POR-15 Patch Tube Sealer Rust tank RepairPOR 15 Patch, 4oz tube. For years, POR 15 customers have asked for a thicker version of their world famous POR 15 for filling in seams or holes. Here it is! POR Patch is, quite literally, POR 15 in a tube. Like POR 15, it dries as hard as a rock, remains flexible, and once dry, is totally impervious to fuels and solvents. It's so tough that it actually adds strength to weakened metal and it won't absorb moisture and swell like conventional body