Permatex Form-A-Gasket No. 1 Sealant is a fast drying, hard setting sealant designed for sealing rigid materials and flanges, or patching holes and joints where permanent assembly is desired. Form-A-Gasket No. 1 is resistant to common shop fluids and fuels. For slow-drying option check out Permatex Form-A-Gasket No. 2 Sealant.