glass tube. Some may remember my other MLS thread posted a while ago...I obtained 6mm borosilicate glass tubing and then utilized a kiln to fuse a red line and white background to the glass. I settled on this larger 6mm glass tubing after installing a small water gauge with 4mm glass tubing on my 0-4-0 project engine...it was nearly worthless with inconsistent readings.

In addition to the small water gauge (which utilizes 3/16-40 bushing threads), I have several commercial units using 1/4-40 threads at the attachment bushing. This seems an attractive size as it fits the space I have allotted on my boiler quite nicely. In the photos below the commercial unit is the one painted red. 

I also have what I refer to as my "Go-To" box when it comes to any locomotive fittings...the box contains left over "bones" from a Mike Chaney Catatonk Climax...obtained from a fellow live steam hobbyist after his house burned to the ground a few years back. This box of parts has proved a valuable resource for information on how to scratchbuild locomotive fittings. Mike Chaney made all his own fittings and pieces for his engines, fabricated almost exclusively from material without castings. I consider each of his fittings a masterful design and true example of "form follows function" beauty. I've had several conversations with Mike Chaney over the years and he has always been very open and forthcoming with knowledge of the how and what of his fitting designs...I am very thankful for his gracious gifts of information.

The Water Gauge from Chaney's Climax (black in attached photos) has 1/4-40 fitting threads, same as the commercial unit. He utilized 5.5mm glass tubing which was somewhat bigger than the 5mm of the commercial unit....but looking at the comparison photo you can see the true meaningful difference...the inlet and outlet passages of the red unit (.100") are much smaller than the same passages on the Chaney unit (.165"). 

These small inlet/outlet passages are pretty typical of most commercial units I have seen...they all seem to follow drawings in older books, and most seem to have the passages much smaller than needed. I'm not certain why this is the case...maybe they are easier to produce, or perhaps it is just that manufacturers are following older published designs, then copying each other over the years....

























The I.D. of my 6mm glass tubing is .160"...by making my own water gauge and using Mike Chaney's gauge as a model, I can increase the body size slightly to accommodate my 6mm glass tube, have a 1/4-40 fitting, and keep the ID nearly identical throughout the assembly at .160"....So all will be perfect!

I could also drill out the commercial water gauge to have a larger hole for the inlet and outlet, but I'd still be left with the smaller ID of a 5mm glass tube. While 5mm tube works fairly well, I know that the larger ID of my 6mm glass tubing will work better. Since this is going on a coal fired boiler where I want absolute reliability from the water gauge, I'll go ahead and make my own water gauge...thereby one less thing to have to be concerned about while steaming.

OK, so having decided 1/4-40 threads will work on the water gauge bushing, I can proceed to make the parts and get to soldering the stays. Because of the way I want to position the water gauge I'll be making a custom right angle bronze bushing for the water gauge....but that's the subject of a future post...


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## clifforddward (Jan 2, 2008)

*Right angle water gauge fittings*

Moving along with making parts to be attached to the boiler, next is the fittings that will be used for attachment of the water gauge. These will be hard soldered during the heat used to attach the firebox stays. We'll be using the same right angle fitting I made for my 0-4-0 project engine...the design works well and provides a nice clean attachment point for the water gauge. I don't know where the design originated...I first saw it on engines made by contemporary model engineer Paul Pettipher who is quite active and makes most of the components and parts for his live steam engines. Like so many things in our hobby, I suspect the design evolved when one model engineer copied another...changing and improving things along the way.

Making the water gauge fitting is a straightforward machining job. There are quite a few steps involved as is typical of parts on our engines. Steve had some larger stock to work from, so he was able to machine the fittings using a technique faster than mine. The largest stock I had on-hand was 3/4" 932 bronze bar...not wanting to lose the Labor Day weekend while I waited for larger stock, I started by profiling the 3/4" material on my horizontal mill to get it to a point where I could start turning operations on the lathe. This is typical of how Steve and I work on our joint projects, we each use the tools and materials we have in our respective shops to make similar parts...materials and methods may be slightly different, but the resulting parts are nearly identical.

Here is my initial bar stock set up in the mill profiling the 3/4" stock that would become water gauge fittings:








After completing the outline profiling, I cut 5 pieces to start secondary machining on the lathe. I only needed 4 parts for my two locomotives, but when making parts like these involving many steps I always make an extra part or two. I don't want to be forced to start over from scratch making replacements in the event I make a mistake while machining. It takes little additional effort to make the extra part.

I won't bother showing all the steps required to complete the water gauge fittings, but to give an idea of what is involved, here are a series of photos showing steps used just to drill and tap the horizontal hole of the water gauge. Some will look at the many steps below and feel it is possible to "get by" with fewer operations. Yes, it can be done, but the end result will suffer and function may be affected later...it is the fit and finish of each aspect of a live steam model that determines how well our locomotives perform. By taking the extra effort to drill and tap straight and clean holes, I can be assured of good sealing properties...one less thing to worry about when operating the engine.

1) First comes locating the fitting in the 4-jaw chuck of the lathe, and centering on the hole location. While many shy away from using 4-jaw chucks, they are in reality easy to set up and use. For "pretty close" type work like this fitting, it is possible to use a center punched mark on the part and tailstock center in the lathe to make short work of centering the cutting tools over the hole location. I typically get within a few thou using this method, and for many parts this is plenty close enough. All a matter of understanding what tolerances are required where.








2) Next comes starting the hole with a center drill. It takes only a bit of additional time to use a center drill, and it makes a HUGE difference in the success of the final hole...ALWAYS start drilling operations with a center drill.








3) Now use the twist drill bit to cut hole to 90% of final depth. Since the hole was started with a center drill, the twist bit cuts easily and straight. I'll be making this a flat bottomed hole using one of my D-Bits in the next operation, so this twist bit is about .005" smaller than final hole size.








4) Here's the D-Bit in use...opening the hole to final diameter and cutting to final depth. D-Bits cut much like a reamer, but seam to cut more cleanly in brass and bronze in my opinion. In addition, as can be seen from the shape of the tip of the D-Bit, the final hole will have a flat bottom. This will allow minimal clearance on the far end of the water gauge fitting. There will be about .015" of material between the bottom of the hole on the far end of the hole to the far outside surface of the fitting.








5) Now we change to the tailstock tapping holder, and run through the series of taps. I'm only showing one photo, but actually started with a taper tap, and afterward used a bottom tap to finish things up since this is a blind hole.








6) Final step is to chamfer the edge of the tapped hole. Without this chamfering there would be a raised edge around the hole opening and it would be more difficult to get a good seal on the water gauge screwed into this hole. Attention to detail is the hallmark of good craftsmanship...we owe it to ourselves to always do our best work!








And there you have it, the completed parts:








After a bit of clean up work with a file, and a small hole to be drilled in the tab for a tiny copper rivet that will be used to keep the fitting located during the heat, these fittings will be ready for silver soldering to the boiler.


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## clifforddward (Jan 2, 2008)

*Final prep of boiler for adding stays*

Final prep of boiler for silver soldering stays. The holes were water jet cut into the outer wrapper...here I'm drilling through those holes to make matching holes in the firebox. 








Once the holes are drilled, next comes clean-up with the file. Since it is not possible to chamfer the holes in the water jacket, a file is run between the wrappers to knock off any swarf hanging on the hole in the tight water space. Equally important is cleaning all the stray bits at the exit point of the holes inside the firebox. The holes need to be as clean as possible so that solder can flow easily.









In order to drill the two stay holes on the front of the throatplate, I had to make an extension drill bit since there was not enough clearance for my drill chuck. A piece of 3/8" steel rod from the scrap bin, a few minutes on the lathe, and a quick epoxy of the .1275" drill bit in a hole drilled into the end of the rod creates this extension drill bit. I'll save this along with my other specialty built boiler tools.


