I built a set of cowling and nose gear doors from scratch to fit the Ravin 500 with the LS1 V8 using West System.. The aircraft has about 40 hours of flight on it i think... Lots of ramp running and and taxi testing.
I did a wet layup and then let the new cowls cure out in a heated metal shed behind my house for a few days. Temps were around 125 during the day, and about 100 at night.. texas summer helped keep it nice and toasty in there.
Even with some over heating issues that the LS1 had before the radiators were enlarged, the cowlings along with the paint (Akzo Nobel single stage urethane) are holding up just fine.