# Red Fiber Washers: Question and Request



## doublereefed (Jan 3, 2008)

Dear live steam illuminati,

The Question:
I need to seal some banjo type fittings. The basic banjo bolt through a round fitting with washers on both sides. The Aster method (at least the last time I built one) was to use hard and THIN fiber washers with a thin layer of sealant. The Merlin/Mamod/16mm method (last time I worked on them) seems to be to use a thicker fiber washer and go for some "squish" to get a good seal. 

Any preference? My banjos are long enough to accommodate either method. I am thinking I will get thicker washers wet, then install and tighten them down (reasonably). I'd like to avoid sealant.

The Request:
I can't find any M5x8 fiber washers anywhere for a reasonable quantity, price, or delivery date. Do any of you have a stash of 12 I could dip into? I will buy some that are inexpensive but not likely to get them until late December, upon which I could restock you.

Thanks!

-Richard


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## du-bousquetaire (Feb 14, 2011)

The real problem maker I found are the Accucraft Banjo fittings. The bolt does not have a square head which permits a fiber washer, but a conical one which can only split the washer. I had some bad leaks in the cab fittings on my T1 this summer and decided to do something about it. And the result was: A hard time making these fittings steam tight. 

The whole idea of banjo joints should be questioned by us live steam users: Although they are a convenient way to join two pipes or fittings (especially for the manufacturer), they offer a very tortuous path to the steam , which in turn cannot be beneficial for the locomotives output. 

If I had the mechanical expertise as a machinist I would try suprressing them altogether on at least one engine on the path which goes from the regulator to the cylinders, just to see the results which would be startling for sure. Many a great locomotive engeneer of the more recent history of the breed spent their life doing this on the real ones with spectacular results.


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## seadawg (Jan 2, 2008)

Richard, I have had success in the past using a dollar bill with a rotary leather punch to create the inside hole and scissors or an exacto knife to make the outside. And you can make a bunch out of a single dollar!

The last few Aster kits I've assembled have used the sealant at all banjo fitting joints.


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## Larry Green (Jan 2, 2008)

Richard, I realize you said you do not want to use sealant. That said, Loctite pipe sealant in the small white tube, applied minimally, does an excellent job and can be cleaned off easily if necessary.
With ornery fiber or copper washer joints, it has solved the leaking for me.

Larry


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## doublereefed (Jan 3, 2008)

With all of your comments, and taking a closer look, I am going to go with thin washers and sealant. I will report back.


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## Taperpin (Jan 6, 2008)

Richard,
3/16 fibre washers are very close to 5mm, I use a step drill to open them out 6to 10 at atime and then mount on a mandrel in lathe and turn down the outside to desired diameter.Dow Corning engine sealant for assembly[black]works well..

Gordon.


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## Chris Scott (Jan 2, 2008)

du-bousquetaire said:


> The real problem maker I found are the Accucraft Banjo fittings. The bolt does not have a square head which permits a fiber washer, but a conical one which can only split the washer. I had some bad leaks in the cab fittings on my T1 this summer and decided to do something about it. And the result was: A hard time making these fittings steam tight.
> 
> The whole idea of banjo joints should be questioned by us live steam users: Although they are a convenient way to join two pipes or fittings (especially for the manufacturer), they offer a very tortuous path to the steam , which in turn cannot be beneficial for the locomotives output.
> 
> If I had the mechanical expertise as a machinist I would try suprressing them altogether on at least one engine on the path which goes from the regulator to the cylinders, just to see the results which would be startling for sure. Many a great locomotive engeneer of the more recent history of the breed spent their life doing this on the real ones with spectacular results.



If the bolt was square, (assume you mean no conical shaft to head transition), typically with over tightening the head would snap off. Prompting much b****hing. Conical is good. 

If you're splitting washers for sure you're over tightening the bolt. And/or you're using a washer with a ID that is too small. If the washer will not fit over the conical and lay flat on the bolt shoulder the washer is too small, the wrong size. Been there done that. 

Proper size fiber washers are available from a number of sources; Accucraft, The Train Dept, etc.

To make washers (like from a dollar bill) these hole punches are one way. But you will still need to soak them in oil although the problem is the dollar washer even saturated with oil is not as thick as a fiber washer. Two of these can work, but that's twice as expensive. 









Replacing Banjo fittings; One or more, alone or in combination, coupling(s), elbow(s) and/or Tee fitting(s) you can replace some of the banjo fittings. Example, steam pressure gauge. But you may need a stop nut as well - like use on Accucraft's sight glass boiler fittings You can get these in metric from Jason,Train Dept. 
https://www.thetraindepartment.com/


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## Chris Scott (Jan 2, 2008)

Most of the time the problem with a fiber washer is installing it dry and tightening the bolt too tight. 

