Remove air bubbles from open casting mold

[granolite]

What can one do to eliminate air bubbles from forming over the top of resin mix such as polyester concrete.

 

[mohtogh]

I know some general solutions for this problem , but I am not familiar with your cast.
1. You can heat to the bowl of resin.
2. You should reduce surface tension of resin.By adding a solvent or by adding a defoamer such as silicone liquids.The best result achieved by adding the thinnest (and consequently the cheapeest)silicone liquid .
3. You should pour the resin in bowl, slowly and you can tilt the bowl during addition the resin.

 

[PrentP]

Use a vacuum. Place your container in a vacuum chamber (decicator) and evacuate it.
Regards,

Peter P

 

[Peka]

My best experians is to use a vibration system underneath the mold during the filling of the mold.

http://users.pandora.be/peka/

 

[Quad2T]

Spray a mist of rubbing alcohol over the rising air bubbles. This will causes them to burst, leaving the pour surface relatively smooth.