Tips for Painting Aluminum Siding
Can You Paint Aluminum Siding?
The factory finish on aluminum siding eventually fades from the sun and needs to be painted. Painting aluminum siding is actually quite easy and usually takes less time than wood siding. Unlike porous wood, metal siding is smooth and can be spray painted without having to roll the paint.
Aluminum requires thorough preparation before it can be painted. When the surface is prepared correctly, the paint on aluminum will last much longer than wood. I spray painted the metal siding on my house many years ago and the paint shows no signs of failure.
Best Paint for Aluminum Siding
Not all exterior paints can be applied to aluminum siding. The paint should be acrylic, and the label on the back should indicate it can be used on aluminum.
There are several exterior paints on the market that can be used on metal. The following paints are products I have used for painting aluminum siding:
- Pittsburgh Manor Hall (Pittsburgh Paints)
- Super Paint (Sherwin Williams)
- Duration (Sherwin Williams)
I spray painted my aluminum siding with Pittsburgh Manor Hall over ten years ago and the paint has held up fine. On clients homes, I have used Super Paint and Duration with great results. Both paints are self-priming and provide excellent coverage. Two coats of paint is best.
I recommend buying siding paint in a satin finish so it's easier to clean dirt accumulation on the surface. The gloss of a satin finish also looks similar to the original factory finish of the siding. If the siding is riddled with dents though, flat paint will do a better job at hiding the damaged areas. The key to painting siding successfully is preparation. Any paint will fail if the surface isn't prepared correctly.
Apply Siding Cleaner
A chalky film develops on the surface of aluminum siding that needs to be cleaned so paint sticks better to the metal. Even if the siding isn't chalking, the surface should be cleaned anyway to remove dirt and residue.
An effective method for cleaning metal siding is with the cleaning agent trisodium phosphate (TSP). You can purchase the cleaner in powder or liquid form. Although TSP is a great cleaner, the material can damage plants and grass. Before applying TSP, spray your flowers with water from the garden hose. Covering flowers with plastic tarps is also a good idea. An alternative cleaner to TSP is a product called Simple Green, which won't harm plants.
Power washing siding is the fastest and most effective way to clean the surface for paint. Some power washers have a chemical tank that allows you to siphon a cleaner through the machine first, or you can use a garden sprayer to apply the material and wash it off with a garden hose.
Priming Aluminum Siding
Priming is necessary if bare aluminum is exposed, or if the surface is terribly weathered and peeling from a previous paint job. But if the siding finish is only faded from the sun, primer isn't needed, using two coats of quality acrylic paint.
If priming is needed, an acrylic primer is best. If the surface is peeling then sanding is required before applying primer.
How to Spray Paint Aluminum
The best way to paint aluminum siding is with an airless sprayer. Brushing and rolling takes too long and doesn't look as nice as a sprayed finish. If you don't already own an airless sprayer, rentals are usually available at the paint store.
Before spraying paint, windows must be masked with tape and plastic first. The fastest way to mask windows is with a hand held masking machine. The tool allows the tape and plastic to be applied to the window at the same time. The plastic comes in a small roll that unfolds after being taped to the surface.
Flower beds and grass should also be covered carefully with drop cloths to prevent exposure to over-spray. Soffits also need to be masked too if they won't be sprayed.
When spray painting siding, always start at the top and work your way down to the bottom. To achieve an even paint finish, without visible flash marks, spray the siding from one side of the wall to the other side. Never start spraying in the middle of the siding. Angle the spray gun upwards to coat the narrow edge of each siding piece.
To minimize over-spray, use a smaller spray tip and turn the pressure down on the sprayer. Two coats of paint is best for durability.