# Sight Glass Proplems



## HampshireCountyNarrowGage (Apr 4, 2012)

This past week end, Harvey Campbell and I ran our live steamers at the Fairfield Museum in Fairfield, CT for their annual Christmas train show. The kids loved it and so did some of the parents. But that's not why I'm writting.

I have an Accucraft 4-4-0 and the sight glass is really becoming frustrating. The only time it showed any kind of accuracy is at the first filling of the boiler. I think it was because of all the vibration the locomotive recieved on its trip to the museum that it shook the water into the same level as what was in the boiler. After the first fire up no more reliability of any kind. Either competely full or completely empty and every where in between.

Now I know there has been a lot written about this problem and I know it is an inherent problem due to the size of the glass tubing and the capillary action of the water. As I watched this problem all week end, I noticed that it was bubblies in the tube that was causing the problem. Big bubblies. And most of them came from the bottom elbow assembly of the glass. The bubble could not get to the top of the glass. I figure this is because of the pressure in the boiler. Yes?

I have not taken the sight glass assembly apart, yet. And before I do there are a couple of questions I'd like to ask. The first is to all 4-4-0 owners. Do you have this same problem and how are you handling it? Second. When the glass tube is inserted into the bottom elbow, how far into it is it placed? Meaning, does it get pushed all the way in until it touches bottom in the elbow or does it get placed in a measured amount so as not to block the water passage? I have read of placing a piece of wire inside the glass tubing to help break up the capillary action of the water. Does this help? Should the wire be lose so it vibrates? Should I replace the elbow fittings so that a larger glass tube can be used? Or should I just grit and bear it all?

It's been written that the locomotive is designed to run out of gas before the water, but with this sight glass problem I haven't been able to prove it one way or the other.

Thanks for taking the time to read this. Any help will be appreciated.


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## Nick Jr (Jan 2, 2008)

Chester, I don't have a 4-4-0 but do have several other LS locomotives. Many of us here have tried many 'easy' remedies and none seem to have worked as I'm sure you have seen. The wire in the site glass, most popular is great when the loco is cold, but warm it up and same thing happens. There was a gentleman, sorry I forgot who, posted he was working on a solution, but no more has been said since then that I am aware of. 
The closest to accurate one I own is the Roundhouse Mountaineer which is a bit different than any others I've seen anywhere.


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## clifforddward (Jan 2, 2008)

Hi Chester:

Yes, you have chanced upon an age old problem that many of us have encountered over the years....how to get the water gauge on our live steam locomotives to read correctly....

As most everybody points out, the problem seems related to the small ID of the glass tube in our garden sized locomotives. Certainly for the larger ride on locomotives it is less of a problem. Capillary action seems to be the largest contributing factor...having a water gauge with a "blowdown" will clear the bubbles and provide an accurate reading, but usually the problem comes back after a short while.

The "fine-wire-in-tube" does provide some relief, although as others have said it is less effective when the water gets hot.

I've been doing a detailed investigation of this problem off and on for the past couple of years....I think the key to reliable water gauge function is increasing the entire water path. This means making a water gauge with not only a larger diameter glass tube, but also increasing the size of the inlet and outlet fittings. For what it's worth I consider 6mm OD glass tube to be the minimum acceptable for ongoing reliable operation....I know this will hurt scale appearance on the backhead, but after surveying many owners with all types of live steam models, this is the conclusion I have come to.

With regard to the upper and lower fittings, take a look at the photo below for a comparison between a "typical" aftermarket water gauge (the one in red) and one made by Mike Chaney for his Catatonk Climax.....both use the same 5mm-5.5mm OD gauge glass, but the ID of the Chaney fitting is MUCH larger....probably 4x the cross section of water flow. This fitting is part of an assembly with no blowdown, yet it never experienced problems reading the proper level.








For the water gauge I am designing for my own use (and maybe sale later to others), I am using 6mm borosilicate glass with approximate ID of 4mm, and am making built up fittings top and bottom with internal passageways that are also about 4mm as well. I anticipate good water flow...testing will determine if this will work satisfactorily.

