My man, the insane bubbles you got was from water moisture sucked into the foam. All resins foam up from water contamination. I have been in the special fx /toy industry for near 30 years. Trust me on this. If you need to measure how much resin you will need, use dry white rice to fill the area then measure that in a measuring cup. It will give you the same volume and keep the area dry. Keep all moisture away from resin.