Buying a decent size vacuum chamber costs upwards of £1000 but all we really need is some plastic tubing, thick plastic sheet to cap the ends, pvc hose and silicone.

I bought a thick walled aluminium cooking pot from Ikea ages back and I modified that.

It had two handles on the side with holes drilled through and pop rivetted. I just ground the rivets off, filled the holes and around the outside of the holes with epoxy and put some rectangles of thin metal over to cover.

To make the top I just bought some thick (2 inch or so) perspex, fitted a nipple for the vac pump and fitted a small gauge. I sealed the perspex against the pan using some gum tape.

You can pull pretty much as much vacuum as you like, never had any issues. Plenty of space inside and total cost was less than a tenner! (Mind you, I already had the pan )

I did look at getting bell jars but they cost a fortune!