|Home » Forums » Adhesives » Message||Login|
You are not logged in. Consider these WOODWEB Member advantages:
The key to using epoxy adhesive11/30
Certainly, epoxy adhesives are excellent adhesives, but it seems that many users forget one basic requirement for epoxy:
Epoxy adhesives cure to a strong adhesive with heat. The heat is generated within the adhesive. If the adhesive is
A second critical aspect of epoxy adhesives is that they (the resin and the catalyst) must be mixed in the precise ratio specified. This ratio is determined by the manufacturer so that the heating is correct...not too hot or not too cold....among other aspects of the chemistry.
Hmmmmmmmm....A lesson learned lately Dr?
Same song I've been singing for years but new wording. It is prompted by two new users of epoxy that had excessive pressure on the joint while curing and didn't know that it was wrong and causing problems. Obviously, I am called in as a consultant when folks are having problems--it was true in these two cases.
It just occurred to me that when I wrote "too thin" that it might not be clear that I was talking about the amount of adhesive in the glue line (the glue line is actually too thin). This thinness could be because there is not enough adhesive applied or because there was too much pressure and that squeezed out too much adhesive. I was not referring to the viscosity of the adhesive.
I don't see what the big deal is. These problems could be avoided by simply reading, understanding, and following the instructions.
Somehow most people skip this step, but I don't know why.
Epoxy is not hard to work with.
Most people can mix the parts together within the 10% accuracy required.
The most common failures occur when people do not abrade the surfaces(80 grit for any material) and/or squeeze all of the epoxy out of the glue joint.
The temperature aspects of epoxies are well known and there are many techniques used to manipulate them.
Common wood glues like smooth surfaces and thin glue lines. Exactly the opposite of epoxy.
I encourage people to read the How to guides that are on the System3, MAS Epoxies, and of course West System Epoxy website.
The Gougeon Brothers(West System) are kind enough to provide a free PDF version of their classic 300 page book on Boat Construction. Well worth a read for any woodworker.