# Water Gauge Project



## clifforddward (Jan 2, 2008)

Following my failed experiment with the purchased water gauge on my 0-4-0 project engine, I've decided to take matters in my own hands and design a suitable water gauge system myself. Readers of my previous posts may remember I altered my RH Billy kit boiler to accept a commercial water gauge I had purchased...it seemed nice enough, with quality fittings and a blow down valve....problem was, the gauge glass was 4mm O.D., and operation proved to be nearly worthless at providing an accurate measurement of water level in the boiler. It would measure properly when I operated the blow down valve, but within 30 seconds of running it was inaccurate again. I even tried placing a fine diameter wire in the tube to cut down on the capillary action to no avail. Time then to resort to my favorite source of corrective solutions in these types of situations....that being my own workshop!

Not wanting to expend a lot of effort just for one water gauge, I have decided to design a system that can be the basis of a new commercial offering...something that would be easily adaptable and something I can build and supply to the hobby long term. (Hey, I've got to figure some way to pay for my next live steam purchase, right?!?)

I've never been particularly fond of the available commercial water gauges...the brass fittings and hardware associated with them seemed mighty big for the application. I want to use a 6mm O.D. water gauge tube in order to avoid internal capillary action issues relating to incorrect reading, but I want to minimize the size of the upper and lower fittings....basically I would like a 6mm dia tube using fittings the size of a typical commercial 5mm dia unit. Is this possible?...I think so...now off to the shop!

I decided to work from the inside out...meaning I'd start with the water gauge tube itself. Having bought in water gauge tubing from a variety of hobby sources, I quickly discovered there is no such thing as a "standard" 6mm dia glass tube....the samples I have range from 5.9 to 6.3mm. If I am going to build a smaller bodied water gauge I was going to need to locate consistently sized glass tubing. Add to this the need for the glass tubing to be borosilicate glass (to hold up to heat and vibration), and also I wanted it to have a red line fused into the glass for easy reading in use. Like so many things in our hobby, the answer came from the industrial commercial market...I located a laboratory glass supplier that provided high quality borosilicate with consistent diameter...a quick order and a few days later I had a box of 4' pieces sitting on my workbench. Of course it is not so easy to work with 4' glass tubes, so I cut the stock down to manageable 12" pieces, then heated each end to soften the cuts and make them more rugged for later handling. 

Next for the redline....this is an important feature to me...to explain for those not familar, having a thin line on the back of the water gauge tube allows one to easily determine the water level...this is because where there is water in the tube, the line appears much thicker when viewed from the front of the glass...this is due to refracting of the image through the water in the tube....a physics lesson would explain exactly how, but for our purposes it is only important to know it works. So some experimenting with varying widths of line on 6mm tubing and then some research online and I was able to come up with a source for ceramic line decals in red color. Why ceramic decals you ask?.....simply put, the ceramic red line decals when heated in a 1000 degree glass kiln are fused directly into the glass surface...making a rugged, permanent line that will not wear off and will show up well over time.

Here's a photo of the current state of things with the project...you can see the tubes in front have the redline decal applied:










I know it appears pretty simple...I won't go into all the detail of how long it took me to figure out how to get that thin red line to remain straight for the entire 12" length!....suffice to say there was a fair bit of "language" involved before it all worked out.

Next step in the coming weeks is to rent time on the kiln at a local art glass workshop where I hope to successfully fuse the ceramic decals to the surface of the glass...it will either work or I'll end up with a puddle of glass with funny red stuff in it!...

Once I have the glass all sorted I should end up with consistent diameter tubing to work from....then I'll then be able to move onto the actual design of the water gauge. I'll order in some o-rings while I'm waiting my turn at the kiln, and hope to be back here in a few weeks with details of machining up some water gauge hardware in the shop. 

Stay tuned!.....I'll post details here as I make progress...

