Before applying, the surface must be free of any dirt, dust, oil, grease and any contamination that may interfere with adhesion. Remove loose paint and rust with a wire brush or sandpaper. Remember to mask off any areas that you do not want coated with Undercoating before spraying the product. 

Shake can in an up and down motion vigorously for 1 minute then shake the can side-to-side for 1 minute. At that point, you should be able to hear the mixing ball rattling. If the mixing ball fails to rattle, do not strike the can. Contact Rust-Oleum Product Support using the number on the back of the can’s label. 

For both the standard undercoating and the professional grade undercoating, you should apply 2 coats of product.  After the 1st coat, let the coating dry for 1-2 minutes before applying the 2nd coat. 

The standard undercoating dries to the touch in 30 minutes. It is fully dry in 24 hours. 

The professional grade undercoating dries to the touch in 10 minutes. Allow 72 hours for a full cure. 

Within 1 hour, undercoating paint can be painted over with another color. If you’ve waited longer than an hour, try to apply the paint after 24 hours of the undercoating becoming dry to the touch. Remember to clean the surface before applying the coating if it’s dirty. Do not mix any paint colors into the undercoating.