Best method;
1. Select the right size fiber washer; Washer ID ~= Bolt Conical/bolt head OD

2. Soak a fiber washer in steam oil over night. Install the washer; tighten bolt to just snug, no further. (DO NOT TIGHTEN LIKE A LUG NUT). (TIP; Keep a few fiber washers in a small container of steam oil - ready and waiting) 

3. Raise steam. When steam begins to escapes tighten the bolt just to the point that steam stop escaping - NO TIGHTER. DONE.

Using this method no sealant is needed. Sealant just makes a mess that has to be cleaned up later if/when you disassemble it.

Locomotives stored for a very long period (couple+ years) the washer will dry out and likely need replacement, sometimes not. A hot climate - Sahara, (?) - washer will dry out sooner.

Works for me. Good luck.


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## Chris Scott (Jan 2, 2008)

I hadn't thought of it before nor heard of anyone doing it but I suppose you might use an O-ring. It would have to be a thin/small dia one so it wouldn't limit the number of threads engaged. Danger would be the same, tighten too tight. Use the same install method for a fiber washer including a bit of stem oil.


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## doublereefed (Jan 3, 2008)

Chris, will this work with the thin/hard fiber washers? I have several in my toolkit... there are at least three types: copper, thin fiber, thick fiber.

The only engine I ever had with copper was an old Merlin. I couldn't get new copper washers to seal and went to red thick fiber.

The only other experience I have (as noted below) is with thin washers and sealant ala Aster method. In that case I would place the sealant and washer and then gently tighten. Then let it set up overnight, and then give it an additional rotation. The thought being that the sealant (bathtub caulk straight out of the Aster box) would set up like a rubber o-ring, and then slightly tightening would create a pressure seal as well.

Very interested in your soaked-in-oil method... if that works with the thin fiber washers I will give that a try first.

Best,

-Richard




Chris Scott said:


> Most of the time the problem with a fiber washer is installing it dry and tightening the bolt too tight.
> 
> Best method;
> 1. Select the right size fiber washer; Washer ID ~= Bolt Conical/bolt head OD
> ...


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## du-bousquetaire (Feb 14, 2011)

Thanks Chris: I have a good deal of punches handy which I use to make my fiber washers (and cylinder gaskets as well), and did soak them in oil for more than 24 hours but they did split, it would seem that the inside diameter wasn't right probably too tight which explains why this happened. Anyways I thank you for this info, and I know that you shouldn't over tighten them, as the brass threads can break.
The problem is solved now so this will be on the next leak... The T1 did beautifully on the Twerenbolds new track with ten on, including two J&Ms which are heavy beasts for over an hour andf a half (used up all the meth in the tank).


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## Larry Green (Jan 2, 2008)

A bit about fiber washers--there are two types of material--paper based and linen based. Thin paper material can chip/crack easily; heating the material with a light bulb before punching usually helps. The fabric-based fiber is more tolerant when working, but more expensive. The fiber washers I have experienced in our models appears to be the paper stuff. Again, I use a bit of Loctite pipe sealant on them with excellent results.

Larry


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## rbednarik (Jan 2, 2008)

It should be noted that Conical headed banjo bolts are designed not to need a fiber washer under the head. The conical head is designed to be a tapered and lapped in seat, done by tightening the banjo to the correct spec. 

It then self-laps into the banjo fitting and makes a steam tight seat. Of course some of the high temp sealant on the conical surface helps eliminate any irregularities in the seating surface. 

If the seating surface of either the banjo or the conical section of the bolt is damaged or otherwise compromised, the surfaces should be cleaned and trued up again. 

The bottom side of the banjo, where it meets the boiler (or whichever bushing) then the fiber (or other type of material) washer should be used of course. 

As an alternative to the fiber washers, Regner and others offer excellent copper crush washers that provide a heat resistant, reusable, steam tight seal. There are even some tri-fold style used in fuel systems that are available and work excellently. Belt and braces with a small smear of high temp sealant doesn't go amiss either. 

The high temp sealant Larry describes is not the usual RTV, but is more like high temperature pipe dope. Easy cleanup and does not make a mess when removing the parts. It holds up far better than RTV for this particular purpose since it is a thread sealer, not a silicone gasket maker.


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## Nick Jr (Jan 2, 2008)

I have used Permatex Hight Temperature Thread Sealant for thread fittings. Also have had success using it for banjo fittings. LG


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## StackTalk (May 16, 2014)

To sort of round things out . . .

Is there a number on the Loctite product being recommended, like 567 or 5113, or some such?

