I was corresponding with a person about building a wood/plywood plane. At one point, I realized that he had been reading about polymerization and believed that cured epoxy will turn to something like rubber if exposed to about 45-55°C (113-133°F), a temperature that might well be encountered in many parts of the world. This has something to do with epoxy's glass transition. This person's solution was to heat-treat the aeroplane, or at least the epoxy-containing parts of it, that is, bake them at 70°C (158°F) for 12-16 hours. I must say I was surprised. I had never heard about this need for heat treatment. Of course, I am just starting to learn about building aeroplanes. Is it really necessary?