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## clifforddward (Jan 2, 2008)

*Trouble in Paradise...Today's job is repair and move forward....*

Several have written to me directly indicating these posts showing progress of my 7/8n2 Lawley locomotive have been both encouraging and helpful. Toward that end I feel it important to let followers know not only of successes, but also failures. Today we take a look at one of those setbacks, and evaluate causes and corrective actions...

Yesterday I started silver soldering stays in the boiler. I'm using 1/8" x 1" copper rivets for the stays, with the head inside the firebox. The firebox is a tight area, being 2 1/4" square in cross section at the widest point. A lot is going on in this small space, with much that can go wrong when heat is applied. As I soldered the stays on the first boiler things did go badly. When solder started to flow, the heat in the firebox caused the solder to soften on the seam along the front top edge and along one side of the firebox...both seams opened up. On my past boilers this was a flanged joint and any softened solder would stay in place with a mechanically riveted joint. Since we are using butt joints on this boiler there is nothing to hold things in place when the seam went soft, so the joint easily opened up. Steve and I both had this problem...so we'll be re-thinking either the design, our order of operation, or probably both. 

In retrospect we would have had an easier time by soldering the stays before attaching the backhead. To make that change we'll need to re-design the backhead and how it is tabbed into the wrappers...too late for this project, but certainly something to consider on the next. That is the way it is for model engineering...each project provides skill learning opportunities for the next.

After a pickle and inspection, next comes how to repair. Both the top and side seams had pulled away and left about 1/16" gap. I could get a steel rod down the boiler tube, so I was able to knock the firebox front back into position. To keep more parts from loosening when I did the repair heat, I sliced some thin sections of ceramic brick to act as insulators for the rest of the firebox. I fluxed up the area, positioned the boiler so the top seam was horizontal and slightly tilted to the front....then applied heat to the front top seam area. In the photo below the repair can be seen...I flooded the area with solder and made a large fillet over the joint. In addition I applied addition solder around each firetube to make certain there would be a good seal around each tube. The repair is sound, and while ugly will work fine...This area is not one that will be seen, so function is the primary consideration. The open seam on the firebox side shows clearly along the vertical seam in this photo...I'll be fixing that during today's silver solder activity.








For my second boiler, I cut thin slices of ceramic firebrick and used that to insulate interior sections of the firebox I did not want to see too much heat. While this worked well to keep the wrapper and other seams from opening up, it also decreased the working area inside the firebox. As a result several stays did not get properly attached in the first heat and I'll need to redo those areas. But better to reheat the stays than repair a firebox seam, so all in all I'm satisfied with the revised technique for this project. Here's a view of the stays on the second boiler...there are five stays I'll be heating again.








I'm back at it this morning, and hope to have better success today soldering the stays on the other side of the boiler. Once work is finished inside the firebox it should be a relatively simple solder job attaching the stays on the outside of the boiler...plenty of room to work and easy to insulate surrounding areas.


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## clifforddward (Jan 2, 2008)

Boilers out of the pickle and time for inspection…

Boiler stays on first side now complete…after a second heat all stays now have good solder joints.








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My repair to the firebox wrapper seams have been successful (photo below)…very ugly, but all joints sound and hopefully I’ll be able to keep them together in subsequent heats when I attach the stays on the other side of the firebox.









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On close inspection I discovered a slight opening along the top front edge of the firebox wrapper on the second boiler (opened seam is behind the longer firetube in photo below, although it does not show well in image)…will need to go in and flood some solder there to seal things up…the seam did not pull open more than 1/32", just a slight void of solder with a small gap that must have melted out as I was heating other parts of the boiler…it was the only seam inside the firebox that did not have a large fillet of solder material. I’ll take care of that next before moving to attachment of stays on other side of the boilers.







This image has been resized. Click this bar to view the full image.








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One thing I did differently...when I soldered the stays on the outside of the boiler I used some 45% silver solder I have with a melt temperature 15-20 degrees cooler than my normal stuff which is 50% Silvaloy-50. Seems to have helped keep surrounding material from softening…I am going to use the lower melt solder for stays on the other side both inside and out…hopefully will help keep wrapper seams from softening.


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## clifforddward (Jan 2, 2008)

As a point of reference, the inside of the boiler firebox is only 2 1/4" wide...which means depending on the monitor you are viewing with, the images above are 2x to 3x larger than life size...The area to work inside the firebox is VERY tight and it is proving to be a challenge to get everything soldered up properly. Both Steve and I have had to come up with unique insulating techniques to protect areas from subsequent heats.


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## FHPB (Feb 25, 2011)

This is of no use to you now, but I'm thinking about the reheating problems and wondering what kind of mechanical solution there might be to keep those butt joints solid.

Harry Wade drills tiny holes and ties the bits together with copper electrical wire, which he clips or files off after the joint is finished. If you left those in place, the parts would stay where you want as subsequent parts are soldered on.

Perhaps some tabs could be cut a tad longer, with a hole punched just beyond the surface of the slotted piece, so a "peg" of wire could be inserted to keep the tab from moving out of the slot when reheated?

Just thinking out loud here. This construction method is ingenious and enlightening, in addition to being more efficient. Great way to make use of the cutting technology in ways that can't be done (reasonably) with hand-formed parts!


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## clifforddward (Jan 2, 2008)

Vance, I think you're onto something there with your idea about longer tabs, bits of wire, or some means of mechanically holding things in place. Steve and I have had many conversations about the issue (some with off color language!) as we work through the challenges we have both faced.

This boiler is our first attempt at using tab and butt jointed construction. I know others have done it before; perhaps not so many with the complexity of a wet firebox. The tips David Bailey shared about using a protruding backhead and a different order of operation is being incorporated in new boiler parts still to be cut for the fourth member of our build group. And I'll take your comment as an action item and reach out to Harry Wade to see if he can provide some nuggets of wisdom from his perspective.

I know Justin uses the tab and butt joint technique with great success...I hope to sit down with him sometime this fall/winter to hear what advice he can share.

While the water jet cut parts clearly save a huge amount of time preparing individual boiler pieces, clearly there is a learning curve to making best use of the technology. It has been a good learning experience for both Steve and me. Hopefully the other two fellows in this Lawley build will be able to learn from our mistakes and have an easier time.


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## clifforddward (Jan 2, 2008)

*Work inside firebox now complete!...Yay!*

A busy weekend of boiler work here. I was able to repair the seams inside the firebox, then got to work adding stays to the left side of both boilers, as well as adding the two stays connecting the firebox front wall to the throatplate of each boiler. 

Since the water gauge fittings are hard soldered to the boiler, and one of them sits between two rows of stays, it made sense to solder the water gauge fitting during the same heat as the outside of the stays. For the top and bottom water gauge fittings, I've made a jig to hold everything in alignment during heats. This is critical so that the water gauge will line up and function properly. Here you see the boiler, with jig in place, fluxed up and ready to be heated. I've placed several wraps of 1/32" 45% silver solder around each stay, along with several lengths of solder along the top and bottom of the lower water gauge. Note there is NO flux anywhere around the jig parts...we don't want to permanently attach the jig to the water gauge fitting!









Here's the boiler set up in the hearth...Most of the boiler is hidden underneath plenty of insulating firebrick pieces placed to protect previously soldered seams. As this project goes along I'm getting better at planning the heats and doing a better job of set up:









And a close up showing firebrick pieces carefully protecting prior work:









And a view after the heat...good solder joints on all stays, and the water gauge fully attached with a nice fillet of solder all around. I'll remove the jig before placing the boiler in the pickle (The jig parts are steel...and steel should never be placed in Sparex #2, it will ruin the batch). 








After the pickle, I'll do the set up again in order to solder the top water gauge fitting...with the boiler arranged such that the upper water gauge fitting is sitting horizontal for the heat. Silver soldering works much better when parts being joined are horizontal for the heat.

With the stays done next comes fitting and attaching the foundation ring. We also have several flanged bushes to design and attach to the boiler. So several steps remaining before we can pressure test the boilers...


