Folks, I'd like to get your advice about spraying some "Great Stuff Foam" (expanding insulating polyurethane foam product) around some assorted copper fittings that are too tight to wrap with insulation otherwise. Will this stuff hurt either the copper or the solder? Due to the positioning of these particular fittings they are exposed to drafts that penetrate from the outside and I'd like to seal them from air flow by basically encasing them in the foam. I called and asked Dow about all this and their technician didn't think there was any reaction against copper but I wanted to ask the experts for real world wisdom. I'm sure this is one of those things you see all the time with either good or bad results. Thanks for any advice you have.