Thursday, July 1, 2010
Gas Cylinder Belljar
This is going to be my vacuum chamber. I found it dumped in a ditch so I took it back to the workshop and took the brass valve out of the top. They are in there pretty tight! Before I cut into it I filled it with water to get any remaining gas out. This is a very important step. I then pored most of the water out and boiled the remaining water to get the steam to draw any that might remain out with it.
I cut the base off with my angle grinder. I did all this a couple of years ago in my initial efforts to get a vacuum system going. The base flange was a huge job. I think I cut it with a cutting tourch and spent the rest of the day grinding it into the right size.
The view port is a bit of 50 by100 mm box section and a face plate made of 3 by 25mm ribbon steel. All the steel is brazed together. I only have a stick welder so the brazing is a better option for gas tight seals.
I'm using JB Weld here to stick on the glass view port. I don't know if this is going to be a problem in vacuum but I've read some good reports about it. So what the hell! Its the slow kind by the way.I picked up a radiator bleed valve for €1.40 today. Its new and has a metal on metal seal. I hope it works. I threaded the steel washer which I brazed to the top of the cylinder. I will JB Weld the threads to get a good seal.
Today I have decided to do my electrical feed throughs in the cylinder instead of through the baseplate. I seems like a better option for practical reasons.