What is this gray goo? I was out getting gas and spied some tires in a pile. I went over to inspect and saw the tires were very worn discards, Upon closer inspection I saw that the tires had "Tire treas patches" glued onto the side ares that had wear with a VERY hard gray adhesive. Quite interesting! While obviously such patching isn't recommend over such a weak area that the side wall is, in an emergency just knowing about such an alternative might be the key to surviving a bad situation. So what is that gray goo? I've asked around and no one knows....