Crystallization of Epoxy Resins

CRYSTALLIZATION OF EPOXY RESINS
Crystallization is defined as the formation of solid crystals from a uniform liquid solution. It occurs naturally with
foods such as honey, with snowflakes and with minerals. This is the same phenomenon that can occur with epoxy
resins and some curing agents.
Epoxy resin crystallization can be caused by high purity resins, moisture, temperature changes, low
viscosity resins or impure additives. In a clear resin, it could appear as tiny specks dispersed throughout, cloudiness
or a complete solid. Black or filled resins make it harder to detect.
As crystals form, they tend to settle to the bottom of the container since they are denser than the liquid. Eventually,
this can lead to the entire contents turning solid. Crystallization is not an indication of defective material. It can occur
in random containers from the same batch.
It is impossible to predict or eliminate. The Cure: There should not be any attempt to use crystallized resin until it has
been re-heated as it will likely lead to issues with curing or finished physical properties.
The following recommendations will resolve crystallization and apply to most manufactured Epoxies
* Place each container (Part A and Part B) in a plastic bag so that water cannot get to the epoxy product.
* Fill a sink or bowl with boiling water, and place jugs into the sink (not totally immersed, but enough to cover the majority of the jugs) and leave them sit for about 15 mins.
* Larger containers such as 20 Ltr (5 Gal) pails may require a lot longer.
* Rotate the contents occasionally and visually inspect to make sure there is no evidence of crystallization. Pay attention to the bottom of the container for any residue.

* Remove from boiling water and then remove the plastic bags.
* IMPORTANT: Leave contents cool to normal room temperature before using (may take a few hours).

A good practice that we recommend to professionals and crafters alike is to follow the steps above when making a purchase of any brand of epoxy and before using. Why? Well, following our suggestions, professional (and crafters) have been able to eliminate the possibility of crystallization, and additionally, bubbles and micro bubbles generated in the epoxy resin caused by transportation to the end user can be removed at the same time - a win win!