Speaking of blowdowns, I'm going to ruffle a few feathers and say that I think that while a blowdown on a water gauge can be helpful for any size gauge, where larger ID glass tube is used, and where the fittings have larger ID passageways, I don't think a blowdown will be needed for good function....we'll see if I am correct once I get adequate testing complete.


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## Pete Thornton (Jan 2, 2008)

> I don't think a blowdown will be needed


Cliff,
Your comment reminded me that older full size locos had a set of water taps to test the water level in the boiler. Like these on the right, opposite side from the sight glass.










Couldn't we install 'blowdowns' at two levels - one just above the flue and one higher up, with a very small capacity, so you either get a little plume of steam or a drip of water when you open it?


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## Semper Vaporo (Jan 2, 2008)

In real 1:1 practice it took a lot of experience to tell the water level using trycocks on the boiler backhead.

The water and the steam are both actually at the same pressure and are at a higher temperature than that necessary to turn to steam at normal pressure. When you open a trycock that is above the water level you get a rush of steam, but when you open the trycock that is below the water level, the water being released to the lower pressure of the atmosphere, instantly flashes to steam. So, both ways, you get steam, not liquid.

Telling the difference is more a matter of the sound of the venting H2O and takes experience to tell if it is just steam escaping or water flashing to steam.

Many inexperienced hostlers that were watching a locomotive, like overnight, just maintaining the water level, would be fooled into thinking the water was too low and would panic and keep injecting water into the boiler to make up for it. In the process they would overfill the boiler and in that state the water glass would be useless because they could not see a "level" separation in the glass and fear the glass was empty, doubling the panic! Upon opening the throttle to move the engine, liquid water would get to the cylinders and hydrolock them. If the engine actually started moving, the piston would soon be ramming into a slug of water and would blow the cylinder head off or bend the main rod.

I am not sure how well trycocks would work on a miniature boiler or if many people would be able to reliably "read" them, but it might be worth a try. Even in 1:1 practice they were an adjunct to the sight glass and were not the most reliable method to know the water level.


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## Nick Jr (Jan 2, 2008)

Cliff, you jogged my memory, thank you. My Mike Chaney Climax site glass is pretty accurate. Since it's been almost a shelf queen for the last couple of years I forgot. 
I also apologize for forgetting it was you what posted the proposed improvement.


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## Larry Green (Jan 2, 2008)

Hi Chester,

I solved this problem on my 4-4-0 (and another engine} by installing Bill Ford's electronic water level detection unit. It is reliable and easy to read, but unfortunately is no longer in production (Jason, are you reading this?).

As mentioned above, Roundhouse has a new design waterglass that does away with tube and small fittings--it has a bronze casting silversoldered to the boiler, containing both upper and lower ports connected to a large water chamber covered with a flat glass plate. The one on my RH Alco has proven to be bubble-free and relatively easy to read.

Larry


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## David Leech (Dec 9, 2008)

HampshireCountyNarrowGage said:


> I have not taken the sight glass assembly apart, yet. And before I do there are a couple of questions I'd like to ask. The first is to all 4-4-0 owners. Do you have this same problem and how are you handling it? Second. When the glass tube is inserted into the bottom elbow, how far into it is it placed? Meaning, does it get pushed all the way in until it touches bottom in the elbow or does it get placed in a measured amount so as not to block the water passage? I have read of placing a piece of wire inside the glass tubing to help break up the capillary action of the water. Does this help? Should the wire be lose so it vibrates? Should I replace the elbow fittings so that a larger glass tube can be used? Or should I just grit and bear it all?
> 
> It's been written that the locomotive is designed to run out of gas before the water, but with this sight glass problem I haven't been able to prove it one way or the other.
> 
> Thanks for taking the time to read this. Any help will be appreciated.


