When a good idea goes bad

An American tobacco company used the warehouse buildings for the fumigation of the tobacco, during which the entire interior of the building is filled with a gaseous insecticide that kills tobacco-damaging insects. The company chose to completely seal the building using a polyurea coating system as once the fumigation chemicals escaped. The system chosen for application consisted a one-coat epoxy primer, followed by a coat of the polyurea product and a polyurethane topcoat. The 100% solids polyurea material, a two-component coating with a one-to-one mix ratio and a dry-to-touch time of 45 seconds, was designed to bridge cracks up to 1/8-inch wide. Several problems arose during the coating application to the exterior of the fumigation building. A site visit was scheduled by an independent coatings consultant to examine the walls of the subject fumigation building. The examinations disclosed that the coating system consisted of a bluish-gray brittle topcoat with underlying flexible gray coats and an intermittent yellow translucent brittle coating.