Most homeowners choose metal garage doors over wood or vinyl models because they're looking for both durability and longevity. However, that goal can backfire if the paint or coating begins peeling and flaking off after just a few years of use. Find out what's causing your paint to fail and how to correct the problem so the next coat doesn't fall prey to the same problems.
The Causes of Garage Door Paint Failure
Whether the door is covered in basic exterior paint or a complex epoxy coating, the same issues can result in a poor bond. It's a weak bond that causes the coating to peel off far before its time. Small mistakes that interfere with bonding include
- Leftover protective coatings that keep the metal from rusting or corroding before it can be painted
- Residual oil left behind after the sheet metal pressing and polishing process
- Mismatched paints and metals, such as oil paint paired with galvanized metal
- Oxidization that formed on the metal due to a delay before paint was applied
- Layers of primer and paint that were applied before each application fully dried and cured
- Missing primer, especially on galvanized metal or aluminum
- Mixed paint types, such as acrylic-based mixtures applied over a coating of oil paint
- Exposure to extreme weather conditions, like direct sun for 12 hours a day or constant rain storms beating directly against the surface.
Aside from the last cause of paint damage, you can deal with the rest of these problems simply by taking more care when adding the new layer of paint.
Preparing the Peeling Surface
First, you'll need to remove all the loose paint on the garage door. There's no need to remove every trace of the previous coatings if the problem arose due to weather or improper curing, but other problems like a lack of primer, layers of oil or oxidation, and mismatched coatings are best handled with complete resurfacing. Focus on taking off all the bubbling, flaking, or peeling areas if you're not buffing down the entire door. Try a large grit sandpaper block or steel wire brush for small areas and a grinder wheel for resurfacing the entire door.
Removing Grease and Other Coatings
If you suspect the paint failed to bond because the underlying metal has a white powdery coating or feels greasy, you'll need to remove all the paint and get rid of that layer before adding any addition coatings. This is a big project, so you'll likely need to leave it to a professional in garage door repair and restoration instead. If your garage door is still within its warranty period, consider contacting the manufacturer for a replacement since applying a factory coating over a layer of oil is a mistake on their part. Buff off any rust or white corrosion too.
Scouring Raw Metal
Relatively clean metal still benefits from the application of a degreasing cleaner and some scouring. Metal degreasers do a good job of removing dirt, mildew, and other debris that cause paint to peel just as much as oil and grease. Don't be afraid of scratching or scuffing the sheet metal since a roughened surface only encourages the paint to cling even better.
Choosing and Applying the Paint
Finally, pick your paint and either spray it on with a rented sprayer or use a soft napped roller. Brushes leave obvious marks when used over sheet metal surfaces, as well as extending the amount of time it takes to cover a large garage door. Latex and acrylic based primers and paints usually work best for all types of metal garage doors, but you'll need to stick with oil if that's what is already on the surface. Consider hiring a repair technician, such as AR-BE Garage Doors and Openers, to apply a powder coating or epoxy instead, since these options last longer than basic exterior paints.