1. Check the taps are both facing outward. Turn on plug switch at the wall.

Place your liquid to be de-gassed in the chamber. Replace the lid centrally, making sure the rubber seal is intact.

2. Turn right tap towards you to start the vacuum.
Note the needle on the dial begins to move.

3. Once de-gassing is complete, turn the LEFT tap away from you.

Now turn the RIGHT tap away from you SLOWLY.  It should look like this.

4. Before turning off at the wall turn taps back to the start position to relieve the pressure on the pump.

How to use the Vacuum Chamber

How does it work?

Vacuum chambers, or degassing chambers are an excellent way of removing trapped air pockets in problem moulds or for eliminating air bubbles in any liquid.

The basic function of a vacuum chamber is to remove all the air from within the chamber by way of an air pump, creating a vacuum or negative air pressure. This forces the air bubbles trapped in the liquid to increase is volume as they try to occupy the now vacant space created by the vacuum. As the bubbles increase in volume they are easily displaced and rise to the surface and pop.

The effect will cause the liquid to appear as though it is ‘boiling’ especially if there is a lot of trapped air present.

This stage is called ‘critical mass’ as the volume of liquid ceases to support the volume of air created, it collapses on itself, forcing even more air from the liquid. It is always advised to continue your degassing until critical mass takes place.

The bigger your air pump the quicker this process is.


Alternative methods for degassing liquids:

If you don’t have access to a vacuum chamber there are several ways we can achieve similar degassing effects.

1. One of the most popular ways is to use a vibrating table or platform to shake the air out. This can be as simple as a weighted motor fixed to a solid base capable of supporting the mixed liquid. Anything that vibrates against a fixed surface could be adapted as a degassing appliance, such as an old washing machine or compressor motor.

2. There is another commonly adopted method of mixing your liquid then pouring that into a second pot from a height, ensuring a thin stream is constant, the user can ‘tear’ air from the liquid. This works best with thicker liquids like silicones and some polyurethane rubber.

Where can I buy one from?

‘Island Scientific’ can supply vacuum chambers and evacuation pumps to order, catering for user requirements.

Prices are around £800.00+ for the chamber

£500.00+ for the pump.