Q. We are using epoxy adhesive and have a few questions. How can we speed up curing? The instructions are clear that we cannot add more catalyst or hardener. Also, we tested one joint the next day and noted it failed rather easily and we saw that the failed joint where the adhesive was appeared grainy and not smooth. What is this? Finally, how can we clean up cured epoxy?
 A. You can speed up curing by heating the wood and surrounding air. Roughly 17 degrees F hotter will cure twice as fast. By the same token, 17 degrees cooler will cure half as fast.
 The grainy appearance of a broken joint is typical of using too much pressure with epoxy. When there is too much pressure the epoxy is squeezed out of the joint and the chemical activity cannot occur. (I believe that most bad experiences with epoxy result from using too much pressure.)


Find more Wood Doctor at FDMCdigital.com

Gene Wengert, aka The Wood Doctor, troubleshoots wood related problems, and explores lumber and veneer qualities and performance, species by species, in Wood Explorer, inside FDMC's Knowledge Center.

 Also, you should be aware that although the epoxy cures in a few minutes, total cure and maximum strength will not occur for 24 hours. You must wait for full strength to develop before testing.
 As far as clean up, I contact West Systems and asked them, as I did not know the answer. They stated that due to the high chemical resistance of cured epoxy, removal must be done with an epoxy-type paint stripper containing methylene chloride. Uncured epoxy resins and hardeners can be cleaned up with ketones, alcohols, or lacquer thinner. White vinegar will clean up unmixed resin components.


Have something to say? Share your thoughts with us in the comments below.