Steel Garage Doors
Have you ever been asked, "When it's time to repaint my garage door, what type of paint should I use?" or "What preparations need to be made before repainting my garage door?". The following instructions will answer these and other questions you may have been asked about proper painting practices for steel garage doors.
- First and foremost, any garage door surface that is going to be repainted must be properly
prepared to assure the continued performance of the coating system. Therefore it is necessary to
clean the painted surface. The following are recommended levels of detergents or household
ammonia to use:
One cup of Tide, or other common detergents which contain less than 0.5% phosphate, dissolved into five gallons of warm water. NEVER BLEND CLEANSERS OR DETERGENTS WITH BLEACH.
One cup of household ammonia dissolved into five gallons of water (room temperature).
The garage door may be washed with either solution. The use of a well-soaked cloth, sponge, brush (with very soft bristles) or low pressure spray washer is recommended. Once the door is washed, thoroughly rinse with clean water to eliminate the possibility of residue. - Surface imperfections such as minor scratches, which have not left the metal substrate exposed, can be lightly sanded or buffed to create a smoother surface. Care must be taken, however, not to expose the substrate. Rusting is greatly increased when the metal substrate is exposed.
- Exposed metal must be treated to prevent rust from forming. To do so, sand the general area lightly and use a primer* specifically designed to protect any exposed galvanized steel from corrosion.
- After the door has been properly prepared, it must be coated within 24 hours with a high-quality latex exterior house paint. The paint must be thoroughly mixed before using. Mechanical mixing is recommended to assure that no settling on the bottom of the container remains.
- The surface must be completely dry prior to painting. Painting should be done in the early morning. Avoid painting when temperatures are below 50 degrees Fahrenheit. Apply a uniform coat at the manufacturer's recommended dry film thickness.
The above instructions are only a generalized summation of proper painting practices and in no way cover all aspects of repainting steel garage doors.
*Glidden Galvanized Metal Primer 5229, PPG Galvanized Steel Primer #6-209, or equivalent primers specifically designed for galvanized steel surfaces.
