Powerpoxy "Weld"

Hi,
Been using an epoxy product called powerpoxy Weld I get at a local Farm King, www.powerpoxy.com. Just wondering if anyone else has tried it. I've used it for fins, assembly and epoxy fillets. I know West Systems and Aeropoxy is supposed to be the best I will probably graduate to those systems if and when I go on to larger models. Only problem is it is rated only 250F so I use J and B weld for engine blocks and anything exposed to high temperatures and the resin is black and hardener is gray. Not like J and B. You have to be careful with mixing equal amounts because gray is what the mixed product looks like. In making fillets, I use the masking tape procedure. Apply the powerpoxy. It gels in roughly 15minutes. Remove the tape and I then hit it with a heat gun to remove the sharp edges and I get respectable epoxy fillets. Thanks for any replies.
Kurt Savegnago