Polyflex FR is a fire-resistant impregnation resin from IMPCO Inc., East Providence, RI, for sealing electronic connectors, wires, and wiring assemblies against corrosion. A traditional solution has been to impregnate components with thermoset resins. Unfortunately, these tended to ignite when exposed to fire. Polyflex FR protects electrical components from corrosion and makes them fire-resistant. Cured by heat at temperatures below thresholds of sensitive components, the resin is irreversibly cross-linked and will not reliquify, melt, or burn. The resin does not require any special ventilation or special handling during use. It is not an epoxy and so has a long pot life when properly stored.