~ Joe


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## rbednarik (Jan 2, 2008)

This is the product in question:

Permatex high temp thread sealant


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## fkrutzke (Jan 24, 2008)

Ryan

That is the best material available. It is a Teflon (PTFE) mixed with cyanoacrylate. 

I first learned about this from Mike Cheney close to 20 years ago. At the time it was only available from Dynatex.

I still buy it from them in 1.69 OZ tubes. I use it a lot on aircraft maintenance too.

Dynatex link -- http://www.dynatexinc.com/product-catalog.asp?viewProduct=49486

Buy here -- https://www.finditparts.com/product...MIyqTguK7p1wIVg_hkCh1flA-SEAYYASABEgIpA_D_BwE

The Loctite material is the same thing but more expensive. The Dynatex tube is about $10 to $11 for 50 ML

Torry


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## clifforddward (Jan 2, 2008)

I wanted to correct a comment offered on this thread:

"The whole idea of banjo joints should be questioned by us live steam users: Although they are a convenient way to join two pipes or fittings (especially for the manufacturer), they offer a very tortuous path to the steam , which in turn cannot be beneficial for the locomotives output."

Steam does not have the same issues of flow that liquid does, therefore there should not be any concern over a "tortuous path". 

One of the benefits to the banjo fitting in my opinion is it is an easy, forgiving joint for hobby machinists to make, not subject to internal sealing depths to be met in order to accomplish a good seal. As others have noted, with use of a good gasket such as one made from a dollar bill, and/or the proper sealant, a banjo fitting is a solid reliable way to make a connection.


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## Larry Green (Jan 2, 2008)

My LS stuff is still packed away at the moment, since we recently moved and my shop is still getting organized. From going online, the small 6ml tube of 565 is good for 300F, and the 592 for 400F. Not sure which is in my toolbox, but it works fine.

Larry


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## Nick Jr (Jan 2, 2008)

The Permatex that I have been using is good for 300'F. I must be doing something right as I have had no issues with any of my repairs so far. LG


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## du-bousquetaire (Feb 14, 2011)

I beg to differ with Cliff, the last developments in steam locomotive technology were made by thermodynamists who claimed the exact opposite. They streamlined the interior passages of steam from regulator to the stack and nearly doubled the output of relatively small engines while cuting back the water and coal consumption by a goood third.
If it worked for Chapelon on the real mac Coy, why wouldn't it work for us in gauge one? He once claimed that with his treatment, a big boy usually rated at 8 000HP would attain 12 000 HP. And he usually was very conservative in his estimates, every result he obtained in his long career passed and confirmed his estimates...
And by the way the interior streamlining didn't just concearn the exhaust for which he is most famous. Clearly the next step would have been to mix the best US practices (integral cast frames, Franklin journal boxes, roller bearings, side control systems, tandem rods etc.) with the best European practices (better steam passages, exhaust, superheater elements,Compound working, reheating and even steamjackets and triple expansion) 

He was well on the way to develop this on his texas type three cylinder compound, but at the French governements request, all new development of steam locos by the SNCF was curtailed in 1949 due to extremly low price of oil. His texas was already being built, the frame had been obtained from General steel castings, but all was halted. It is comonly accepted here that the head of the SNCF Louis Armand very much engaged in electrification and the new 25 kv AC electrification research (ripped off the German Hollental line), just didn't want him to turn out another giantly powerful steam locomotive that would ridiculise his early AC electrics efforts. This is history and is also the reason nearly all of his other locomotives save the famous Pacifics were scrapped! No evidence left...


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## seadawg (Jan 2, 2008)

*Putting my money where my mouth is...*

Latest gasket (I know it's not for a banjo fitting but...):



















The rotary leather punch was too big for this gasket, so I just sharpened one end of some scrap 3mm pipe that I literally had laying on my workbench!

(For my current GN S2 project.)


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## seadawg (Jan 2, 2008)

*Copper crush washers*

Going off my memory, REGNER recommended using "Hylomar" to seal the banjo bolts even when using their crush washers. It's good stuff, a little harder to get and a bit more messy (alcohol cleanup). But it never dries out, and purportedly used by formula one racing industry. Never had a leak using the combination of the two, maybe even a bit of overkill.


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## doublereefed (Jan 3, 2008)

Here is my report:






Copper crush washers only work with sealant based on experience with this current project. Perfectly good solution, however I think I would use them in the situation where everything has been steam tight and working, and you are just replacing a pressure gauge fitting or something like that.

