I'm building a vacuum oven since I found an industrial highly corrosive resistant vacuum pump and a few boxes of the oil it needs all for about $50. I have the general outline of what I want to do, but I have a couple questions. 1. I plan on this oven reaching about 750-800 °F max on a central platform in the center. My thought is the vacuum shouldn't conduct much so I just have to worry about heat flow from the platform to the bottom of the oven. So that should keep the sides a bit cooler but I'm not 100% sure that's correct thinking and would like to calculate the max temperature the side of the oven and top of the oven would reach. Main reason for this is so I can determine if high-temp polymer o-rings can be used on certain sections. Don't have much of an idea of how to calculate that odd geometrical path of heat flow. 2. If polymer o-rings are out of the question I need an air tight seal on the door and quartz window. Any ideas? The pressure difference when opperating is only going to be about 14psi but I'm out of my expertise when dealing with high temp applications.