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## bille1906 (May 2, 2009)

Hi Cliff
You work is beautiful and you are really taking the time to do everything right.
One thing I do that may make the stays easier to solder is that I use bronze rod or copper electrical wire vs the rivets. it looks like it may be hard for the solder to get under the rivet heads. Before I put the cut stays in the boiler, I flatten the end out slightly with a hammer on an anvil or vise. Just enough to keep it from slipping through. The hole in the fire box gets a slight bevel by hand with a countersink and the other end of the stay is flattened with a large pair of vise grips or cut partially through with dikes. the main idea is to have a valley around the stays for the solder to flow into.


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## clifforddward (Jan 2, 2008)

Thanks for your comments Bill. There are always several methods to perform each of the construction steps on our live steam locos...good to hear the details of your technique for adding stays to the boiler. Hopefully this thread and all the related posts will serve as encouragement for more folks to dive in and start their own project!


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## bille1906 (May 2, 2009)

Yes
Sometimes I post something and get no comments and wonder if anyone is even following it
A good thing about responding to a thread is that you become subscribed to it and get email notices when someone posts


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## clifforddward (Jan 2, 2008)

*Flanges for the boilers*

Before finishing the boilers we need to sort out the various flanges....as several have pointed out it would have been good to have finalized all this in the beginning...problem was, we have been changing our minds along the way about exactly how to address the dual safeties on the safety valve dome. Additionally I'd like to build one of the internal regulators we want to use before finalizing the large flange needed on the backhead to accommodate the regulator.

We're using flanges rather than screw in bushes in order to assist with keeping the various bolt on items in proper alignment...plus I like the look of flanges and nuts on studs rather than screwed fittings.

This past weekend I got a good bit completed on the safety valve flange and the flange for the turret at the top rear of the boiler. In addition, I was able to trim the completed stays and clean up the boilers a bit. In the photo below you can see I still need to drill the flanges for the 2-56 stainless steel studs I'll be using. My rotary table is quite large for this job, requiring bushings to be made to accommodate the .375 & .500 spigots on the flanges in the .625 hole in the middle of the rotary table. One of the turret flanges is set up on the table now...this will be mounted on my Benchmaster vertical mill and then carefully drilled with a blind bottom hole to keep silver solder from filling the stud holes when attached to the boiler.








Used my typical "sketch pad" designing technique to figure these out...a pretty tight fit for the studs and nuts, so I like working quickly with sketches for these sorts of jobs rather than making Steve go through the trouble of drawing things up in CAD.

There are dual safeties on the Lawley...rather than try to make a functioning Ramsbottom safety valve, I am making provision to mount two pop-valve safeties on the safety dome. The outer dome will be turned in one piece and then bolted down onto the silver soldered flange on the boiler. Once I drill the holes for the studs I can determine if there is room for a sealing O-ring, or if I'll need to use a sealing gasket for the connection. I'm leaning toward use of a "dollar bill gasket" as there is a nice flat surface between the two parts for sealing, and I should rarely need to take this connection apart.









The turret flange is a very straightforward turning job...just had to be careful of the overall size as it will fit on the portion of the boiler that is inside of the cab...the size below will provide .093 of clearance with the cab front wall:









Now that the turret flange is sorted I can proceed to drill that hole at the top rear of the boiler...should be soldering the fittings on that area by the weekend.


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## clifforddward (Jan 2, 2008)

*More Boiler Flange Work....*

Work and family commitments have kept me from the workbench...finally got time to hard solder the flanges on top of the firebox wrapper, including safety valve flange, turret flange, and upper water gauge fitting. First an image of the set up in my hearth ready for heating:








And a photo post pickle and cleanup:








I had waited until now to solder the tabbed stays connecting the firebox top to the outer wrapper...this was a mistake as the slot/tab clearance on these parts opened up during various other operations. It would have been better to solder those much earlier in the process before I connected the backhead and other parts. The slot/tab connection was under the area of these flanges on top of the wrapper...I erroneously thought it would be better to solder these all in one heat. As it was I had to insert a copper filler piece to close up gaps to a point that the silver solder would fill. 

More lessons learned as I work through gaining a full understanding of how to manipulate this tab and slot boiler construction method. In spite of the challenges I have enjoyed the learning process on this boiler, all part of the process of continuous skills improvement.


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## JimB (Jan 25, 2013)

Cliff, I've been enjoying this and am learning a lot. Thanks for posting.

One question on the last series showing the flanges. Where did you apply the flame? Directly on top? Thanks James


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## Larry Green (Jan 2, 2008)

Cliff, do you know if Sparex #2 is suitable for cleaning soft-soldered brass assemblies?

Enjoying watching your (speedy) progress.

Larry


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## clifforddward (Jan 2, 2008)

Sorry Larry, can't help you with an answer...I've never used Sparex #2 for cleaning flux residue when soft soldering...for soft solder I just use dawn dishwashing detergent in hot water with an old toothbrush.


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## clifforddward (Jan 2, 2008)

Hi Jim:
Regarding your question about where heat is applied when hard soldering the flanges, first I try to isolate the area by using the ceramic brick pieces to insulate everything except the parts I actually want to solder together. Then I slowly apply heat at first to "burn off" the liquid of the flux paste...it will turn to a gel, then somewhat hard....from there I continue heating the parts, with most of the heat applied to the bigger mass of metal, in this case it is the flanges themselves. By concentrating the heat on the flange, plenty wraps around and heats the boiler wrapper the flange is being attached to. As the parts approachs temperature for soldering, the flux will become very liquid and flow easily...at this point I press the end of the solder in the joint...when the parts are hot enough the solder will quickly melt...it may be necessary to use a "scratch tool" to get the now melting solder to actually start flowing into the joint...once the solder starts to flow in the join things will happen very quickly and you will find the solder flows easily into the tiniest gaps. My scratch tools are sharpened lengths of 304 stainless rod, about .125" diameter, with the tip ground to a point. The end I am holding is bend in a loop which serves as a handle...I'll try to remember to take a photo of my scratch tools next time I am at the hearth.

Hope this explanation helps...it is one of those operations that is best done in practice rather than reading about it. Try connecting some scrap pieces via hard soldering...I did this and soldered maybe 10-15 joints before I ever tried to connect any "real" pieces using silver solder. Practice is truly the best teacher when it comes to silver soldering.


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## bille1906 (May 2, 2009)

A good scratch tool can also be made from coat hanger material. This can also be made into springy clamps to hold things in place while soldering and it is cheap


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## JimB (Jan 25, 2013)

Thanks Cliff, I have silver soldered a small boiler and gas tank following Kozo's guidance. But the size of boiler and special fittings that you are working on are in a totally different category from what I have worked on. 

It looks like you are using plenty of silver solder and I had not thought of wrapping everything with fire brick material in a "Fire Pit". It must work well from the results. 

Jim


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## clifforddward (Jan 2, 2008)

Yes Bill, you are absolutely correct, coat hanger material makes an excellent scratch tool...the first one I made was from a coat hanger and it still hangs on my hearth and gets used...It is bent all to heck, rusted, and the tip no longer a sharp point, but I still reach for it more than I care to admit. I can't bring myself to throw it away...in spite of having several similar sized 304ss scratch tools hanging nearby. A little bit embarrassing, but perhaps we all have one of those "temporary tools" that becomes a permanent fixture on the bench...LOL!

Jim, you'll find your experience with the small boiler and gas tank you mention will translate nicely to larger sizes...and following the guidance in Kozo's books is spot on. Only difference between small parts and bigger assemblies is the need for more heat (bigger torch tip), and enough patience to allow time under the torch for everything to come up to the proper temperature for soldering...Sounds like you are in better shape than you give yourself credit for...Don't be afraid of taking on a bigger silver soldering job, there are few situations that are not correctable.


