Alternative to the Vacuum Chamber?

Is it possible or practical to use a small gentle vibrator to vibrate the molding platform to get bubbles to rise to the surface and be less problematic? Even a small aquarium air pump (not attached to anything with the air hose) will cause gentle vibration. Placing it on the molding platform would trasmit the vibration to the mold easily. Just a thought.

Paige Russell8 months ago

Hi again John!

I haven't tried it myself, but I've talked to people who use a palm sander (without sand paper) to vibrate the mold board and help bring bubbles to the surface. I imagine the aquarium pump would work in a similar fashion.


At work we often tap the mould its self or rap the under side of the board/table with a mallet. It must be done gently. Another way we get rid of bubble (this only really works with lrg moulds, nothing sml-er then 20x30cm) is using an air gun to move the unset silicone around. Again be gentle and only focus on the top 5cm, trying to go lower would result in making more bubbles.

If your are talking about removing bubbles form the silicone, you should choose those that are with lowest viscosity possible. Fortunately, most of the silicone get gel after 2 hours allowing part of the bubbles to go to the surface but many mini bubbles remain in the mass which could affect those products that are pour with high temperatures (over room temperatures). Heat always make all products to get less viscous so it could help somewhat the rubber to be easier to allow bubbles to go to the surface but never go over 65ºF, specially if the silicone is tin base,because one of its component would evaporate creating a different problem.