water glasses

[jscarmozza]

Does anyone know of a source for 1" scale sight glasses? Thanks.
John

[Builder01]

What diameter?

[jscarmozza]

There was a 3/16" diameter glass on the engine but the bleeder valued leaked so badly I couldn't get an accurate boiler water level. I wanted a larger diameter replacement but all I could find was a 5mm and I'm very dissatisfied with it, glass shears as soon as I go past light finger tight. Would like to get a 1/4" glass or larger.

[Builder01]

Your fittings are out of alignment, this is causing the glass to break. Use a round piece of metal first to get the top and bottom fitting in alignment, then try glass. If you want plain glass, McMaster Carr has 1/4". If you want blue line 1/4", here's a link that has it:http://www.livesteammodels.co.uk/shop/i ... ry&path=61

I use their 6.5mm blue line. It is slightly larger than 1/4". I opened up my fitting and it works, no problem.

David

[jscarmozza]

David,
Alignment is definitely a problem, the sight glass taps were both made on the back sheet instead of one being made on top the boiler, and they aren't parallel. Straight out, no good; 45 degree bends, worse; 90 degree bends, close; but now space and interference become an issue. The old sight glass body had a lot of wiggle room in the tube seat, the new body is very snug on the tube and there isn't much material in the body to over drill the seat, furthermore, the o-rings only fit in the nuts if you stuff them in prior to slipping them onto the glass tube, impossible to do when the body is mounted. Overall a poor product, hence, I'm looking for a replacement. Thanks.
John

[Builder01]

I would probably make new nuts that are larger across the flats. This would give you more room for O rings and a little more space to clear the glass. Then nut, and the fitting must not really touch the glass, it will break every time, otherwise. David

[jscarmozza]

I'll drill them out a little and see if that helps, thanks David.
John

[Bill Shields]

You might want to consider doing it with a glass like this on a 1" reconstruct I did a few years ago:

You can attach it anywhere via some copper tubing to the top and bottom

the glass sits on 2 o-rings, no nuts. The through bolt holds it all together.

Old Bill vanBrocklin design from 60 years back..works a charm

If you need drawings, I can come up with them for you (better than this working drawing)

This glass is 1/2" diameter OD

[Fender]

If the brass tubing is below the typical water level, wouldn't it be subject to "de-zincification", whereby the zinc is leached out of the brass, weakening it? Perhaps another reason to use copper in this location.

[Marty_Knox]

Dan, 'de-zincification' takes years, maybe decades. I have seen it, but after 20 years plus.
Many locomotives made in the 50's and 60's had brass fittings in the water glass that lasted a good long time.

[Builder01]

With the exception of the nuts that compress the O rings, I made my water gauge fittings and all other boiler fittings from bronze and phosphor bronze. Certainly no boiler bushing should ever made from brass.

[jscarmozza]

Bill, what seals the glass in the Van Brocklin design?
John