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## John Hilton (Oct 23, 2014)

Cliff. In your picture of the regulator there are two O rings fitted. I want to build a similar regulator for my 3 1/2 gauge model, but can't source O rings that suit the temperatures involved. Mostly they have a maximum temp of 123 degrees C. Can you recall what you used please?
Many thanks

John


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## clifforddward (Jan 2, 2008)

Hi John:
Those O-rings on the regulator are most likely Buna-N. We'll be using Buna-N or Silicon O-rings for all of the various places that incorporating an O-ring for sealing. Buna-N is good for 250f and Silicone up to 400f...this will handle temps for all areas except perhaps the smokebox. Certainly the area surrounding the regulator can be handled by a Buna-N O-ring as it is wholly contained in the steam area of the boiler. I'm anticipating using a Silicone based sealant for the wet header where the regulator exits the boiler at the front tubeplate. Since the internal side of the tubeplate sees boiler water, it is unlikely that the wet header will approach the upper temp limits for silicone. 

I will have a SS superheater line running from the wet header back into the large firetube...since the superheater line runs back up to the interior of the firebox, it will see considerably higher temperatures.


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## John Hilton (Oct 23, 2014)

Thanks Cliff. I will look into Buna-N.
This afternoon I made a "dummy" regulator like your one. My thread was 3/8 Whitworth, 16 tip, so on a regulator handle turn of 1/3 max I should get about 20 thou opening. I had adopted a gentle taper, but on test I don't think I could get enough steam down the pipe. I will try it with a much sharper angle on the screwed valve next week, but I just wondered if you had been able to test your regulator under compressed air to see if it has enough puff. 
My loco chassis is already air running, so that would be a useful test for me to see if the regulator will drive the loco under compressed air.

Keep up the hood work. Regards

John


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## John Hilton (Oct 23, 2014)

Ps I hate this predictive text!


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## clifforddward (Jan 2, 2008)

Steve and I are just now building up the regulators...sorry, I do not have any test info to offer. The regulators are the current bench project for both of us, so I do anticipate we'll have some info to report in the coming days/weeks.

Our Lawley regulators will have an overall diameter of .500"....the one in the drawing I posted is .625" diameter and was for the LBSC "Rob Roy" locomotive which is a larger 3 1/2" gauge engine. I would think you should be OK building it directly to the sizes noted in the drawing and come out OK for your engine...In our case everything is being downsized as possible, time will tell if the smaller sized regulator functions properly in our boiler.

BTW, you should have an "edit" button at the right-hand bottom of each of your posts...this allows you to go back and make corrections to your postings as needed...with my stumbling hands I end up editing my posts all the time!


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## xo18thfa (Jan 2, 2008)

Nice work Cliff.

Two other options for O rings are Viton (good to 400F) and PTFE Teflon (good to 500F)


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## John Hilton (Oct 23, 2014)

Bob.
Yes I have now been told to look at Viton O rings. They are cheap and available online.
Provided soft solder melts before the O ring gives way I think they would be quite safe as boilers that have a content of soft colder don't seem to melt! 

Cliff - looking forward to reports of your progress - beautiful work. Your boiler pics have been a great help to me with my own build.

John


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## clifforddward (Jan 2, 2008)

*Foundation Ring: Fitting and Soldering...*

This week's work was fitting and soldering in the foundation ring (aka "Mud Ring"). We're using the traditional method for making the foundation ring...fitting a copper bar around the gap between the lower part of the firebox and the outer wrapper. Had we left the throatplate and outer wrapper long on the bottom edge we could have used what some modern folks are doing, bending over the lower edge extension by 90 degrees to create the foundation ring. Perhaps on a future boiler project I'll give that method a try, but for now we'll proceed with things in the traditional manner. 

The gap in my foundation ring area varied from .150" to .188"...plus I did not have any 3/16" copper bar stock. So I milled down some 1/4" copper bar I had and commenced to cutting and filing to fit the various pieces. I also drilled and installed 1/16" copper rivets to hold the copper bar in place. While it might be tempting to use a friction fit, don't fall victim to that shortcut as the pieces are likely to move around as everything is being heated. I made the copper rivets a very sloppy fit so that solder would easily flow though all joints and through the rivet holes themselves.

Here is the boiler set up in the hearth ready to heat. You'll notice everything is insulated with ceramic brick except just the portion needing to be heated:









And a view as I am starting the heat. With the mass of the boiler and the large amount of copper contained in the foundation ring, it will take quite a bit of heat and a long time for everything to come up to the right temperature. For me this took 5+ minutes before the solder started to flow. Don't rush the process as soldering will be impossible before everything is fully up to the proper temperature and very easy once proper temperature is achieved.








I did this soldering after nightfall so I could easily see the flame and follow the molten solder. After moving the flame back and forth around the foundation area, as soon as the solder started to flow I started from one end by using the scratch tool to get the solder to flow into the joint. Once things started to flow I was able to add additional solder just in front of the torch flame and work my way from one end to the other. With the dim light of the flame I was able to see not only the solder flow into the joints between the copper bar and the wrapper, but also verify that solder had flowed fully through the holes containing the copper rivets.

Here's what things looked like immediately after finishing the heat.








After an overnight in the pickle, it was time to do a close inspection. Since several have written and asked what a good solder joint should look like, I am including several photos here showing the various joints. Note the nice filet of solder along each copper bar joint, and the good filet surrounding each copper rivet:
































In order to verify I had good penetration of solder to the inside edge of the copper bar pieces making up the foundation ring, I carefully inspected the area visible through the hole in the throatplate that would later be the drain bush. In this photo you can just make out the filet of solder on the inside seam of the copper bar:








The copper rivets were used only to hold the foundation ring pieces in place. Next I'll grind them flush on the inside and out. Use of a Dremel tool makes short work of this task. I actually use an ancient Dumore grinder...here are a couple of shots showing my flexible grinder arrangement as well as the tackle box I use for organizing tooling for my grinders:
















And a photo here of the finished product...foundation ring in place, with all surfaces cleaned up:









Time now to move on to the steam dome for the top of the boiler tube. That will also require finalizing the internal regulator...


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## JimB (Jan 25, 2013)

Thanks for the excellent photos Cliff. I'm learning a lot. Jim


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## clifforddward (Jan 2, 2008)

Before we make and attach the flanges and bushings for the backhead and front tubeplate, we need to finalize the regulator for our Lawley project. We're using an internal regulator for the Lawley project...this type is common enough in ride-on sized models, but fairly uncommon for garden sized trains. Most garden sized live steam use an external regulator coming off either the backhead or attached to a turret on top of the boiler.


Internal regulators have a lot of advantages...by pulling steam from a riser pipe up inside the steam dome, priming is nearly eliminated, with only steam delivered to the steam line. In addition having the regulator itself fully surrounded inside the boiler with the steam line running inside the boiler up to the smokebox and on to the superheater means there is no opportunity for condensation in the steam line. There is the disadvantage of being much more difficult to make than an external regulator, but that's why we do this stuff anyway, to improve our skills, right?!


If we can successfully build this internal regulator it will become our standard steam control assembly for other locos as well...it should be quite useful when we get back onto the K1 project.


Followers of this thread will remember I am basing my Lawley regulator design on that used by LBSC on his "Rob Roy" locomotive. Actually similar designs were used on many of his locomotives, it just so happened I have the book for this loco and used it as my starting point. The Rob Roy regulator is 5/8" diameter, and we want to reduce the diameter of ours to 1/2" to avoid clutter on the backhead. I'm also incorporating a steam valve from The Train Department that has a more acute angle on the cone as well as twin O-Rings for sealing.


For me these sorts of design projects end up being a combination of sketches, test turnings, the "rinse and repeat" until the final design is worked out. I knew there would be multiple generations of test cuttings for this part, so I worked in brass rather than cut into the more expensive bronze that we'll be using on the final parts.