On this project, I have been trying to seal the backhead on this Brittania, and it has been several nights of "two steps forward, one step back". Having a blast actually. But in this case I have had to assemble and disassemble repeatedly as I chase the new leaks, often requiring the removal of a perfectly good assembly to get to a bad one. In this case I have been using fiber washers with oil. I don't soak them per se, but oil them up with steam oil then assemble the parts. I snug it all down, and then do a final snug at pressure with a bit of soapy solution to help reveal the leaks. Interestingly, I did all of his on air and still had a few wisps in hard to reach places. On steam, those fittings have tightened up perfectly. All of the banjos are 7mm hex head, and I lucked out by having a long reach 7mm socket. It has been invaluable in gently snugging things down, avoiding too much torque (and damaged fittings) and with far more precision than a mini adjustable wrench or spanner. 

I also repaired the water supply check valve (both the tender pump and axle pump run through a single boiler check.) Tonight I need to clean out the axle pump checks.

Summary, fiber washers with oil are working extremely well on this project.


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## Nick Jr (Jan 2, 2008)

doublerfeed: (sorry, spell check keeps changing my entry of your pen name). in response to your blanket statement about 'copper crush washers'. I have used them for years on cars, trucks and motorcycles and have never used an additional sealant. If torqued to the manufacturer specifications in my experience they don't leak. I will add that I have never used the same ones twice. Are you tightening them enough to allow the crush designed in the washer to take effect? LG
EDIT: As an afterthought, just maybe our little locomotives are just too small to really take advantage of the feature of the crushed washer.


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## doublereefed (Jan 3, 2008)

Nick, good critique, I indeed am not making a blanket statement on crush washers. I have had locos in the past with crush washers and they held a seal perfectly. On this project, my experience is that they are not a great solution. Related to your point as well, there aren't torque specifications for a G1 live steamer from a company that is no longer in business, so it requires the Eyeball Mk1 and in my case yielded unreliable results. The face on theses banjos and seats are not freshly machined surfaces either, which I would think would greatly increase success with a crush washer.


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## Nick Jr (Jan 2, 2008)

double, like you I would also lean on the cautious side when tightening any fitting on our loco's. Last thing you want to do is strip a boiler fitting. LG


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## placitassteam (Jan 2, 2008)

Just an aside. When I make gaskets from dollar bills, I do the holes by pushing a drill bit through the dollar into the hole in the mating part. The drill bit should be a few thousands smaller than the hole and use the shank end of the bit. It usually works best to punch all the holes and then cut the outside profile.


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## Nick Jr (Jan 2, 2008)

placitassteam, thank you, that seems to be better and more exact than what I have been doing. LG


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## doublereefed (Jan 3, 2008)

Placitasteam, many a locomotive has been repaired and put back on the track at Diamondhead and NSS (and elsewhere!) with dollar bill gaskets. It was rumored that the Aster crowd were using $100 bills, never confirmed...


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## du-bousquetaire (Feb 14, 2011)

I had the same routine of making new seals on the T1 s cab fittings and testing four or five times except that I wanted to do tests in steam to be sure of the results. Now the problem is solved. I use dish washing liquid and air on new engines though. Of course when you start doing this you never know how many times you will have to cool it off after a test and redo the leaking fitting; in this case it came out to 5 times.


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## Chris Scott (Jan 2, 2008)

Are the ultra thin copper washers (takes 3-4 copper = 1 fiber washer) really crush type? 

When Accucraft switched from fiber to copper Cliff hated the change what with calls for replacement bolts having over tightened breaking off the bolt head. "Why change when things were just find with the old ones."

Whether fiber, (rubber(?)) or real crush type or any with sealant they're meant to compensate for minor surface variances for a complete tight seal. The copper washers I've handled are too thin to be crushable; why a sealant would be required lest it be over tightened and/or overtightened. I've a personal aversion to gum-up a joint with sealant and an oil soaked fiber washer works. Maybe if I could get a sealant in a different color than white?

I've not bought a loco that has copper washers so no hands on experience on impressions. That may be about to change as I have an Accucraft Bagnal coming. About, meaning if Accucraft UK uses copper or still fiber.


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## Chris Scott (Jan 2, 2008)

Ryan;
All of my Accucraft locomotives are in storage until summer so I can't check but I'm pretty sure all their loco's I've had/have had fiber washers at the top and bottom of banjo fittings. A close look at previous factory photos of cab plumbing seem to show a washer at the top.

I've always used a fresh oil soaked fiber washer anytime I opened a banjo fitting or wherever there was a factory installed fiber washer and tightened the bolt twice (cold and w/steam) as I described above. 

Accucraft's banjo female half is not tapered at either end on the inside to match the conical bolt. 

Are Aster's banjos tapered?


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## Chris Scott (Jan 2, 2008)

FYI; RC machine dealers carry a lot of different types and sizes of washers/gaskets if you want a wide diversity of choices.


