are you using poly or vinly ester resins? or epoxy. how are you mixing it and at what temp. poly and vinly esters will gas off and you need to let them gas off befor pully it in if your pushing it in the at the other end to much pressue can cause that to. the warmer the batch the better especially if your using epoxy. hope that helps

You can put the epoxy in a chamber or a bell jar and pull a vacuum on it to remove the gas bubbles. The manufacturer should be able to give you info on how much for how long or just experiment. As an alternative you could put the assemblies in a chamber after you pour the epoxy but it is usually easier to outgas the epoxy first.

Slow down the process. Experiment. Just waste some of the stuff. Record humidity and temperature. Give more information. Hope you have read the instructions. It has happened! Ah, and have fun doing it. Ky.

to help we need more info. What resin, what temperature is the mold when injected? Is the mold heated further after injection? What kind of release system are you using?

Some potential fixes with the info we have:

1) de-gas the resin before injection.

2) once the resin is injected you want pressure in the mold or at least no vacuum.

3) slow down the cure speed by reducing the temperature.

4) silicone releases can cause problems with injection molding.

Also watch how the raw material is stored. Open boxes / bags of material can collect humidity. We keep or resins in a warm 85F oven for a minimum 1 hour before molding and only in daily quantities.