Best Regards,
Cliff


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## spincaster (Mar 10, 2012)

Cliff, 

Are you going to sell just finished gauges or offer the glass also. Are your gauges going to include any cocks? I think there is a definite need for small quality commercial fittings with ME threads suitable for G1 models. I'll be watching this thread!


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## clifforddward (Jan 2, 2008)

Yes, my plan is to offer both complete water gauges and replacement gauge glass tubes....but that is still way down the line...first I'll need to build and test...I won't offer anything commercially until I'm 100% satisfied with function of the design.

As to fitting size, pending testing, my current plan is to use 1/4-40 ME threads on the water gauge fittings...we'll see how that works out. I think that will be the smallest practical size to maintain good function.


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## spincaster (Mar 10, 2012)

Got CNC, turret lathe or chucker? 6mm converts to about 236" Many years ago I had a couple of gauge glasses from Fyne Fort Fittings in the UK that were intended for gauge 1. I don't remember the glass OD but it seems smaller than 6mm. They did not have red line or blue line. I think the mounting bushes were 3/16"-40. Bigger glass reads better though.


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## JEFF RUNGE (Jan 2, 2008)

Cliff, my wife has a ceramic shop and does slumped glass and fused glass in her kilns. She said the glass will begin to distort at 1200f


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## SteveC (Jan 2, 2008)

Cliff

Just thought the following may be of some help with ideas.









Bob Sorenson - Scratch Built Nina - Water Gauge/Sight Glass - Page 107-114 (PDF 9.5MB)[/b]


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## clifforddward (Jan 2, 2008)

Jeff:

Yes, your wife is correct...ceramic decals need lower temperature on glass, as it deforms at temps below typical ceramic firing. Luckily I am in contact with an art glass studio and will be going there in the next few weeks to fuse the red lines on the glass tubes...using their computer controlled glass kilns.

Best Regards,
Cliff


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## bfwlds (Jul 30, 2013)

The problem with using water sight glasses in our scale models is the perennial problem of air bubbles giving false and dangerous indications of water level in the boiler. Using a level detection system which actually measures the water level in the boiler, such as used in the WLDS system, avoids any error in detecting when the water level IN THE BOILER reaches a low point where water has to be added. The water level can be determined without need to stop the train by observing the color of the LED indicator as the train goes by. A guarantee that the system is operating is assured by observing that the LED is either green or red. 

Best Regards, 
Bill


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## bfwlds (Jul 30, 2013)

To those who asked whether the WLDS system is still available, the answer is there are a small number left from the last production run. If you were considering purchasing, order now. 
Bill


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## Chris Scott (Jan 2, 2008)

Bill;
You and I have debated (af few time) the need for a two probe WLDS versus a timing loop to detect high water level or estimate sufficient water has been added via a timer as with your WLDS. It just dawned on me, with your vertical probes could it be modified to have an actual high level detection in addition to the low level detection? 

Chris Scott


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## Chris Scott (Jan 2, 2008)

Reading my own post confused me so let me try again. 

Bill Bill; 
You and I have debated (af few time) the need for a two probe WLDS to detect both low and high water level. Or your WDLS design; a single probe to detect low level water and a timer to control the pump and how long the pump runs adding water to the boiler. Experimentation to tune the timer and how long the pump should run to fill the boiler to a desired level. It just dawned on me, with your vertical probes could it be modified to to detect detect both low and high water level? Detecting the high level would trigger shutting off the electric water pump or control the axle pump bypass valve. 

Chris Scott


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## Linsane (Jul 31, 2013)

Cliff, 
Would you mind going into the details of how you finally got that thin red line to remain straight? It's driving me nuts lol. I work at a glass factory in Millville, New Jersey, and my job is to apply redline decals to 30 inch tubes of glass. My boss and I have been ripping our hair out for going on two years now, and if one of us doesn't figure it out soon, I'm afraid we may end up hurting each other, haha! If I could know what process you used to get your decals straight, maybe I could apply that principle at work and you'd be saving both my boss and I some serious arguments. I appreciate any directions or help you could give me!  

