100% Solids Epoxy Performance Testing: Holiday Testing
"Holidays" are bare spots in the protective coating applied to concrete surfaces. Once the coating has set and is hardened, the surface is tested with a high-voltage holiday detector. In order to accurately inspect the work area, the surface must be dry. Before testing, a bare spot or holiday is created on the coated surface to determine the amount of voltage best used to test the coating for holidays in that area. The spark tester is set at a minimum of 100 volts per mil (25 microns) of applied film thickness but may be adjusted as necessary to detect the holiday created for the test (refer to National Association of Corrosion Engineers (NACE International SPO 188-2006). All holidays discovered will be marked for repair. To repair a holiday, the coating surface is abraded with grit disk paper or sanded by hand, depending upon the surface area to be repaired. After the abrasion, the area is cleaned and an additional protective coating is applied by hand over the prepared section. All touch-up and repair procedures follow Quadex, Inc. protective coating manufacturer's recommendations.
