Articles
The Usage Of High Temperature Epoxy
High temperature epoxy is a small niche of epoxies in general. In chemistry, epoxies are thermosetting epoxide polymers that polymerizes and crosslinks when they are mixed with a catalyzing agent, also called "hardener".
The most common use of high temperature epoxy is as an adhesive. Its high performance makes it appropriate for the construction of aircraft, automobiles, boats, bicycles, snow boards and for other different applications where high strength bonds are required. A high temperature epoxy can be used in almost any application. It is a perfect adhesive for wood, metal, stone, glass and some plastics and it can be made in many ways: rigid or flexible, colored or transparent, with a fast setting or extremely slow.
Epoxy adhesives cured with heat have more heat and chemical resistance then those cured at room temperature, and that makes them almost unmatched among other adhesives.
It is known that regular epoxies (Bis A epoxies) can handle temperatures (constant or repeated) around 160 to 170 degrees F, in dry conditions. In wet conditions these temperatures drop until 140 to 160 degrees F. On a non regular basis, they can handle a so called service temperature of 300 degrees F. On the other hand, high temperature epoxy may handle in dry conditions constant or repeated temperatures of about 300 - 350 degrees F. in order to obtain this feature the epoxy need a few hours of additional curing at temperatures of about 130 - 150 degrees F.
Making a high temperature epoxy involves a complex process and requires different chemical products. Novalac or regular Bis A epoxy resin can be used in the first part of the making process and hazmat as high temperature curing agents for the second part.
One important thing is that is impossible to obtain both high temperature resistance and chemical resistance. It must be one or the other, depending on what is needed most.