After a fair bit of trial and error (mostly error) here is the current drawing of our regulator design:








Since the critical workings are internal to the assembly, the only way to verify things are working properly is to make a trial part, then cut it in half to study the layout. Here is the final design built to the drawing above:








Because a variety of special drills, reamers, and taps would be involved, it was decided that I would make the regulators for the entire group...that means 4 identical regulators, two for me, one for Steve, and one for Mark. Now making one precision part that fits itself is hard enough...making 4 identical ones takes things to an entirely different level! To assure making identical parts, I also developed an "Order of Operations" document to track each step of manufacture. For the internal portion of the regulator this turned out to be 25 steps:


Steam Valve Prep:
 1) Remove two o-rings
 2) Chuck in lathe with 3/16”collet holding throttle shaft end.
 3) Turn down body to .2305”-.231” (prototype is .2305’).
 4) Check clearance in regulator
 5) Re-installed o rings.


Main Regulator Body:
 1) Set up lathe with ½” collet
 2) Face ½’ Diameter Bronze piece to 2.055”
 3) Turn down one end for .250” length to approximately .430-445” diameter for tight fit inside thick walled ½” stainless steel tubing (cut tubing to approximate length first for fitting). Use Lathe bed depth stop indicator.
 4) Center drill for #45 drill bit below.
 5) Drill through with #45 bit (use extra length drill bit).
 6) Drill through with #43 bit (use extra length drill bit).
 7) Ream through 3/32” (.9375”).
 8) Drill #24 to depth of 1.625” using markings on tailstock quill.
 9) Drill 5/32” D-bit to depth of 1.680” by setting D bit to full depth in chuck when bottomed out.
 10) Drill #1 to depth of 1.00” using tape wrapped indication on drill bit.
 11) Ream 15/64” to depth of .1.025” (as measured from end of tip on reamer…use tape wrapped indication on reamer).
 12) Drill 4.2mm to depth of 1.365” using tape wrapped indication on drill bit.
 13) Tap M5x.0.8 Starting Tap to depth of 1.40” (as measured from end tip of tap…use tape wrapped indication on tap).
 14) Tap M5x.0.8 Bottom Tap to depth of 1.40” (as measured from end tip of tap…use tape wrapped indication on tap).
 15) Reverse body of regulator, drill #21 to depth of .255” (as measured from end tip of drill bit…use tape wrapped indication on bit).
 16) Tap above hole 3/16x40 ME with starting tap and then bottom tap for depth of 2.15” (gently bottom out in hole).
 17) Chamfer front edge of regulator body using turning tool to make 1/8” chamfer.
 18) Move to Benchmaster Mill for this operation…Clamp regulator body and drill through side at point 1.50” from rear end of regulator body. Drill using 5/32” end mill to depth of .250”.
 19) Tap above hole 3/16x40 ME with starting tap and then bottom tap for depth until taps gently bottom out in hole.
 20) Return regulator body to lathe and re-run 5/32” D-Bit to clear burr from above operation. Be careful to just clear burr and not drill to additional depth. (depth for this is 1.680”)


This listing is not meant to be an instruction list, but rather provide an idea of the complication involved in a seemingly simple assembly. As it turns out detailed review of the final design revealed that we can reduce the diameter from 1/2" to 7/16" with plenty of clearance left for all internal functions. So I'll be revising the drawing and Order of Operations document to fit the smaller diameter. That's what I'll be building for the production units. I'll be making 4 regulator assemblies plus a couple spares to assure I end up with four good units.


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## bille1906 (May 2, 2009)

Cliff
Nice cutaway photo
I assume you will seal the inlet thread with high temp RTV or loctite when you assemble it and the front tube sheet is still off to allow you to put it in place???


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## Kovacjr (Jan 2, 2008)

Very neat Cliff.


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## clifforddward (Jan 2, 2008)

Bill:
The vertical steam inlet pipe will actually be threaded...I ended up forgetting to cut it before sectioning the cutaway, so threads are missing in the prototype cutaway part...will be in the production unit.

The tubeplate will be soldered in place with all bushings included before the regulator is installed.

Regulator assembly goes in through 1/2" hole in flange at backhead...front steam outlet pipe is permanently threaded and sealed to front of regulater...after inserting through hole in backhead the unit is screwed into threaded flange in front tubeplate...with sealant there to seal threaded connection. Length is fixed such that when regulator/steam pipe assembly is screwed home the front is fully threaded in, flange at backhead is flush for bolting up, and the vertical inlet hole is lined up underneath the steam dome flange....vertical pipe is then screwed home with sealant, and inner steam dome is attached making all pressure tight.

Hope my description helps...photos of all this will help once I get to that point.


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## clifforddward (Jan 2, 2008)

*The Old Dog learns a new trick....*

Added a new skill to my "bag of tricks" over the weekend, namely silver soldering stainless steel. 

Since our regulators for the Lawley will be fully enclosed in the boiler, all sub-components need to be bronze or stainless steel for long life and reliable operation. For extensions to the steam valves we are using, this means attaching a .156" stainless rod to the end of the commercial steam valve. Bronze is not available in this diameter, and no other material would hold up as well inside the boiler.

A while back I picked up some high temperature silver solder flux, made precisely for the higher temperatures and longer heat required for silver soldering stainless. I was somewhat tentative about the operation, but all turned out fine...I used my Microflame brand jeweler's torch for this job since it was fairly small...I wanted good control and I also had a special torch tip (seen in the photo) that sends two flames out to heat up both sides of the part at the same time.

















From now on I won't shy away from use of stainless steel in assemblies for my locomotive. With an increased strength and superior corrosion resistance it will be a good material to have for use in a number of areas, not just inside the boiler.


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## bille1906 (May 2, 2009)

Cliff
I have also found stainless easy to solder. When in doubt, I use 50% but I have found that 45% works also. 
It also does not transmit the heat like copper and brass and is good for boiler knobs and such where you don't want to get your fingers burnt.
The only caution in using it in boilers is that some alloys are more corrosion resistant than others. I have seen them described as corrosion resistant and highly corrosion resistant??? I think the best thing is to test it with a magnet. If it is magnetic at all, don't use it


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## clifforddward (Jan 2, 2008)

Interesting tid bit of info about magnetic stainless Bill...thanks for sharing.

The stainless materials I'm using are: 
1) Throttle Rod- SS#416
2) Regulator Tube- SS#304
3) Regulator Tube Screws- SS#18-8 (300 Series)

I used the SS#416 for the control rod primarily because it is easier to machine and I'll need to cut a square section and threads on the end of the throttle control rods. For the other two it was primarily a matter of purchasing what was available from McMaster Carr for the tubing and miniature machine screw applications.

All three materials show good corrosion resistance to north of 1200 degrees, so I think I'll be OK for the internal parts of the boiler as temps are moderate and liquid is distilled water.

Now back in the old days when I was selling temperature probes to be used in molten aluminum...that was corrosive!....Moly based probes were lucky to last through a shift, and I had clients trying all sorts of exotic materials trying to get better tool life!


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## bille1906 (May 2, 2009)

Yea, It is strange about the stainless. I soldered some one day and left it in a mild solution of citric acid overnight and was surprised to find it corroded the next morning. I also has a stainless spring from McMaster rust in half on a whistle valve after about five years
If you go to McMaster and type in Stainless Steel and then "about Stainless..." you can see a chart which showa some of the alloys as not very resistant so now if there is a choice, I always go with the most resistant unless I am going to machine it then I use 303
Looking at the chart, the 416 may be a problem vs 303 which machines very well


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## BigRedOne (Dec 13, 2012)

How serviceable are these internal components, if for example a solder joint were to fail?

I've been looking through the "Model Boilermaking" book, and it seems a steam dome is preferred to taking steam from the top inside of the boiler, but wouldn't a turret at the rear be just as effective?

Thanks,
Matthew


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## clifforddward (Jan 2, 2008)

Matthew:
The problem with a steam turret is that by design typically several components are pulled off of it...such as whistle, water gauge, blower, and then maybe main steam supply...or some subset of that. What happens is when the whistle is blown, the steam pressure changes dramatically and the water gauge level is affected...or when the blower is turned on the water gauge no longer reads properly. Turrets are fine to use, just have to be careful what items are tied into it. 

