If you do happen to find Formula U, stay away from it. I recently sprayed a set of floats for my plane with a can of "u" about a month ago; ran out about half-way through the project, went back down to the LHS only to find out "they no longer produce or stock it." I caught pure hell trying to figure out compatibility. And to top it off, the finish really looked like doodey, and I'm no rookie. I had the misfortune of tearing up one of the floats, only to discover the formula u DID NOT stick to the underlying primer...in fact, it peeled off with a pocket knife blade like a banana peel. STAY AWAY FROM IT!!