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## clifforddward (Jan 2, 2008)

I tend to agree with Chris and his comments about red fiber gaskets...they have always been my "go to" of choice when making a banjo fitting...outlined in this article in the sticky threads section:
http://www.santacruzlumberco.com/MLS_PDFs/MakingBanjoFitting.pdf

Use of oil soaked red fiber gaskets work very well for joints that are typically not opened after construction. Note in the example thread on the goodall bolt I used an o-ring as that bolt is periodically loosened to service the silicone tubing on the goodall seal.

I've found copper washers work very well and can come in thinner and smaller sections for smaller installations...but the joint is less forgiving and must be machined more accurately.

If it ain't broke don't fix it.


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## du-bousquetaire (Feb 14, 2011)

I don't know if this is standard practice at Accucraft but the head of the bolt part of the banjo joint (I mean the part that screws in and closes the joint) is cone shaped on the PRR T1. It will split a fiber washer when you tighten it... I guess someone at the Accucraft plant thought he could make such a joint steam tight... It may have just been an experiment. You don't have this problem on Aster Banjos.


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## doublereefed (Jan 3, 2008)

Or, just wondering, would a cone shape with a copper washer be what they were going for? It wouldn't split copper...


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## SalM (Jan 2, 2008)

*Red Fiber Washers*

A lot of dodging of the original thread. Some time ago I asked MS. Flower of Wuhu for some assorted 

red fiber washers used on their engines. A few weeks later I had them.

I bet Jason with his link to Accucraft could sell a small zip lock bag of assorted washers used

on Accucraft steam trains . I would buy a few bags myself.

Obviously there is a need going unsatisfied.

Bet if they were on the table at DH bet they would disappear in a moment.


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## Chris Scott (Jan 2, 2008)

Sal;
A number of other live steam parts suppliers and general sources do sell fiber washers by individual sizes and misc sizes bags of washers.

Ministeam
https://www.ministeam.com/cgi-bin/sh000001.pl?WD=washers&PN=Set-of-washers-M3-M6-WI_01520%2ehtml#SID=245

eBay
https://www.ebay.co.uk/sch/i.html?_...washers.TRS0&_nkw=live+steam+washers&_sacat=0

POLLY MODEL ENGINEERING: Catalog page 49
http://www.pollymodelengineering.co.uk/sections/bruce-engineering/docs/Catalogue-may-2017.pdf

McMaster-Carr
https://www.mcmaster.com/#fiber-washers/=1aqpfe2

Amazon
https://www.amazon.com/dp/B01DBBV40Y/ref=asc_df_B01DBBV40Y5306440/?tag=hyprod-20&creative=395033&creativeASIN=B01DBBV40Y&linkCode=df0&hvadid=198062151020&hvpos=1o9&hvnetw=g&hvrand=11618391490555848503&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9032361&hvtargid=pla-320493119705


Google Search: Fiber Washers
https://www.google.com/search?q=fiber+washers&rlz=1C1CHFX_enUS697US697&oq=fiber+washers&aqs=chrome..69i57j69i60l3j0l2.4451j0j4&sourceid=chrome&ie=UTF-8


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## Kovacjr (Jan 2, 2008)

My Green gaskets were punched for me custom. In good gasket material. Its a shame I cant get the same guy to make more and I'm just about out. 

The copper washers that I used from Regner are concave and are a true crush washer. I have used for 10+ and have sold for many years since starting the business the Permatex Hitemp sealant. White non-hardening stuff.


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## rbednarik (Jan 2, 2008)

Again, The conical headed banjo bolts do not need a washer under the head. The banjo fitting to boiler connection should have a washer of choice. The banjo fitting itself (not the bolt) can be a square seat and work fine. Think about the geometry and you'll see it works. Or don't, either way it makes no difference here as we see plenty of them service through on all sorts of banjo fittings without incident. 

The conical head is much like the tapered end of a throttle valve, which on most backhead throttles, goes into a square seat. Last I checked this does not require a washer to seal properly when you close the throttle...

As for flat vs tapered banjo bolts, both Aster and Accucraft have used them in different ways over the various productions. 

Aster generally go with a flat banjo using a concentric locating step (like a hubcentric ring on a car wheel) that centers the banjo bolt in the fitting. However they have used tapered banjos in the past and those also have a washer or sealer on the boiler side ONLY. Works fine so long as you make sure the bolt is nipped up properly. 

Accucraft uses both interchangebly. Knowing when to use a washer and when not to is important. When in doubt, the high temp sealant will not make a mess of anything and cleans up to near invisible. 

Caveat to the sealant is that, the sealer is only effective if the installer takes the time to clean up the squeeze out and resists slathering it all over the joint in the first place. On a tapered (or flat) bolt a little bead about 1/16" long on the mating surface will travel the entire circumference as you tighten the bolt and provide the "belt and suspenders" seal that resists heat, overfiring, overheating, general use, etc. A little goes a long way. 