That is why for this project we are moving to having the main steam takeoff occur in the steam dome on mid point of the boiler, the water gauge has it's own feeds directly to the boiler, and then the turret will be left for items not critical for pressure sensitivity.

Regarding any future failed solder joint...the entire regulator assembly will be removable so it can be replaced if there is some problem...or for maintenance, say for O-rings.


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## JimB (Jan 25, 2013)

Cliff, As you go along can you show how that valve is connected up and also the steam dome area. I've got some LBSC books and the internal valves look a little complicated tucked away inside. I like how it keeps the backhead clean without a bunch of fittings though, Thanks James


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## Phippsburg Eric (Jan 10, 2008)

I have used silver solder to join stainless part on a model sailboat. They looked great and were strong. However in salt water they came apart in a couple of seasons use. The silver solder was no longer stuck to the stainless. This seemed to be the result of corrosion. I do not know what species the stainless was, it was scrap I picked up somewhere. I would not use stainless and silver solder in any critical parts exposed to steam or boiler water.


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## clifforddward (Jan 2, 2008)

Thanks for the input Eric...will be interesting to see how things hold up over time in my regulator.


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## Steve Ciambrone (Feb 25, 2014)

Eric,
With the environment of salt water and dissimilar metals, galvanic corrosion was occurring. It will eat the less noble metal. With a boiler and distilled water any corrosion will be slower or nonexistent. It will be interesting to see the long term effects, if any.

Steve


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## BigRedOne (Dec 13, 2012)

Regarding the durability of the joint, it looks like a brass sleeve attaches to the rear of the regulator valve, and extends to the backhead? So, there isn't water surrounding the control rod?

Matthew


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## clifforddward (Jan 2, 2008)

Actually, while most LBSC designs used brass tubing, we are using SS tube for the sleeve you are referring to that connects the rear of the regulator body to the bronze flange at the backhead.

Having said that, yes you are correct, water is not surrounding the SS steam valve control rod extension...that's the plan at least...I think in the original design water did get in the assembly...that is the reason for the packing at the flange in the backhead. I have not decided if I will include an o-ring there or not...it would be a sort of "belt and suspenders" type of arrangement, but perhaps good insurance....I'm still thinking on it...


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## peterkalinowski (Feb 25, 2015)

*Drawings at last and well done*

I have only just come across your site today. I started design work on a Lawley after I met the CEO of Sandstone Estates when he visited the UK to present a locomotive for display at Lord Beaulieu's museum in 2006.

The engine is a Decauville 0-4-0 tank and VERY small. Mr Wilfred Mole (the CEO) promised to write to me with detailed dimensions of the Lawley that his team have preserved in SA. After repeated e-mails and waiting for 3 years with no luck I gave up.

However I did make a pattern for the wheels and had them cast in cast iron in anticipation.

Now you guys have found a GA drawing - well done you.!!! So I am restarting my engine thanks to your efforts.

Regards Peter Kalinowski


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## clifforddward (Jan 2, 2008)

Hi Peter:
Thank you for your posting...seems there are a number of people around the world interested in these South African Lawley locos.
I'd be interested to learn more about your driver wheel castings...first, are you modeling in 7/8" scale? If so, are the patterns in a place where more could be made? The several of us have drivers already, which are CNC machined parts, it would be interesting to see what your cast drivers look like to see how they compare...I would not be opposed to obtaining a couple of sets of cast drivers for my two Lawley locos if they represented an improvement. 
Send me a direct email offline and we'll start a conversation: [email protected]
And do post photos of your cast wheels here on this site...if you don't have photo hosting abilities send me a .jpg image of the wheels and I will host them and post to this thread.
Best Regards,
Cliff


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## clifforddward (Jan 2, 2008)

Sorry for the long delay since my lasting posting...it was a VERY busy January-March at work, and I did not get to enjoy much time in the workshop.

I've also been having a very difficult time sorting out the internal steam regulators I've been making for our team...readers will remember I was tasked with making the steam regulator assemblies for our entire build of four engines. In December I thought I had all the design work sorted out and it was going to be a simple production job to make the assemblies. Well, Mr. Murphy came to visit, and things went south...When I through bored the hole it kept wandered, which in turn kept the cone on the steam valve shaft from lining up....this made a good seal difficult. 

Over the course of the past several weeks I've refined my technique and several dimensions and finally got the regulator bodies worked out... 

In addition to the problems I was having making the regulator bodies, I also was not satisfied with the commercial brass cones on the steam valves I had purchased...as can be seen in the photos the brass tip is softer than the bronze regulator body and as a result the tip deformed when tightened down in the regulator body...in time I feared they would fail. Plus the soldered-on extensions seemed a bit "Mickey Mouse" to me after I looked at them a while.

So I decided to scrap the idea of using commercial steam cones, and made my own from stainless steel. An order for some tight tolerance 5mm 416SS from McMaster Carr this week and I was back in business....remade the steam valve shaft as a one piece unit (bottom shaft in the photos). It was tedious turning, but the new one-piece SS unit works perfectly!

Balance of this weekend I'll make up three more one-piece steam valve shafts and then remake two of the bronze steam regulator bodies I am not 100% satisfied with....but everything is now sorted and I feel confident this portion of steam control for the Lawley is figured out.

Oh, and BTW, steam seal for the shaft will move to the flange at blackhead, as per current Aster practice...should be an easy O-ring seal.

More to follow....


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## clifforddward (Jan 2, 2008)

Now that the steam regulator body/shaft assemblies are complete, time to tackle the rest of the steam regulator assembly...

Next up is the backhead area, specifically where the steam control shaft passes through the backhead to create the throttle for locomotive steam control. For most of the larger assemblies on the boiler we've decided to use flanged bushes, both to assure a good seal as well as create prototypical looking components. First is the flanged bush that will be silver soldered onto the backhead for the regulator assembly to pass through. Overall diameter of the regulator body is .435"...the flange will have an ID of .440", and utilize six 2-56 stainless steel studs for mounting.

The flanged bushes are a simple turning job, with special attention given to making four identical bushes. This is important so that secondary operations will work out the same for all four engines. As I've noted on previous occasions, making multiples of anything presents a challenge...for most of our activities it is only important that the parts we make mate to the one assembly it is being built for...making multiple of the same part requires more stringent standards to be applied.

Once the bronze bushes are turned up, next comes locating and drilling holes for the 2-56 studs. There are multiple methods of creating holes around a center point, but my preferred method for this sort of work is by utilizing a rotary table....I have several in different sizes and find they make easy repeatable results out of this often feared task. In the photos below I've shown how I drilled the stud holes on this flanged bush.

Here are the components of the rotary table for this operation...as is so often the case, the biggest part of any metalworking job is figuring out how to hold the item to be machined. Rotary tables have an indexing hole centrally located on the table...by machining up parts to fit this indexing hole it is possible to provide a means of indexing the machine spindle to the center of the work.








Here is a detail photo showing the parts that will provide the indexing:








And a couple of photos showing the Cameron Micro Drill press with indexing tools being used to line up the work to the spindle of the machine. These indexing jig tools are added to my box of Cameron drill press parts...over time I end up with an assortment of fixtures that are easily adapted to the next job to be worked on with the rotary table.
















In this next series of photos you can see where I have shifted the rotary table over to match the bolt circle for the flange. The rotary table is locked down for each drilling operation, then advanced the appropriate amount for the next hole. For this flange with 6 studs each hole is 60 degrees apart (360 degrees divided by 6 equals 60 degrees). Holes are drilled progressing from center drilling to final hole size drilling. In the case of this flange the final holes are made with a #50 drill bit to prepare for tapping the 2-56 threads for the ss studs to mount in. 

VERY IMPORTANT to successful small hole drilling is to always use a center drill when starting holes...here I am using a #1 center drill. Starting with a center drill assures the final holes with the twist drill bit will go straight and not wander.
























