Validation of Hazardous Air Pollutant (HAP)-Free Torque Seal Inspection Lacquer

The Army uses numerous adhesives and sealants, among other coating materials, that contain significant amounts of hazardous air pollutants (HAPs). This work examines laboratory and field demonstration/validation of one sealant, Torque Seal. A HAP-free alternative to Torque Seal containing ethanol as the carrier solvent has been identified. Laboratory testing including adhesion, resistance to fluids, resistance to humidity, and drying time validated that the HAP-free sealant performs very similarly to the baseline Torque Seal containing methanol (HAP). Furthermore, a demonstration study at Fort Rucker, AL, using a UH-1 helicopter rotor, shows that the HAP-free sealant performed as well as the Torque Seal.