Silicone Mold Tutorial: Vacuum Degassing Silicone

Here are some of the basic tips for vacuum degassing silicone. In this tutorial we make a very basic silicone block mold with TinSil 80-15 tin cure silicone. TinSil is a relatively thick silicone (12,000 cP) so it warrants vacuum degassing. Vacuum degassing at 29 inches of Mercury ensures a complete vacuum wherein bubbles cannot exist.
The vacuum setup used in this video was ~2.5 gallon pot with a 6 CFM vacuum pump.
As mentioned in the video, here is a link to our video library: www.brickintheyard.com/pages/...
TinSil 80-15 can be found here: www.brickintheyard.com/collec...

[@theadventuresofjavier8698]

Thank you for the videos you post. I have made several molds for missing model airplane parts for many model planes i made in my youth. The resin parts look great.these vids gave me the conference to start casting my own parts. Happy New year.

[@bitymoldsupply]

Thanks! Happy new year to you too!

[@HenkJanBakker]

Question:
Degassing *after* you poured the mold. Is that a (good?) option? Provided you vacuum chamber is big enough / pattern small enough of course.

[@bitymoldsupply]

I have not tried that so I don't know what would happen. That said, you would have to be sure that the vacuum condition would not collapse or damage your pattern. Your mold would also be limited to what you could fit into your vacuum chamber.

[@HenkJanBakker]

@@bitymoldsupply So basically a lot of risk and no real upside. Makes sense. Thanks.

[@andyfilms]

You'll problably wind up with more bubbles on the surface of your part as they get pulled out.

[@bitymoldsupply]

Indeed. That is my thought. Sometime I'll try a test mold like that and see what happens.