Stay tuned for our next operation...tapping these tiny holes without breaking the small 2-56 taps...using a hand tapping jig will make short work of this....


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## Kovacjr (Jan 2, 2008)

Cliff, Yes once you silversoldered the extension to the valve spindle you annealed the brass. Ive cranked pretty hard on these in the OE bodies and never have done that damage. Make a visible ring yes but never anything I can feel on my finger. Looks good. So will you have a completed boiler for June?


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## clifforddward (Jan 2, 2008)

I believe you are correct Jason...the brass on the valve spindles became annealed and proved worthless in the application...an unexpected side result of adding the extensions. No problem, however, as the SS spindle shaft with the integral cone tip is a more elegant solution...in the end all is well.

No, I don't think the boilers will be finished, but certainly the regulator assembly will be done, complete with all fittings for backhead, vertical takeoff for the steam dome and outlet with header to mount in the front tube plate. It's a pretty important component that is critical to long term performance and enjoyment...I want to get it right. Besides, between now and Steve's June meet I have Stapleton's steam-up and a local G1MRA meet to attend....gotta enjoy running my other trains while I'm building this one!


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## clifforddward (Jan 2, 2008)

When threading small holes like these 2-56 for the backhead flange studs, I use my hand threading machine whenever possible. This photo shows how it is set up for use...it is a rather simple jig, but one that assures the tap will not be tilted during threading. Not only does it help create better threads, the probability of breaking a tap is reduced to near zero. Over the course of the last decade I have yet to break a tap when using this device. They are readily available from any of the big box machining sources...mine is smaller than most which I like as my tapping is primarily small work. I encourage you to look for a smaller one as feel will be enhanced when tapping small holes. 








And a close-up of the threading...I'm tapping blind holes on these flanges, and the tapping machine makes it easy to have a sensitive touch when threading using a bottoming tap into the blind hole...you need to use a delicate touch so that when the tap hits the bottom of the hole you stop immediately or else risk stripping the threads.








Here is the finished flange with a piece of threaded 2-56 stainless and a small pattern nut. The Blind bottomed holes were drilled to be just short of breaking through the bottom of the flange. This will allow us to silver solder the flange to the boiler without having the solder flow up into the threaded portion of the flange. I'll wait to make the studs until after I make the mating flange so that the exact length can be determined...they won't be installed until after all silver solder work is complete on the boiler so that we don't introduce steel into the pickle solution. Note too the small pattern nuts in relation to the width of the flange...the flange will be just wider than the nuts, making for a nice appearance in the final installation.








Several have written and asked me to include something in my photos for size reference...Here I'm using a penny to give an idea of the small work involved...I'll try to remember to include size reference items moving forward...

On to the mating flange with it's seal for the steam valve shaft...


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## clifforddward (Jan 2, 2008)

Getting closer now...Here is tonight's progress with a view of the flange that goes at the backhead. Note the internal threads...at the bottom of the threaded hole there is a squared off front end where the O-ring will seal the steam valve shaft from the pressurized steam in the boiler.








Next will be making a jig to hold this flange in the rotary table so I can drill clearance holes for the studs on the flanged bush.

I'm into the easy, relaxing stuff now...enjoyable work at the lathe...


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## Kovacjr (Jan 2, 2008)

Looks good. And don't worry Cliff, You wont strip the threads. You'll just snap the tap hahah. Any of course it always snaps perfectly flush every time.


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## HampshireCountyNarrowGage (Apr 4, 2012)

Hey Cliff, how's the 4-4-0 coming along?


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## clifforddward (Jan 2, 2008)

Hi Chester:
Thanks for asking...finishing up the flanges for the regulator assembly now...summer holiday "duties" with the family have had me busy, but should be able to post some photos soon...
All the best,
Cliff


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## clifforddward (Jan 2, 2008)

Finally getting back on the Lawley regulators after a long break (how does that happen!?!)

Here in order to drill clearance holes in the flange end of the regulator end pieces, I needed to make a holding jig for the 1.25" body of the flange...here one sits in the jig with holes complete...first I drill one hole, screwing it to the jig, then drilling the remaining 5 for a total of six around the flange circumference. Screwing it down to the jig assures nothing moves and the rotary table makes short work of evenly spaced holes.


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## ArtificerJon (May 27, 2016)

Clifford, I have been trying for some considerable time to get hold of drawings of the Lawley NG6, preferably works originals, But from here in the UK I have had no luck, despite the full size locos being built at Brush Works Loughborough. Would it be possible to buy copies of what you are working from and have also produces ?


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## clifforddward (Jan 2, 2008)

Time to get the Lawley Regulators finished up....so after a long hiatus I dusted off the bench and am back at it....here are the four regulator assemblies with regulator flanges fitted to their mating flange that gets soldered to the boiler backhead. Stainless studs will replace the 2-56 machine screws that are currently shown...






Next I'll make up the plugs that screw into the end of the flange which in conjunction with the O ring create a seal for the backhead end of the regulator shaft...


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## Tomahawk & Western RR (Sep 22, 2015)

very nice!


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## clifforddward (Jan 2, 2008)

*Getting back to the bench....*

Amazing how seemingly small matters have major consequences....a program expansion at my "day" job resulted in nearly a 9 month hiatus from working on the Lawley....gotta keep that from happening again!

So I'm back at it....finishing up the various bushes and custom fittings necessary to solder on the boiler before I can finish that aspect of the project. Here I'm concentrating on getting one of two boilers finished so I can hand off to Jay Kovac at the ECLS show in a couple of weeks. Jay wanted in on the Lawley build group, so I traded him one of the two project engine parts I had...in the deal I agreed to finish up the boiler before turning that project engine over to him to work on...

Here i'm making the custom bushes and fittings related to installing the "in boiler" steam regulator into the boiler along with some other fittings...in usual fashion I draw out parts on 3x3 sticky notes and make alterations as needed. There are bushes related to a hollow boiler stay for transferring steam to the smokebox for the blower, a bush for the steam dome, and bush and fittings for getting the steam line through the front tube plate. 

One thing I've learned with this project is there are SO many more things to consider when placing the steam regulator inside the boiler...at first it seemed like a straightforward affair...now I realize there are at least twice as many parts to make to get everything working well.


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## Tom Bowdler (Jan 3, 2008)

Good to see you back at it Cliff,
watching with interest,
Tom


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## bille1906 (May 2, 2009)

Yes
I was wondering what happened to you
Keep it coming


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## clifforddward (Jan 2, 2008)

*Gun Drilling...*

The internal regulator has two steam lines requiring tubing...one leading from the front of the regulator to the front tube plate delivering steam for the cylinders, and the other leading from the top of the regulator up into the steam dome for pickup of steam. Since these will be in constant use inside the boiler, bronze is the material of choice to use. Unfortunately bronze pipe is not available in the needed 3/16" diameter, so what to do?....why make the pipe of course!

OK, I've got some 3/16" bronze rod, so simple enough, right?....but wait a minute, that #43 hole is .089" in diameter, and the bronze rod needing a through hole is 3 1/4" long....my question to self was "can it be done"? 

In the machining world drilling a hole to a depth of more than 10x the diameter is referred to as "Gun Drilling"....the process can be problematic as twist drill bits are quite flexible and there are probably a dozen things that can go wrong and cause the bit to wander off center....This application I'm working on is 37x the diameter...certainly be a good test of the lathe!

First I obtained a quality extra long #43 drill bit from McMaster Carr...and pulled out a fresh #0 center drill bit to start the hole. The bronze rod was held in a collet so it ran true. I'm also very finicky about alignment of my lathe's tailstock which means the tailstock chuck (a quality ball bearing Jacobs unit) can be relied upon to run straight.

So in the end with good tools, careful technique, and advance planning the task of gun drilling the bronze rod proved easy enough. Photos below show the lathe set-up and end results of the far end exit hole (I had turned around the part in the collet for the photo). The exit hole was very near center and certainly acceptable for this application. 

While I had the machine set up I made the tubes for all four regulators in the group build.


