I've been using this to degas silicone and it gets the job done, but it's a little slow and could benefit from a stronger vacuum pump.
Some tips -
- Use a silicone with a pot life of 15 minutes (cure time 45 minutes) or more, otherwise your silicone may gel while pouring after waiting for it to fully degas.
- Mix your silicone components in a jug (with a spout) that is at least 8x the height of the mixture in the same jug, or your mixture will rise so high while degassing that it will spill over the edge.
- Don't put the jug of liquid silicone directly under the opening in the pot lid. If the mixture is under the opening, air will re-enter the chamber when you open the inlet valve and cause a jet of gas to push itself into the mixture, creating more bubbles. If the container you're using is too big to achieve this, don't open the inlet valve all the way - just let air in slowly so it doesn't smash into the mixture.
- after degassing, pour the silicone from 20-30cm above the mould box or positive so that it pours in a thin stream, and any remaining bubbles will pop.