Quote Originally Posted by bridger View Post
it's an older one, from a thrift store. it has a rubber seal, though, and I see what you mean- there's nothing to keep the gasket from being sucked in. drat.

last night I spent a couple of hours making a retainer ring for the gasket that would spread the gasket tighter the harder the vacuum. made it from mdf. came out this am. and gave it a quick coat of shellac. while it was drying, I thought... am I overthinking this? grabbed the pressure cooker, hooked it up to the vacuum pump and plugged it in. after it pulled down for 30 seconds or so, I could no longer budge the handle. pulled the plug and after 5 minutes or so I could start to move it. I think I don't need the retainer.....

my vac pump is a compressor pump from some old heavy duty fridge or freezer. one advantage of using these is that you can hook it up and just leave it running all night if necessary. it maxes out around 25-30 inches of mercury (12-15 psi) plenty for this process and safe for the chamber. the pump will hold vacuum for a couple of hours, so the leakage is mostly from the pressure cooker. no matter, I'll just leave it running for the time I expect the resin takes to gel.

now to test if the japan drier will kick off a good short oil varnish sans oxygen.