It can be applied to rusted, painted, damp, and bare metal. No sandblasting required. Remove all debris, soap, and degreaser from the metal surface. To ensure long-lasting protection of corroded or previously coated surfaces, a wire brush may be used to remove all or most loose corrosion. We do not recommend a paint topcoat over the top of HD Corrosion Shield. 

For best results, apply when surface temperatures are between 41F and 99F (5°C – 37°C). Apply a thicker coat over known problem areas, edges, cracks, and welds. Extremely old, porous metal may require a thicker-than-normal layer due to the product's tendency to penetrate deep.