Linda


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## clifforddward (Jan 2, 2008)

Linda:
Send me a PM with your phone number so I can call you to discuss how I apply these....a bit difficult to describe....suffice to say it is one of those "steady hands, keen eye, and once you start, continue with conviction" type of actions. I'll be happy to discuss further with you at any time.
BTW, for those interested in an update on the project, I have located a glass studio where I can get access to kilns for fusing the ceramic decal...just need to arrange a time to make the 2 hour drive to do the work....hopefully within the next couple of weeks.
Best Regards,
Cliff


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## Jerry Barnes (Jan 2, 2008)

I just made a decal and put it on my water glass.


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## clifforddward (Jan 2, 2008)

Drove over today to the art glass studio...I arranged with the owners to rent time on their kiln in order to fuse the ceramic "red line" decals that I have applied to the Borosilicate Glass tubing. The photo below shows the set up just before the kiln got closed and the firing sequence started. There's a fairly precise profile that needs to be followed in order for the ceramic decal to be properly fused, but the tubing not distorted. At the end of the cycle the red line will be a permanent part of the class and not subject to being rubbed off.










I was able to have a long discussion with one of the kiln experts, and determined a method for me to be able to also add a white background to these tubes behind the red line....this was exciting news, as lined gauge glass with a white background has not been available for some time, and it makes viewing the water level very easy. I'll need to do some experimentation with mixing and airbrushing the necessary white ceramic paint, and then will involve an additional firing in the kiln, but at this point is does appear possible...may be a month or more before I have the results of that experiment, but I'll keep all informed as to progress.

Once the gauge glass is fully ready, it will be time to turn to the design of the water gauge itself....


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## Chris Scott (Jan 2, 2008)

I've found glass tube ID is also a problem. It varies as much as the OD. 

For Accucraft locomotives there are some fairly simple modifications that significantly improve the factory water gauge.

1. Banjo Bolt. Below the factory cross drilled holes drill a 2nd set the same dia. 90 degrees to the original holes. ~3-4mm below the original holes so not to weaken the bolt itself. I found this alone made a a major improvement. Even if you add a blow down valve at the base of the water gauge fixing the banjo bolt is really a requirement.

2. Check all of the passages ID. Bore out any you find smaller so all the passages are uniform. Use a fine increment drill set. I've found on older Accucraft locos the passages are not the same. You can enlarge them a little as well but VERY LITTLE. 

3. If you have to replace the glass and can't find the exact OD replacement, you can enlarge, A Little, the opening in the collar nut. 

4. Two O-rings work better than one. David Bailey supplies 4 o-rings (2 top/bottom) with his replacement water gauge. 

5. Advice from Cliff at Accucraft, because the glass will expand with heat, don't tighten the collar nut, only finger tighten it. The first time you raise steam the water gauge will leak. Carefully tighten the collar nuts only enough to stop the water leak - then stop. It's a really really big PITA when the glass breaks after it's newly installed.


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## Captain Dan (Feb 7, 2008)

Hi Chris,

Would you explain your point 1 about the banjo bolt? I lost something in the 'translation.'

Thanks,

Dan Fuller


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## Pete Thornton (Jan 2, 2008)

Banjo Bolt. Below the factory cross drilled holes drill a 2nd set the same dia. 90 degrees to the original holes. ~3-4mm below the original holes so not to weaken the bolt 
Be warned that I had a banjo bolt break without my touching it. They are not strong.


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## clifforddward (Jan 2, 2008)

I am happy to report the fusing of the red line ceramic decals was a complete success...all tubes survived the firing fully intact. 

Next step is for me to mask off and spray the white background "stripe" over the red line...the width of this white background will be approximately 1/4th the circumference of the tube...The ceramic paint comes in power form which has to be mixed with a glue like substance then thinned just enough to push it through my airbrush....I anticipate a "trial and error" process to get it right...

