Every once in a while we get questions about Epoxy hardening, or getting chunky. Let’s see if we can answer that question, and address this concern —
What it looks like:
Crystallization shows up as cloudiness, free floating crystals, crystal masses, or as a completely solidified mass.
The hardened resin is due to the purity of our epoxy and most likely a result of temperature. Whether that is a temperature change, or from being stored in a cold place.
Why it happens:
The Crystallization that occurs is the same process that causes honey to crystallize in your home. The crystallization phenomenon is possible in all epoxy resin and hardeners that is very pure. Epoxy crystallization is very similar to other crystal growth. High purity, low viscosity, impurities, extreme cold, and temperature cycles all increase the probability of occurrence.
The fix is the same as it is for crystallized honey — heat it up. You can heat the resin in hot water, or microwave it for a few seconds (duration depends on the power of your microwave — GO SLOW and BE CAREFUL!). This will dissolve the crystals and restore the epoxy to a useful state.
For those of you suffering from insomnia, here’s a technical brief on this phenomena —