PR-188 is a sealant adhesion promoter that is suitable for use with both PRC® and Pro-Seal™ brand sealants. This product enhances the adhesion of both polysulfide, and Permapol® polythioether based sealants to standard aerospace substrates.
This product is fully qualified to the AMS 3100 Class 2 specification. It has zero VOC’s as currently defined by U.S. environmental regulations. PR-188 is a onepart compound suitable for application by brush or clean gauze. PR-188 is not appropriate for use on polycarbonate or acrylic substrates.
Immediately before applying adhesion promoter to substrates, the surfaces should be cleaned with solvents. Contaminants such as dirt, grease, and/or processing lubricants must be removed prior to adhesion promoter application.
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.
Apply a thin coat of PR-188 to the solvent-cleaned surface with clean gauze and allow to dry for approximately 30 minutes at standard temperature. After drying time, wipe off excess PR-188 with a clean gauze pad and start the sealant procedure. If surface becomes contaminated or sealing is not accomplished with 4 hours after application of the adhesion promoter, repeat priming procedure.