Office of Steam Forum for Model & Toy Steam Gas & Hot Air Engines

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.   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.