Corsair, if we knew exactly what task you are performing we would be able to suggest the correct product. In my case I keep a gallon of laminating epoxy around. I use it in its original form for glassing wood parts, laying up fiberglass parts and such. When I need some epoxy (glue) I mix up some laminating resin and add some milled fiber and cabosil until I get the consistency I want. Polyester resins never make it into my shop.