Professionals and Amateurs Together

Eliminating Bubbles in Epoxy


To eliminate bubbles in epoxy, do you cure the epoxy in a vacuum or a pressure pot.—Dale Corliss


Richard Oedel replies: Some epoxies are formulated to pour without bubbles, but almost all have some. Here are several solutions, all of which will help.

Stir slowly. You introduce bubbles with fast stirring. Patience is required. Stir slowly.
Pour in a thin strand such as when pouring into molds. If you are pouring from a cup, pour from very high up in a very thin strand—bubbles form less easily. Do not let the strand of epoxy from the cup break up before it enters the pool of epoxy below.

Flame treat the surface but beware that epoxy can burn. Using a propane torch moved quickly over the surface immediately after pouring brings bubbles to the surface and they pop. Move quickly and uniformly. Don’t try to heat up the epoxy. If you can get a fan-shaped flame nozzle, all the better. Experiment first, with a fire extinguisher by your side!

Bruce Wedlock replies: Bubbles can be eliminated by lightly tipping off with a disposable natural bristle brush.

Tags: Epoxy