Pour and pop bubbles

Pour slowly, in a thin stream, into the lowest point of the mold and let the resin find its own level. Stay inside the depth per layer on the label: about 1/8 inch for coating resin, 3/8 inch for casting resin, 1 to 2 inches for deep pour. Deeper molds are filled in layers, each poured once the one below has set but is still slightly tacky.

Bubbles rise for the first minutes. Warm resin lets them go more easily, which is why cold bottles are warmed in a water bath before mixing. On epoxy, a quick pass of a heat gun or torch clears the surface, and a toothpick frees bubbles caught in corners. Keep any heat moving and brief. How to get bubbles out of resin lists the methods in order.

For dice, miniatures and other clear castings with sharp corners, casters use a pressure pot: 40 to 60 psi shrinks the bubbles until they cannot be seen. Use only a pot rated for the pressure and never exceed its rating. A vacuum chamber does a different job: it pulls air out of mixed resin or silicone before the pour. Casting without a pressure pot shows how far you can get without either.

Ready to move on when: The mold is filled to the line, the surface is free of bubbles and the piece is covered against dust.