Anyone know where I can find more technical tips on cutting tubed sight glass?
I need to cut one to a specific length and I don’t want to damage or crack it doing it wrong. Tried to see if Keith Appleton had videos but I don’t see specific ones.
Standard lab technique is to simply score the tube on one side with a fine triangular file, then placing thumbs together on the opposite side from the score, do a quick snap to break the tube. If you wish to "seal" the break, use a blow pipe in an alcohol flame (a propane or butane torch will work as well) to bring the edges of the break to a bright orange and observe the sharp corners rounding off. Don't go too far with this "healing" of the break or you will likely bulge the tube O.D. by rounding the end excessively and make a final fit in your compression nuts more difficult.
Hope that helps.
Good luck.
As for me, I use a small fine file (the sharp edge) to score the tube, all around, where you
want the break. I put my thumbs closely to the left and right of the score line and the rest
of my fingers to the other sides. A deep breath and a quick snap movement and you are done.
I always clean up the ends with silicon carbide paper - 320 works pretty well and allows you
to get the exact size needed. Sand a bit, test the fit, sand a bit, test the fit is the idea.
In fact, I just used this technique for an Empire 30 sight glass. I use doubled over and twisted
teflon tape as a sealer. Other steamers use different methods with success. Hopefully, you have
enough glass tubing to try again if it doesn't work well the first attempt. Keep in mind that some
tubes sit exactly between the fittings and some are meant to go in a bit on both the lower and upper
fittings. My Empire 30 was like that whereas a later version 43 has a sightglass that fits exactly
between the fittings. Go figure.
The file will dull a bit, but is worth it. I've used the same 'marking' method many times
with the same file and I still find spots on the file that work.
Good Luck,
Wayne
I mark the tube with a fine tipped Sharpie and use the same tool as Richard.
I mark the tube with a fine tipped Sharpie and use the same tool as Richard.
Well, that there is fine praise coming from you Frank - which for the record, I also use a fine tipped Sharpie to mark the glass for cutting!
I have done it many ways, the simplest way I do it now is to chuck it up in the lathe (with thick paper cushioning it) mark it where I want to cut & use my dremel cut off wheel to score it & cut it off, been doing it that way for years now.takes less than a minute.
Thanks for the feedback yall. I have many different methods to try.
Like Bruce I also use a Dremel, its very hard to snap off a very short sections of glass tube.....Dremel makes light (and very accurate) work of it.
(Take simple precautions when cutting glass with a machine)
I mark the tube with a fine tipped Sharpie and use the same tool as Richard.
And I "third" the motion.