As Jay says above: The Regner copper washers are certainly crushable. They start out as a saucer shape and can be flattened out, distorting and forming to the mating surfaces in the process. Last I checked, that forms the bacis definition of a "Crush Washer" They may not be the tri-fold ones we see in the automotive world (although they do exist) but they serve the purpose well here. 

The Accucraft "copper" washers spoken of were nothing of the sort. There were aluminum and teflon washers, never copper. Both were inferior and hard to keep the fittings secure as they slipped all over. No positive feel when tightening. 

As always, individual mileage may vary, in this case more than opinions. 

There is nothing wrong with fiber washers, but they have a finite lifespan and degrade from heat, etc. Personally, I wouldn't want to rebuild a superheater hot side header with fiber washers, even if made from steam rated aramid paper.


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## clifforddward (Jan 2, 2008)

Well put Ryan


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## du-bousquetaire (Feb 14, 2011)

That is just what I did to solve the problem Ryan I made a fiber washer for the bottom of the outer banjo fitting (between it and the flange on the boiler) and used silicon on the conical part, just a tiny fillet around the cone which I cleaned up after tightening. That cured the problem well. At Railexpo the engine hauled Ten coaches including two heavy J & M for over an hour and aa half.
Any ways thanks for sharing your expertise on the matter with us all. And best wishes for Christmas and the new year.


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## Greg Elmassian (Jan 3, 2008)

This is most definitely the most detailed and in-depth thread on washers I have ever read, 5 pages!

Fun reading it, and learned something.

Greg


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## Chris Scott (Jan 2, 2008)

This is one of those great minds can differ situations. The photos below are a few examples of Banjo fittings using fiber washers at the top and bottom of the fitting. These great minds include:

DJB Model Engineering Ltd (David & Graham Bailey)
Berry Hill Works (Steve & Matt Action)
Accucraft
Roundhouse


All of the fiber washers in the photo appear to be installed dry (vs oil saturated.) If the fiber washer cracks or breaks when installed it's due to over tightening and or it's old and dried out. Soaking in oil overcomes this. Soaked in oil install tightened just to snug. Raise steam and when steam escapes from the joint tighten the bolt just to the point that steam stops leaking. One of Kevin O'Connor's tips years ago. 

Limited life span of fiber washers? I've owned and experienced quite old locomotives with fiber washers were the washers were perfectly fine. No leaks or cracks. So this is another case of experience differing without being conclusive on either side. I believe fiber washers have been used in steam locomotives and other similar toys for eons so they've carried us this far.

In my experience a Banjo fitting without a washer atop can leak under pressure. Possibly not at 50-60psi - nominal operating pressure - but hit ~80psi and it leaks. If a fiber washer works why change? 

The conical taper to me seems there to aid in centering bolt in the banjo and that's all. As far as the taper providing a seal with the banjo, WADR to Accucraft, they are not know for that fine level of engineering their locomotive fittings. A fiber (copper now) washer fits their business model, utility over fine precision. Aster would be the latter.

When Accucraft switched to copper washers the calls for replacement bolts plagued Cliff, customer’s having broken a bolt head off from over tightening. Cliff would coach them on tightening copper washers and suggest using a fiber washer instead. 

As to the theory that great minds can differ I make no claim for myself. I'm much too humble to make such a claim.   

Photos:
DJB WOTO Whistle; The situation which 
https://scontent-atl3-1.xx.fbcdn.ne...=f0bf358164222ece30d0abae1835b25b&oe=5AD2860F
https://scontent-atl3-1.xx.fbcdn.ne...=bfa328a89d38748f362048a34ffc2b66&oe=5ACC4173
https://scontent-atl3-1.xx.fbcdn.ne...=853fa8846e641caaa0fdba92314e7cee&oe=5AB23C52

Accucraft Jedrigs
https://scontent-atl3-1.xx.fbcdn.ne...=7b5d3b3c92d3cecc02957808044e40e8&oe=5ABF140A

DJB R/C whistle Roundhouse Sandy river No 24
https://scontent-atl3-1.xx.fbcdn.ne...=fa1d2edc3930f7365573410016c84cbe&oe=5AC0F8B1

Roundhouse Darjeeling D Class Garratt 
http://akubilr.asablo.jp/blog/img/2015/11/29/3e145d.jpg

Accucraft 0-4-0T Decauville fitted with a whistle (Fiber Washer and appears to Permatex/sealant on 2 joints of 3)
https://scontent-atl3-1.xx.fbcdn.ne...=203103ea590f0dd232bf582dd0fbee7f&oe=5ABE9295
2nd View
https://scontent-atl3-1.xx.fbcdn.ne...=e450b0b660d0f86c57970b0ac9f3c433&oe=5AC690C6

