What Went Wrong? Military Tank Farm Failure

Paint FailureThe government awarded a painting contract to clean and paint the exterior of a steel fuel tank on a remote military tank farm. Work was carried out in the summer. The apparent preparation work consisted of solvent cleaning to SSPC-SP1 and hand cleaning to SSPC-SP2. According to the information received, all work was carried out in accordance with the specifications. The contractor maintained that all cleaning and painting work was carried out within the environmental requirements.

Nevertheless within months, the paint coating was blistering and peeling. A technical consultant was flown into the area to have a closer look. Although the contractor had assured all parties that the coating was applied in acceptable environmental conditions, a microscopic evaluation revealed pinholes and that moisture drops had lodged on the paint film before the coating was dry, as is shown in this photograph. The conclusion was that insufficient preparation work had been done. Priming was done sparingly, and top coat application varied from 1 to 2 mils dry film thickness. Sparingly prepared surfaces and applied coatings, in combination with wet surfaces at the time of the coating application led to the failure.