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## bille1906 (May 2, 2009)

Beautiful job Cliff
I am just curious why you didn't use copper or stainless tubing


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## clifforddward (Jan 2, 2008)

Good question Bill...as for copper I was concerned about cutting good threads for sealing that would stand up to repeated removal, and as for stainless I had no confidence I'd be able to drill that deep hole in a harder material without it wandering. Now that I have tubes that work, I should try drilling stainless to see if it works...I have some in 3/16" so would be easy enough to test...


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## Kovacjr (Jan 2, 2008)

clifforddward said:


> Good question Bill...as for copper I was concerned about cutting good threads for sealing that would stand up to repeated removal, and as for stainless I had no confidence I'd be able to drill that deep hole in a harder material without it wandering. Now that I have tubes that work, I should try drilling stainless to see if it works...I have some in 3/16" so would be easy enough to test...


Cliff what grade SS?? Don't waste the bit trying to drill it, you may snap. Bronze is perfect. Its inside the boiler anyway and should be copper or bronze. Dont want the issues you get on old Asters with the throttles locking up from the different rates of expansion of the steels vs coppers.


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## bille1906 (May 2, 2009)

Cliff
I was actually referring to SS tubing
I use 3/16" SS tubing for the superheaters on my larger engines and then use either brass or bronze ends threaded to suit but 303 ends could be used also. The thin wall tubing is about .150" id so I get good flow through it.


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## clifforddward (Jan 2, 2008)

Jay:
I forget which SS small rod I have...probably 304 or 316...in any case the Lawley regulator pieces are done, so they'll be bronze...also opens the option to easily silver solder the front steam tube to the regulator if you like since both pieces will be bronze...


Bill:
Thanks for the thought...SS tubing...certainly worth thinking about next time around...I'm modeling this regulator off a description in an old british loco builder book..I forget there are materials we can easily obtain now that were difficult or even unavailable to model engineers in days gone by...


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## clifforddward (Jan 2, 2008)

*Boiler front tube plate*

Closing in on completing the first boiler this weekend...here I'm soldering up the front tube plate.

Interesting how the more one silver solders the easier it gets...practicing technique is helpful, and with silver soldering cleanliness is everything. First time I soldered this many tubes in a boiler I was scared I'd get it wrong...the job today was pure joy. On the Lawley boiler this turns out to be a fairly straightforward job as there's not a lot of copper mass at the front tubeplate, just the boiler tube....this means it's easy enough to get everything up to temperature for the solder to flow. I did end up doing two heats (with solder bath in between) as I found a tiny pin sized depression by one tube that I wasn't certain was sealed...better to reheat now than worry later. So long as you lather up the surrounding area with flux reheats are fine and allow for adding additional solder where needed.

Here's the before and after photos:


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## bille1906 (May 2, 2009)

Looks great Cliff
I notice you have a ring around the large tube but not the others
I use 1/32" solder a lot. You can pick it up at most welding supply shops or they can order it for you. I then grab a rod the size of the tubes or a little smaller and wrap it around in a spiral the number of times for the tubes I have and then cut off the rings with dikes,
This helps in preventing the little pin holes around the tubes and is also great for soldering small pieces.


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## clifforddward (Jan 2, 2008)

Bill, you are right of course...when I did my K1 boiler I used 1/32" solder wrapped around each tube...it melted easily but still a tiny pinhole or two...actually the reason I'm using the 1/16" solder at this time is I came into about 12 pounds of the stuff a few years ago when I was looking for some silver solder with cadmium...so I've got gobs of it to use!


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## clifforddward (Jan 2, 2008)

*Lawley Boiler #1 completed!*

Voila!...a few last bits got soldered on and now the first Lawley boiler is completely finished. After a pickle in Sparex and a scrub with the Brillo pad it cleaned up nicely....photos here for those that have been following this journey:


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## placitassteam (Jan 2, 2008)

Very nice looking boiler! Maybe I missed it but what is a "lawley Boiler"?


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## clifforddward (Jan 2, 2008)

The name "Lawley" refers to the locomotive, not the boiler type...You'll have to go way back to the first post in this thread to get the background:
"Originally classified by the Beira as "F4" engines, they were later renovated and classified by the South African Railway as "NG6" engines. Also commonly referred to as "Lawley" locomotives, a name referring to the primary builder of the Beira Railway." 

Those of us involved in this build have adopted the term "Lawley" because....well, actually I don't remember why we chose this term rather than "Beira F4" or "South African NG"....but like all good nicknames, this one has stuck so we keep using it...


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## clifforddward (Jan 2, 2008)

*Regulator assembly complete!...*

Finished the first of four Regulator assemblies....the first one always take longer to sort out, the remaining three will be easy to finish up in the next week or two then I'll be ready to turn away from the boiler for a while....

Here's a series of photos showing the complete "in boiler" regulator assembly. There are detail photos earlier in this thread but several have asked for overall photos in order to get a better understanding of how this regulator goes together and does its magic pulling steam from high up in the steam dome. I think photos today in this and my next post regarding the steam dome will make everything clear.

Of particular new interest will be how the regular shaft at the backhead and the steam outlet line in the firebox are sealed....Hopefully the photos show this clearly enough...I'm using an O-Ring placed in compression inside the bushings that have been silver soldered on the boiler. (refer to earlier photos showing these bushings on the finished boiler) I'm also using a specially fabricated brass washer on top of the O-Ring so that the twisting motion of tightening the brass sealing fitting does not translate against the O-Ring and cause it to tear inside the bushing. This is a feature I learned by studying how various clamping points on my South Bend lathe tighten down...in that application it is to keep tightening bolts from digging into steel parts...I figured the same principle would apply here as well. In any event the use of this custom fabricated washer allows me to make it exactly the thickness needed to provide proper clamping of the O-Ring....and I can make another later if I determine I need more or less clamping effort. As point of reference the current washer thickness is about .130"


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## placitassteam (Jan 2, 2008)

Thanks Cliff, I probably read early on and then forgot. The washer on the O-ring looks like a great idea. I'll have to go back and look at your earlier posts and the drawings of the regulator.


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## Kovacjr (Jan 2, 2008)

Winn, the boiler is for the South African NG6 4-4-0, Go to page 1 for photos of the loco.


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## clifforddward (Jan 2, 2008)

*Steam Dome...*

Here's the final piece of the internal regulator family of parts....the steam dome on top of the boiler. I think this series of photos will be self explanatory, showing how the steam tube on top of the internal regulator goes up into the steam dome, picking up steam from a point nearly an inch above the top of the boiler...this is just as in full size prototype practice, and there are many references in old model engineer books applauding the use of this method. I know a number of Aster locos have a similar steam pick up, including my Castle engine which helped me finally understand how this system works.

For future internal regulators, I am certain I could make many parts of the regulator smaller...although sometimes smaller comes with geometrically more difficult clearance and sealing issues...so time will tell how this works and if I need to go smaller for future regulator assemblies.


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## clifforddward (Jan 2, 2008)

*Boiler testing...*

I had not had time to do a formal boiler test before presenting Jay's Lawley boiler to him...turns out there were a couple of pin holes needing attention that I had missed. So the boiler came back onto my workbench for correction. A quick session at the silver solder hearth fixed the holes. 

Before returning the boiler to Jason I performed a proper boiler test. Making up the custom plugs and flange plates proved to be the lion's share of the work to test the boiler. The first photo shows the various fittings and adapters I had to make up to seal up this unique boiler for testing.

Second photo shows the boiler test set up with hand pump in place...the boiler is filled completely with water, then the hand pump produces the required 2x operating pressure...in this case 120 lbs. There's no replacing this final test to assure all is OK with the boiler...

Final photo shows the proof is in the gauge reading...Now that this test is complete Jason can have confidence to fire up the boiler for years to come.


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## bille1906 (May 2, 2009)

Cliff
Beautiful finished product.
I keep going back through the thread and admiring your machining skills.


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