PR-2050 Class B is a rapid curing compound designed for aerodynamic smoothing and gap filling applications. It has a service temperature range of – 65°F (-54°C) to 250°F (121°C), with intermittent exposures up to 400°F (204°C).
This product has low shrinkage and cures to a sandable hardness in at least one hour at 77°F (25°C) or above. When cured, PR-2050 Class B remains flexible, reducing potential cracking problems that can be experienced with more brittle sealing compounds. PR-2050 Class B is a two-part, epoxy cured, Permapol® P-3.1 polythioether compound.
The cured product will not degrade after limited exposure to jet fuel and aviation gas, nor with limited contact to diphosphate ester based hydraulic fluids. PR-2050 Class B exhibits excellent adhesion to a wide variety of properly prepared aircraft surfaces
Immediately before applying compound to metallic, chemically treated, epoxy primed, or urethane primed substrates, the surfaces should be cleaned with solvents to remove contamination such as dirt, grease, and/or processing lubricants.
A progressive cleaning procedure should be employed using appropriate solvents and a new lint-free cloth conforming to AMS 3819. (Reclaimed solvents or tissue paper should not be used.) Always pour solvent on the cloth to avoid contaminating the solvent supply. Wash one small area at a time.
It is important that the surface is dried with a second clean cloth prior to the solvent evaporating to prevent the redeposition of contaminants on the substrate. Substrate composition can vary greatly. This can affect compound adhesion. It is recommended that adhesion characteristics to a specific substrate be determined prior to application on production parts or assemblies