When these tubes are installed in the final water gauge it will make reading the red line much easier as the white background will create a stark contrast to the thin red line....making it easier to see where the water level is.

There is some risk with the firing of this white background "stripe"....the fusing temperature for the white ceramic paint is close to the annealing temperature of the borosilicate glass tubes. The process will require a careful and slow ramp up to the final temperature in order to avoid collapse of the tubes. The kiln owner is confident his computer controlled furnace is up to the task, although there are no guarantees....

Once the final firing is complete and if successful I'll post some close up photos to show the effect of the white background....gauge glass tubes with the white behind the line have not been available for some time in the market...it will be good to have them once again if I can pull this off!


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## Chris Scott (Jan 2, 2008)

Posted By clifforddward on 07 Jul 2013 09:25 AM 
Yes, my plan is to offer both complete water gauges and replacement gauge glass tubes....but that is still way down the line...first I'll need to build and test...I won't offer anything commercially until I'm 100% satisfied with function of the design.

As to fitting size, pending testing, my current plan is to use 1/4-40 ME threads on the water gauge fittings...we'll see how that works out. I think that will be the smallest practical size to maintain good function.




Will you offer fittings for Accucraft locos ?


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## clifforddward (Jan 2, 2008)

Chris...I'll be happy to expand the offerings to include metric thread water gauges (for locos such as Accucraft)...after all, the brass won't care if it is an ME or metric thread on the base pieces...







...Actually I think that is one of the easiest aspects of the design

...but first I want to prove out the overall design...starting with the method of holding and securing the glass tube which will be standardized on 6mm O.D. First I'll sort that out a production method with minimum sized sealing nuts on the upper and lower housings...I want to maximize the available height of the glass column...it needs to show from slightly above the crown sheet/firetube line to as high on the boiler as possible. Where the bushes are already mounted in the boiler the only answer is to extend the glass tube column within the gauge design. 

Next I can test to see if a blowdown will be required (hopefully not with the 6mm tubing), and finally I'll determine a few inlet/outlet standard offerings...1/4-40 ME for certain, and other ME and metric as needed.

Is there a standard size for Accucraft water gauge bushes already factory fitted?....one size or several? Never too early to consider what final offerings to make available!


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## Chris Scott (Jan 2, 2008)

Hope your water gauge has a bush and plug at the bottom providing a option to add a blow down if we think one is need on our particular loco. Photo below of David Bailey's replacement water gauge with a blow down for Accucraft locos. Are there more Accucraft locos than any other brand?


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## Chris Scott (Jan 2, 2008)

Posted By Captain Dan on 20 Aug 2013 01:39 PM 
Hi Chris,

Would you explain your point 1 about the banjo bolt? I lost something in the 'translation.'

Thanks,

Dan Fuller


Below an EXAMPLE of a banjo bolt - it is not an Accucraft banjo bolt. 

[/b]

The Accucraft Banjo Bolt will look slightly different. The factory Banjo Bolt has one pair of holes. The bolt below is modified to add a pair of holes bored at 90 degree orientation to the factory holes. *The second pair of holes should be the same diameter as the factory holes. *Most critical is the space between the two pair of holes. If the space is small it weakens the bolt and it can break. Even with good space between the holes if the bolt is tightened too much it can break. 



Soak the paper washer in oil so it is well saturated, using two washers can help. Tighten the bolt snug not tight. Raise steam, steam will leak from the bolt. Tighten it further just until the steam leak stops. You might have to re-tighten the banjo bolt the next time or two the loco is fired. If a leak persists repeat washer soak, etc. I've never tried it but maybe a very small amount of thread sealant on the paper washer. Personally I've not broken a banjo bolt after modified.


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## clifforddward (Jan 2, 2008)

Chris:

Thanks for the photo of the DJB water gauge for Accucraft Locos....nice looking gauge, and for logos like the Accucraft with its two burners side by side creating plenty of headspace above for steam his design seems fine for that boiler....I don't see water gauges on the DJB website, but if Paul still has them available you should just get his and be done with it.

