Permafil 277 is a unique thixotropic masking agent formulated using duPont krytox. It is used for coating horizontal and vertical surfaces before treatment to aid in the easy removal of a wide variety of cured insulating resins including solventless epoxies and polyesters. - Von Roll 277 Permafil thixotropic masking agent is used on cold or hot parts and compatible with a wide variety of varnishes and resins.