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#Post#: 43880--------------------------------------------------
Sight Glass Bending
By: PO9R4S4CHE Date: July 10, 2021, 8:12 pm
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Had a sight glass for my Bing 1637 [130/112?vulcan?] and didnt
want to use or break the original. I had 3.5mm od and 2.5mm id
sight tube left from a weeden repair.
I decided I wanted to keep the original and run with a
replacement.
Its very tricky to bend glass. it is not mechanical in the least
or engineer based. it seems more artistic and casual for sure.
I tried making a jig the first round but thats too structured
and serious for glass. Instead I found it was easier to heat
the measured bend spots and let gravity and coaxing with a metal
tool worked best. Then a full cool down.
This was either pyrex or borsilicate tubing. You need to slowly
casually heat it.
it stays pliable for quite a while. It doesnt spread heat as
far as I thought. I didnt use gloves but then again I do not
feel pain [only emotion]. I think it turned out well.
As for the Bing engine I used wilesco rubber gaskets that fit
around the glass and some wilesco washers and its the most water
tight sight glass I have.
any questions ask. any advice appreciated. let me know if u
want to see a bigger image.
sorry for spellings and punctuation im on my phone.
[attachimg=1]
#Post#: 43888--------------------------------------------------
Re: Sight Glass Bending
By: Dampfopa Date: July 11, 2021, 5:23 am
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Jason, I take a similar approach to making water level
tubes/viewing glasses as you do. However, I take conventional
glass tubes with the diameter and thickness required in each
case. I cut the tube to the required length with my Dremel and a
thin cut-off wheel. It is also possible to run a simple glass
cutter around the tube once under light pressure and then break
it off.
I have built myself a simple tool from dry beech wood, similar
to yours. I drilled a hole in the diameter of the tube 2 cm from
one end of the beech wood. This hole is flattened by me towards
the bending side (the end of the wood 2 cm away) at the top of
the edge. The required dimensions of the tube, where the bend is
to be made, I mark with a black pen. I put the tube into the
hole up to the first mark and lightly glow the glass at the
marked spot with my small gas burner. Then the glass tube is
simply bent at right angles by hand. I repeat the process for
the second bend.
Please do not think that I have fireproof hands and fingers. :D
I always use very thick leather work gloves when bending the
tube.
By the way, you can deburr the sharp ends of the tubes by
annealing them briefly with a gas burner. I make the seals of
the tubes from matching silicone tubing. It is cheaper than the
Wilesco seals and can be cut to the required thickness with a
very sharp knife or a scalpel.
#Post#: 43940--------------------------------------------------
Re: Sight Glass Bending
By: Earlytimes Date: July 13, 2021, 11:16 pm
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Good description both. Using Wilesco gaskets is good to know.
#Post#: 43996--------------------------------------------------
Re: Sight Glass Bending
By: PO9R4S4CHE Date: July 17, 2021, 5:44 am
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Update. After second run we are leaking again I think im going
to use a little silicone gasket seal. In the meantime since
there was the leak I took the time to paint the glass in what i
think and believe they were painted. looking at metal hardware
i can see paint remanants (and gasket) anyone aware? seemed my
"original" sight glass had similar paint. I love how much more
visable it shows. I tried to match the flywheel with the color
visable thru the water. [attachimg=1]
#Post#: 43997--------------------------------------------------
Re: Sight Glass Bending
By: PO9R4S4CHE Date: July 17, 2021, 5:46 am
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Pretty Sharp looking if ya ask me![attachimg=1]
#Post#: 44012--------------------------------------------------
Re: Sight Glass Bending
By: Dampfopa Date: July 18, 2021, 5:47 am
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When I get one of these old machines, one of the first tasks I
do is I take down the water level and see what the condition is.
Usually the pressure plate for the seals is affected by rust.
The plate is then meticulously cleaned of dirt, paint residue
and rust. Then I paint it 2 - 3 times with rust converter. Works
great as a primer and prevents rust from forming again. Then I
paint the plate with a commercially available enamel paint from
the model building sector. I have not yet tried the Wilesco
cardboard seals. These gaskets are very good for sealing
connections from steam whistles, filler plugs and safety valves
to the boiler. However, they must be replaced depending on the
frequency of operation. I therefore prefer the homemade silicone
gaskets, which are much more flexible. Important when installing
the water level tube and the pressure plate is the absolute
cleanliness of the parts. Also the holes in the boiler for
holding the tube, and their surroundings must be metallically
bright, so that the seals in the surface can lie cleanly.
On a machine that was visually in good condition, I have
experienced a nasty surprise. I have not paid the necessary
attention to the water level and heated the boiler. The machine
started very well. After about 1 minute steam came out at the
seals of the tube. The discharge was then explosive and caused a
huge mess. One of the previous owners had sealed the water level
with window putty. Water, heat, window putty and pressure, not a
good clash.
Fortunately, no one was hurt. That was a lesson to me though.
You can see why I'm a little picky about this now.
#Post#: 45175--------------------------------------------------
Re: Sight Glass Bending
By: Earlytimes Date: September 13, 2021, 3:48 pm
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I'm in the process of making a U bent glass now. The first
bend is easy.... then I came to this thread to see how to make
the second. I need to make a jig I guess. Getting both bends at
the same angle and the correct distance apart is a little
challenge ;D
#Post#: 45177--------------------------------------------------
Re: Sight Glass Bending
By: Dampfopa Date: September 13, 2021, 4:38 pm
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It's a little late and time to go to bed. If you have time until
tomorrow, I'll post a sketch.
#Post#: 45178--------------------------------------------------
Re: Sight Glass Bending
By: Earlytimes Date: September 13, 2021, 4:46 pm
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I just cleaned up the old fittings and it looked like window
putty was used to seal the glass. The sight glass got broken in
shipment so I never tried to run the engine. I have had one blow
on me and it was kinda scary to say the least.
I broke the first glass 1/2 way through the second bend. I'm
leaving the glass long but may try Jurgen's approach of cutting
to length first, if I can't get a clean cut after bending. I'm
glad I have a lot of glass ::)
#Post#: 45179--------------------------------------------------
Re: Sight Glass Bending
By: Earlytimes Date: September 13, 2021, 4:47 pm
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Talk to you tomorrow Jurgen... :)
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