The initial purpose of my exercise is to minimize WG fitting size and maximize amount of upper gauge glass showing...not to provide a duplicate of current offerings on the market. For the larger Accucraft boilers it seems there are already WG products available in the market...I don't intend to provide a duplicate. 

Providing a threaded tap for purchaser to add a blow down would be an easy thing to add...although again I want to minimize fitting size, so if needed would want to incorporate the blow down into the lower fitting. Just want to avoid the need if possible...initial experiments show it can be eliminated by using 6mm OD tubing.

Best Regards,
Cliff


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## clifforddward (Jan 2, 2008)

Chris, there is a key feature missing on your photo of the banjo bolt with two cross holes...the diameter of the bolt needs to be turned down in the area of the cross holes...in your example there is nothing to center the banjo fitting and it is possible for the fitting to shift sideways and cover the cross hole...perhaps that is the purpose of your two cross holes, to still allow flow even if the banjo fitting shifts. It would be better to turn down the diameter where the cross hole it, and leave a larger diameter to locate the banjo fitting. 

To show graphically what I mean, here is a photo of a banjo fitting I outlined the construciton of some time ago on the MyLargeScale.com:










Here you can see that the banjo bolt above the cross hole is left larger in diameter...this will center the banjo fitting shown on the right and provide for good flow...no need for two cross holes. I suppose flow would be increased by use of two cross holes, but in practical application I have not found more than one hole needed if the banjo bolt and fitting are made to the design shown here which has proved successful since the early days of the live steam hobby...Also with two cross holes the banjo fitting would need to be larger (taller)...I am always looking for ways to make things smaller, so would want to avoid the need for a bigger banjo fitting.

Full details of making the banjo fitting in the photo above can be found in the "Informative Threads" section...here is a link to the thread:

http://www.santacruzlumberco.com/MLS_PDFs/MakingBanjoFitting.pdf

While this example details installation of a steam whistle, the construction technique would be the same for any application needing a banjo fitting for steam take off.

Best Regards,
Cliff


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## clifforddward (Jan 2, 2008)

Took advantage of the long holiday weekend and worked on the water gauge tubes. After a good bit of experimentation I was able to apply the white ceramic paint with my Paasche airbrush...I used my "H" airbrush with the largest #5 tip...pretty difficult pushing the ceramic particles through the fine orifice at the tip...getting the mixture correct with the right amount of retardant and special solution to assist flow took a good bit of trial and error...if I had not been using these brushes for the past 40 years I'm sure it would have taken a good bit more error. But in the end everything worked OK, and I was able to get the ceramic paint to stick to the Borosilicate glass tubes. Interesting thing was, when the paint had dried, it was extremely fragile in the unfired state...a quick call to the art glass studio confirmed that this is a bothersome aspect of the ceramic paint...until fired it easily flakes off. I had originally planned to box up the tubes and save the 2 hour drive to the studio, but there was no way the ceramic paint would hold up to being shipped...so it was off in the Mini with the Mrs for an afternoon adventure hand delivering the tubes...They had a class which was tying up the kilns, so it was a few days before they were able to free up a kiln to fire my job. 

I'm happy to report the firing was a greater success than I had originally anticipated. Scrap rate was about 25% as a result of ceramic paint flaking during the hand delivery and during kiln temperature ramp...at the beginning of the project I anticipated only half of the tubes surviving in a usable state; as it turned out the success rate easily outpaced that figure so all in all I am very pleased with the outcome.

As can be seen in the photos the white background makes it very easy to see the water level with the thin red line appearing much thicker below the water line. I am posting two photos of the same tube, one with and one without use of flash...as you can see the water level is quite apparent regardless of the light condition:






















Next it is on to construction of the water gauge fittings...I've just about finished drawing out the design, so it's time to take the cover off the lathe and get to turning!


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