Aircraft Epoxy, Marine Epoxy what's the difference? I am starting the research for building a LongEZ or Cozy Mk IV. The groups and instructions all talk about "Aircraft Rated Epoxy". What's the difference between aircraft and marine epoxies? I understand the stresses are somewhat different, flex and stress vs pounding a 2 - 3,000+ lb boat into crashing waves. I can buy marine epoxy wholesale for $40 per gallon, vs paying retail (from spruce) for aircraft epoxy. Could sure use some help here.