05-21-2010, 11:11 AM
OK, I see. I thought you were trying to pressurise a large master in a mould box. Small parts shouldn't need to be degassed, or put into a pressure pot for that matter! Most people do this, as they're trying to make multiple parts for mass production to the public. Quality is a big issue, and since a lot of garage kitters are worried about parts having defects in them they use the pressure pot technique. These are actually intended for industrial paint use only! Modelers as well as garage kitters use them because of their design to pressurise resin for parts casting. Degassing is only neccessary if the parts are 3/8" of an inch, or more in thickness. This is because of warpage that can occour if the mould isn't thick enough to withstand handling, or if the parts have a lot of detail. This is why some use cornstarch to help break the surface tension of silicone across the parts until it sets.
~ Cobra Chris