The Steamboating Forum

On sight level gauges. It looks as though the spacing between threadolets is 13.5" as standard. Although that seems a bit far for a small boiler. Is there a standard spacing on small power boilers?

-Ron

As long as the bottom of the glass is a minimum of 2" above the firebox crown, no there isn't. It is good practice to make sure the top of the glass is around 2-3" below the steam outlet so that at max water level the engine isn't priming, but that is engine practice, not a boiler management issue.

Greg

Greg,

Sounds good. We are within those parameters.

Thanks, Ron

This must be a reflex gauge you are talking about. One of the small advantages of a tubular gauge (other than price!) is that you can cut the glass to any length.

Mike

Re: Cutting the glass, yep that's true. Just trying to make it easier for an end user. I have one of those tubing cutters around here somewhere - works pretty good.

My brother is starting to build small power (our size) boilers. He has one almost finished. 16" diameter X 18" tall 48 1-1/4 tubes. Built to code or close to it. ASTM A106 shell, A178 flues rolled and seal DC inverter welded with 7018 stick. Should be a good boiler. He's going to ask about 2500 for it.









-Ron

I've never owned a cutter. Would a cutter for copper pipe work? Hmm.

I take a triangular file and score the tube all the way around. One spot would probably be enough. If I'm alone in the shop I set it up on a board where I can tap it with a plastic hammer opposite the score mark.

If I'm showing off for a customer I tie a string around it at the file mark. A drop or two of kero or such on the string and then light it. As soon as the flame dies down some I put it under the tap. Tink. Been cutting jars off this way for years with no score mark.

Then take my orbital sander to the end to square it up and bevel it. Voila!

In the case of the jars I use a torch to flame polish the cut edge. Glass is amazingly forgiving except for mechanical shock or sudden cooling. Doesn't conduct heat well either. I can hold one end of a tube while the other end is glowing.

Mike

Here is the tubing cutter I use:



It scores inside, works really good. I had to replace the short glass tubes in my drip oiler, this cut them no problem.

-Ron

That is the coolest thing. I would have walked right by it on a table of tools.

I've never heard of scoring on the inside of a tube. I like that there is some give in it so scoring it wouldn't break it at the same time. Now I'm going to look at an extra pipe cutter I have and see if I can make the plunger that holds the cutting wheel be spring loaded.

Mike

Just looking at the various tools Ron has shown I think he subscribes to the saying "I'd rather have a tool I didn't need than need a tool I didn't have!!" I just got to get one of those tubing cutters! I've always used Mike's method but really here's a tool I should have -just because! Oh yea don't forget to have a spare tube or two [and gaskets] on board-just in case!! Den

I got lucky and picked one up at a flea market for $1USD. I am told that the cut gauge glass ends should be heated with a propane torch until the sharp edges just start to melt. Keep the tube turning while doing this to evenly heat the cut ends.