Hi all:
Out of curiosity, is it possible to buy affordadable vaccum chambers for modelers? If so who sells them?
Thanks!
Xavier
Mate,
That’s a hard one - but I’ve been looking around - and I’ve decided that I’m going to use a pressure cooker (like you use on top of the stove to cook stews) for the pressure vessel. They’re tough, and can hold a great deal of pressure, therefore can also take a great deal of negative pressure. You can drill a hole in the vessel for the fittings for the lines to the pump.
The vacuum pump is another matter - I’ve found a likely candidate at a local jewllery manufacturing supply store. They’re not cheap - but it pays to spend a little more than you think you can afford - you’ll only kick yerself later if you find that you should have bought the more expensive one…
These chambers are used a lot for plaster - when someone is making a “lost wax” type of casting (done a lot with rings, brooches and bracelets), so you might try to check with these types of stores. They should have a fair number of different sizes to pick from.
Alternatively, check the yellow pages for “vacuum pumps” - and make sure that the pump is large enough to adequately evacuate the cubic capacity of the pressure vessel quickly enough - and make sure it can create vacuum to minus 0.9 bar (1 bar is about normal air pressure at sea level, or 101.3 kilopascals).
If you’re evacuating air from RTV rubber molds, the time frame isn’t really that important, but remember, if you’re evacuating the air from polyurethane resin, you have to take into account the pot life of the resin - if it “goes off” (or hardens) before it can be fully evacuated, you’ll just end up with a bubbly, foamy hardened mass. If you can evacuate it quickly enough, the resin will lose all air bubbles, and will fill all voids in the mold.
Good luck, mate.
Lee tree:
Thanks very much for the tips and links [:D] I’ll take a closer look at the jewlery manufacturing supply stores. I sure hope that someone can sell us an inexpensive vaccum chamber.
Thanks again!
xavier
Xavier,
No problems, mate! If you get one, let me know how you get along with it.
I picked up a small vacuum chamber from a company called Alumilite. They make casting resin and distribute Dow corning silicone rubber. They recommended http://www.bestechind.com for a vacuum pump. I’ve been very satisfied with it for degassing rubber.
Hey jack21771, I have been thinking about getting a qoute for one from Alumilite. Do you have the one made from a PVC tube? How much do they cost?
Thanks
I have been using a Foodsaver, mine has a vacuum lid that fits a Ball jar. I drop the mixing container in the jar, stick the lid on and hit the button, it de gasses in a matter of seconds and is under $100.00
I use a Pressure Chamber… Works well enough for me!!
Balta,
The chamber itself was about $125.00. The part that is kind of costly is the vacuum pump. A new pump runs from $200.00 to $250.00. I found one in good shape at a used tool store for about $75.00.