So, you want a vacuum chamber for your modeling projects and you just checked your sources on the Internet and the prices have just about scared you into a complete loss of bladder control. $200, $500, $800 or more? Are they out of their minds? But you need a vacuum sealer to make some quality tail fins for your scratch built 95 Impala. You know the wife is going to slowly skin you if you shell out those kinds of bucks. What to do?
I have the simple, easy, and—most importantly—the cheap answer for you. A vacuum food sealer. They come in different sizes, they have a nice variety of options, and you don’t have to spend an arm and a leg to get one. A basic model at your favorite “Big Box” store is about $50, or you can find them on E-Bay for even less money. I just ran a quick search on E-Bay and found over 1,300 listings ranging in price from $19.99 to $179.00. Lots of bags, bowls, and canisters were available also.
A vacuum food sealer will generally accept plastic bags and most of them also have a connection port to plug in a hose that connects to a bowl or canister to “pump it down”. For a small part such as a 1:25th scale valve cover, stick your filled mold into a vacuum sealer bag, insert it into the sealer and hit the start button. The vacuum sealer will evacuate all the air and when it reaches its preset vacuum reading, the built-in heating element seals the bag shut. Sit your mold, bag and all, somewhere safe and wait for it to cure.
For vacuum sealing larger parts, make your own vacuum chamber. Knock together a box using some 1/4" or 3/16” plywood and coat the insides of the plywood with silicone to create an airtight barrier. When assembling the box, seal all of the joints with caulking before screwing them together. Caulk the corners thoroughly and carefully and install a vacuum fitting in the top or side of the box. You can also install a vacuum gauge in the top of your home-made vacuum chamber to let you see how many inches of vacuum are in your vacuum chamber. Cut a large rectangular opening in one of the box sides and make an access plate out of clear Plexiglas. Use a cork gasket between the Plexiglas and the wood of your box and you’ll have an air-tight vacuum chamber without having to sell off the kids to pay for it.
Once your mold is inside your home-made vacuum chamber, and the access plate is screwed down, attach the accessory hose from your vacuum sealer and hit the button. Once you have as many inches of vacuum in the chamber as you want, hit the button again to stop the sealer’s vacuum pump.