DBJ custom whistle for the Garden Rail 7/8ths Jack
https://scontent-atl3-1.xx.fbcdn.ne...=cf0c1ac7a3a75ff47e812ccfa59584d3&oe=5ABCC811
https://scontent-atl3-1.xx.fbcdn.ne...=4e58cc635b8e1c90902f492c77755d81&oe=5ACD1034

Coal fired RTR Cedrig
https://scontent-atl3-1.xx.fbcdn.ne...=43b6d81cb7ef263c69a5e9538b5834d6&oe=5ACD277D


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## rbednarik (Jan 2, 2008)

All of those examples shown are non conical (read tapered) headed banjo bolts. The use of a washer on either side or some sort of sealer (or both if needed) is warranted on flat banjo connections. I never said anything to the contrary. 

The taper is mostly sealing although it does have the added effect of centering the banjo fitting. However, if trying to use a fiber washer under the tapered end, you will most certainly split it if the bolt is tightened down to spec.

Torque value for bolts is something learned by feel, and certainly one way to learn it is to break bolts. It could be argued that the better way is to learn when it is snug under a steam test. Compressable washers help give indications when the joint is sealed and not stressing the bolt. 

All seals have finite life, even fiber washers made from unobtanium and tightened expertly with a left handed monkey wrench.


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## Chris Scott (Jan 2, 2008)

rbednarik said:


> All of those examples shown are non conical (read tapered) headed banjo bolts. The use of a washer on either side or some sort of sealer (or both if needed) is warranted on flat banjo connections. I never said anything to the contrary.
> 
> The taper is mostly sealing although it does have the added effect of centering the banjo fitting. However, if trying to use a fiber washer under the tapered end, you will most certainly split it if the bolt is tightened down to spec.
> 
> ...


How is that you know all of them are non-conical? I did include some that are not. 

If a bolt's conical seals against the banjo why is there free play between the bolt and the banjo when the two are assembled correctly in one's hand?

Split Fiber Washer:
The fiber washer will split if the ID of the fiber washer is less than the OD of the banjo bolt taper at the bolt head. The fiber washers that Accucraft factory installs and I use as replacements, the ID is the same as the OD of the conical bolt at the bolt head and why they do not split. This is a strange idea that one would assemble a fitting with a washer, fiber or any other, where the washer isn't the right size and suggest that is the failure of the washer when in fact the failure was choosing the wrong washer. Another way to tell you've chosen the wrong size, too small ID, washer would be to compare Accucraft's installed banjo bolt head washer to the washer you picked that split. They obviously would not match ID to ID. Another check for the correct washer would be to slip the washer up the bolt toward the conical encountering the problem of the washer not being of sufficient ID size to slide over the conical all the way to the top underside of the banjo bolt. 

It's like ordering the fish entre and saying it isn't steak. It isn't steak because you failed to choose steak you chose the wrong entre. It's not the fishes nor the steak fault. If you have a medical condition that cause your wrong choices well, that is too bad. But that just means you didn't ask anyone for help or use an objective means of determining the fish is a fish not steak. For example, steak does not have scales or fins. 

In the case of choosing the wrong washer using a instrument such as a caliper instead of guessing would have helped your washer choice. That is as long as you measured the conical at the bolt head and not the shank of the bolt. Washers of the proper size are very common, widely available and very inexpensive.

It is a bit of a long explanation but that's inevitably what happens when someone throws in a left handed monkey wrench made of cuteium. 

I know you'll have a last word but this really has become tedious. I know you are happy with your washer choices which is all that really matters. Good luck and God bless.


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## Kovacjr (Jan 2, 2008)

Jeez Chris what is it about every subject you need to have a encyclopedia answer? 

BTW, not a single link of images are anything but a top and bottom washer type seal. All Paul/DJB uses is a flat surface with a washer. Roundhouse uses mostly annealed copper washers on the large boiler banjos and the red fiber washer on the throttle housing. Also note the copper is a single use, and recommended to replace when you take it apart. Ill always use a dab of the permatex as a backup. 

Accucraft has not used the tapered banjos for a very long time, well on 10 years. No washer was EVER used on the top of the banjo at the bolt at the taper is what made the seal. It deformed the hard edge of the banjo or fitting to the taper of the head. C21 somes to mine as does the K27 I think. My K28 is square fittings and washers on top and bottom. All newer were fiver with the exception when Trevor from G1MRCO asked Bing to change to a Teflon washer, that lasted a short time and was never used again due to high failures from heat.. At one time flat alum washes were tried but they did not seal well and Bing has always told me he cannot get a copper crush washer like the ones I supplied to him to compare from Regner..