Chester,
1) I do not own this loco, so am unable to comment if other owners have the same problem, but ....
I have one Accucraft and some Aster locos, and none of them have ever given me false readings on the water gauge. From what I understand, it is very important that the lower gauge connection be far away from any heat source, as that is where the water is churning and bubbling which can cause bad readings.
2) I have heard of tubes being pressed down so far as to stop, or severely restrict the water flow.
I have also has a friend who went through two exchanges with Accucraft due to the lower gauge connection being blocked up with solder.
Maybe, IF you wanted to, take the glass out carefully, and just make sure that when water is put in the boiler, that it comes out as fast at the lower gauge connection. Likewise, with the bottom blocked, will water come out the top the same speed?
Also, BEFORE you replace the glass, make sure that the top and bottom fittings are indeed in alignment.
3) I have never used the wire, as have never had a problem.
Happy New Year,
David Leech, Delta, Canada


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## David Leech (Dec 9, 2008)

Larry Green said:


> Hi Chester,
> 
> I solved this problem on my 4-4-0 (and another engine} by installing Bill Ford's electronic water level detection unit. It is reliable and easy to read, but unfortunately is no longer in production.
> 
> Larry


There are three types available from Peter Spoerer Engineering in the UK:
http://www.peterspoerermodelengineers.com/
1) The regular Locosaver is a stand alone electronic water gauge. A red light shows on the LocoSaver box when no water is on the probe.
2) The LocoSaver Duo has two probes, and two lights on the box, one red one green. Can be used as a High-low indicator on the boiler, or one in the tender tank, and one in the boiler.
3) The R/C LocoSaver simply plugs into the receiver to get its power, and shows a red light on the very slim Locosaver unit when no water is on the probe. the probe plugs into the LS unit.
He also has bushes to fit into the boiler to go with them.
No page on the web site, but you can email him.
I have known Peter for many years, so just thought that I would pass on this information.
Happy New Years,
David Leech, Delta, Canada


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## HampshireCountyNarrowGage (Apr 4, 2012)

Hi guys,

Thanks for the replies, they are most helpful.

Nick, I have heard that about the wire and the effects on it from the temparture changes.

Larry, my freind Harvey has one of Bill's systems installed in one of his loco's that doesn't have a sight glass and he says the same thing as you concerning the temparture effects.

Peter, the boiler is too small to fit in try cocks and with them having to be so small, I agree with Semper about their effectiveness in showing water.

Cliff, from the photo, the larger passage fittings seem the way to go as well as a larger diameter tube. There isn't any room on the 4-4-0 for a blowdown valve so that won't work. I will keep an eye out for your results with your tests.

David, I believe you have solved the problem of the 4-4-0. The lower fitting of the sight glass is right next to the burner on the backhead. And without a whole new boiler to move it's location, there doesn't seem to be anything that can be done to keep bubblies out of the sight glass. 
I don't believe I have a blockage problem because of movement within the glass when adding water via the goodall valve.

I think the solution to my sight glass problem will be a larger diameter tube with larger passage way fittings. Now to gather up the needed parts and build up the courage to disassemble my locomotive.


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## Bob in Mich (Mar 8, 2008)

Here is My Site Glass.It is 9 mm and works great.This is a Larry Herget Desine.I have it on My Shay,K-27,Daylight


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## HampshireCountyNarrowGage (Apr 4, 2012)

Bob,

Is there a web site for this glass?


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## Bob in Mich (Mar 8, 2008)

Yes there is,Small Parts in Florida.But Now it is ran By Amazon.


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## GrizzlyFlatsFan (Jan 5, 2008)

Cliff, any updates on your design and testing? Does it work?


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## clifforddward (Jan 2, 2008)

Hi George....I'm deep into finishing up the steam regulator assembly for the Lawley at this time...have not worked on the water gauge for some time now...will get back to that once we have the soldered-on parts of the boiler completed.


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## HampshireCountyNarrowGage (Apr 4, 2012)

Hi Cliff,

I too am intertested in your water glass. Please keep us posted when you can. And I'm enjoying your Lawley build.


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