Can I make a vacuum chamber with an air compressor?

August 15, 2018 9:53 AM

I've been getting into resin casting and it's a blast but eliminating bubbles is a lot harder than it seems. Vacuum casting is the go-to for a lot of people but dedicated vacuum chambers cost quite a bit of money. I already have a small air compressor. Are there any attachments I can get that would allow me to use that to create a vacuum in a sealed chamber?
posted by Socinus to Technology (5 answers total)

Yes. A venturi vacuum. They use a lot of air to get any sort of reasonable vacuum so unless you have a fairly large compressor your results might be disappointing.
posted by Mitheral at 10:10 AM on August 15, 2018 [1 favorite]

For $50 you can get a pump in the 'good enough' category. Search for "rotary vacuum pump" on ebay
posted by Dmenet at 10:25 AM on August 15, 2018

How much hacking about are you willing to do? There are ways to make vacuum chambers out of old parts, but that assumes that you have or can scrounge those parts and then are handy enough to put them together.

Here's a sort of typical example. Youtube has a bunch of others.

However, as Dmenet points out, old vacuum pumps are pretty cheap, then all you need is a pressure vessel. For a 1 atm vacuum, that doesn't even need to be super strong. A pressure cooker from a flea sale table is generally way more than enough.
posted by bonehead at 10:28 AM on August 15, 2018 [1 favorite]

Sorry: wrong link. This is the one I meant to include.
posted by bonehead at 10:47 AM on August 15, 2018

If you’re just trying to pull bubbles off of a mold you can run your compressor as a makeshift vacuum pump by figuring out the right “plumbing” to connect your chamber to the compressor inlet. An inverted Pyrex bowl on a sheet of plastic makes a decent chamber.
posted by doctord at 12:07 PM on August 15, 2018