How do I remove old, stuck-on gasket material from flanges?

Never scrape off old gaskets with a razor blade or anything that can scratch the metal surfaces and create a leak path. Doing so may compromise the seal and the operation of the assembly. But failure to clean off old gasket or gasket materials may result in the mating surfaces coming together in an uneven alignment. Instead, use a plastic scraper or nylon brush. View our CNA sheet gaskets.