I used a paint pot for pressure casting and molding successfully for about 10 years. I then converted a small paint pot I was using for resin casting as a vacuum pot as well. It can be used for both as its just a matter of changing the lid and set up.
Here is my converted paintpot I use for my vacuum pot. I started vacuuming my rubber as it made more sense as some of my molds were too large to place in my paintpot while curing. When you vacuum your silicone you can pour you molds outside pressure pot. However you will be able to pressure cast them once they cure due to removal of majority of air before curing. So if you want to pressure cast your molds you have to do one of 2 things. vacuum the rubber and then let dry outside the tank on a flat surface. You can also create your molds in the pressure pot meaning the silicone will cure in the pot under pressure.
I have taken a few pics of my vacuum pot set up. The paint tank used was obtained from harbor freight the 2 1/2 gallon size. I put a plastic bag inside as a lining and add a 1gal. bucket with mixed silicone in it for run. Do about 1/2 gallon of silicone at a time. should you want to do more. you can spray mold release or matte finish in the tank itself and pour in there. you will get about 1 1/2 gallons done but you will have to clean the pot of dried silicone later on.
The lid can be made from an acrylic provider they will need the dimensions of the lip of tank or pot to make the correct lid. I was lucky as fritz( headlesshearseman) new some people who do this by him so I paid to have it done by them. The lid is expensive but necessary as you need it to be strong to hold the suction and be able to view the silicone rising and settling. A gage that measures vacuum pull up to 30 will suffice.
The last of main components is the vacuum pump. This hooks up with an air hose which you cab get with some hose clamps from hardware store. I purchased this new on eBay. there are several brands to get . I can only show what I use Robinair 5500 . You will need some compressor oil as well to operate. The new in box ones come usually with a starter bottle.
once you mix your silicone you will need to put the lid one start up the pump. Press down on the lid to get the vacuum started. you will see the Gage arm move when its working. keep an eye on the rising silicone. Turn off switch if if is going to hit the lid. You don't want silicone getting into the tube and ruining the pump. You can tun it on and off until it rises and settles down and you see tons of bubbles breaking on surface. I usually leave mine on 10 minutes is plenty. You can see my equipment is used and not the newest but you get the idea.
