I never heated it. It's viscosity is low enough that it spreads like spar varnish. We never heated it when using it as a sealer coat on boat brightwork, and never had a finish lift as a result. We had company reps advise us to never thin epoxy with solvents and that heating the surface whether to promote absorption or to speed curing was a surefire way to lessen the integrity of the epoxy- to one degree or another. The only joints I ever had fail that were done with epoxy were a couple of times I was in a blazing hurry and used heat lamps to speed the process. Lesson learned- think ahead.
205 and 206 were used for many exterior joinery/lamination applications too, to the tune of a couple 50 gallon drums a year. The key was good UV protection afterward via quality varnish or paint. UV light will degrade epoxy quicker than anything, short of heat and solvents. This from a lot of years in the wooden boat building game.