This is what a tapered head bolt looks like. Maybe you have a different idea in your head what a tapered banjo bolt is but this is a stock Ruby throttle bolt. This is my 10-12 year old Ruby kit. It works just fine when used properly.


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## StackTalk (May 16, 2014)

In an effort to try and be helpful, I searched online for some time trying to find drawings of banjo fittings employing a tapered or conical banjo bolt assembly. I came up dry. Jason's photo of the old Ruby seems pretty clear though.

There are many drawings online of flat-shouldered banjo fittings including recessed flat-shouldered fittings where gaskets are used, generally made of copper when used for hydraulics or in the automotive industry. 

Aside: The SU fuel pump on my Austin Healey uses a resin washer whereas the brake and other fuel delivery components use copper washers and in some cases, paper fiber washers. There are no conical or tapered banjo bolts evident anywhere.

I suspect tapered or conical banjo bolts have long been out of favor?

Aster uses flat fittings and flat-shouldered bolts sometimes with a recess on the outer side of the fitting matching the bolt geometry so as to aid in positioning. Within the ten or so Aster assembly drawings that I have used or reviewed, _gaskets are not used at all_ for most banjo fittings, including for the axle pump, backhead and inside the smokebox. Aster instructs the assembler to simply apply a thin film of sealant. 

I assume that, the more precise the fit, the less likely a leak will result. I'm guessing that, especially for a loose or imprecise fit, a fiber washer may be helpful. 

A couple of years ago, Ryan revealed one of TRS's secrets in that they use copper crush washers along with a very sparing use of sealant even for Aster assembly . . . as a "belt and suspenders" approach. When clearances allow, I have adopted this approach when I have to take a fitting apart for any reason.

Edit: I'm sure Ryan will correct me if my memory is inaccurate.


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## Kovacjr (Jan 2, 2008)

Part of the reason for no washer but a sealant on the axlepumps, is the washer varies in thickness and the banjo is also the check valve. So if its too tight or too loose then the ball movement is altered. Not a problem when building from a new kit, but if you don't have that thickness washer to reassemble then it can change. I know when I am making a banjo fitting for a check on a pump, I add in the height difference of 2 copper washers but I always use flat bolts. Even if there is a slight relief on them at the neck which I always do for fitment, they are always a flat mating surface. 

O well, 5 pages of washer talk. HAHAHA


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## StackTalk (May 16, 2014)

Kovacjr said:


> *Part of the reason for no washer but a sealant on the axlepumps, is the washer varies in thickness and the banjo is also the check valve.* So if its too tight or too loose then the ball movement is altered. Not a problem when building from a new kit, but if you don't have that thickness washer to reassemble then it can change. I know when I am making a banjo fitting for a check on a pump, I add in the height difference of 2 copper washers but I always use flat bolts. Even if there is a slight relief on them at the neck which I always do for fitment, they are always a flat mating surface.
> 
> O well, 5 pages of washer talk. HAHAHA


Point well made and duly noted Jason.

Thank you.

~ Joe


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## rbednarik (Jan 2, 2008)

With some exception in this thread, the examples shown have been speculative opinion instead of fact. If I may be so bold as to sully all the elevated minds in this think tank with some more sorted things like actual factual evidence, please consider the following: 

For starters, if I may be so bold as to point out the reason a banjo fitting in one's hand would still be loose is that there is a slightly important third element to the basic assembly. The part the banjo bolt screws into (boiler bushing, turret, pump body, block, etc) is vital to actually making the connection work. I would have thought this may have been stating the obvious, but then again, what do I know. 

Now to the gritty-nitty: For reference, the below are some Aster engines using tapered banjo bolts. Some o these are 30+ years old, others are fairly recent. Note no washers or sealant call outs (the arrows) on the tapered side. there are other drawings that call for sealant on the taper side, but it is not consistent enough to claim standardization. 









































Sealer is not a bad idea, however on both the threads and banjo fittings for some of these. Especially those through pipes that carry the blower steam from the turret. Without some thread sealer, inevitably there is a chance boiler steam will go direct to the blower nozzle from the bushing where the through pipe is. 


This is followed by some examples of accucraft tapered banjos. Used not only on direct boiler feed fittings, but also axle pumps. Notice the lack washer on the tapered side. Sealer may be needed, but a washer certainly not.


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## Larry Green (Jan 2, 2008)

Perhaps something so small has become the center of a too-long debate? I have, in my ignorance, just muddled along with my supply of fiber and flat copper washers from RH and Regner, and my trusty little tube of Loctite thread sealant. Just my $0.02.

Larry


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