However, the elbows were coated in two layers using a hand-held gun. The lining was uneven with the coating up to 25 mils thick. In addition, the elbows were capped after the final coating application and there was insufficient air necessary for curing. A hand-held gun was used to spray the coating because of the shape of the elbow. There are other methods of applying epoxy coatings that are more controllable and use less solvent.
Electrostatic spray uses less epoxy and solvent for the same coating thickness.
Electrodeposition in a water solution provides the most uniform coating and does not use solvents. The fluidized bed method will provide the thickest epoxy deposit. Whatever application method is selected, epoxies are thermo- setting materials and are normally cured by oven baking or infrared heating. Heating reduces curing time from several days to several hours. The repairs were acceptable and a final report was issued in January 1984.