Greetings.
I came upon this wonderful forum quite by accident. I'm a sculptor who lives in Western Canada near the Rocky Mountains and I'm planning a project that requires me to make some silicone molds. Over the years, I've made many waste molds using a variety of materials such as plaster and wax, but I've never made reusable silicone molds, so there are a few unknown elements that I need to clarify.
I want to degass my silicone (slow, tin catalyst curing) before I pour it, but from the reading I've done it seems that living at a higher elevation, 3500 feet above sea level, means that I will only be able to achieve a maximum vacuum of 26 inHg, even with the very best of equipment (which I haven't bought yet). At least one of the experts I've watched on YouTube said that, "...you are wasting your money and your time if you cannot reach a vacuum of 29 inHg."
What I need to know is if I will be able to degass my silicone at 26 inHg (or quite possibly 25.5)? My thinking is that it should be easier to get the bubbles out of the mixture at higher elevation because there's not as much pressure pushing down on them, and so 26 inHg should be as effective at 3500 feet as 29.5 inHg is at sea level.
Any advice would be very much appreciated. Thank you.