Has anyone ever made their own vacuum chamber using a pressure cooker?

Question

HOw well does this work?

I need to find a better solution for moldmaking and casting.

The way I do it is too time consuming and I'm not going to spend a few thousand on a vacuum chamber for the amount of casting I currently do.
Thanks!

thanks ... that sounds interesting! I use silicon rtv for molds and eco-resin for castings


if i try this, 'll let you know!

Answer 1

The problem I see is that the gasket is placed and surrounded by metal to keep it from blowing out under pressure. Having handled and washed one a number of times, I have to wonder if the gasket would be sucked right in, breaking the vacuum.
On the other hand, it would be easy to test since you could put a hose on the weight nipple and see what you can pull without, probably, collapsing the heavy metal.
How much of a vacuum do you need? The vacuums for investing castings for metal are only several hundred, which is too much for me.

Answer 2

Haven't tried that but had some success with a simple vacuum pump and a homemade chamber made from a section of 24" pipe fitted with a gasket and a heavy duty plexiglass lid. Had to tap a fitting into the base of the pipe. Not sure exactly what materials you're working with but we used it to remove air from silicone in the process of making skins for animatronic characters. Also might want to try a household vacuum cleaner motor if you don't need as much power. We used that, some perforated sheet metal and a heating element from an old stove to make our own vacu-form machine for shaping sheets of acrylic . Come to think though the pressure cooker seems ready made and I'd be curious to know if you try it and have success.