How to Paint an Aluminum Garage Door

A new aluminum garage door with the sunrise reflecting off of the white surface.
  • 2-4 hours
  • Beginner
  • 250-550
What You'll Need
Firm-bristled scrubbing brush
Warm soapy water
Drop cloths
Oil-based primer (brush on or spray)
Solvent or turpentine
Paint brush
Oil-based or acrylic exterior paint Gloves
Eye protection

If the look of your aluminum garage door has become dull and old, you may be considering ways to give it a new life and a polished look without replacing it altogether. You can achieve this quite easily and cheaply with a simple coat of paint.

Cleaning the Door

The garage door needs to be totally clean before you begin preparing to paint. In order to produce an excellent surface for the primer, the aluminum will have to be free of dirt and dust or else it will interfere with adhesion.

Remove any loose particles with a firm-bristled brush, and use the warm soapy water to clean the door and scrub off any loose parts that chip away from the surface. Aluminum doesn’t oxidize, but the factory finish can deteriorate.

Preparing the Door

It is always a good idea to not paint outside objects in extremely wet, cold, or hot conditions. Metals and alloys still expand in the hot air and retain heat, so the paint will not dry to the highest standard that you would expect. Therefore, when planning this project, try to aim for a string of mild, clear days to achieve the best results.

To avoid having to hunch over as you work, start painting your door from the bottom up, beginning with the door halfway open so you only have to lower it to the ground to move upward. Obviously, once you can’t lower the door anymore, you will have to use a ladder to cover the rest. You’ll also want to lay a drop cloth on the ground below the edge of the door to prevent any wayward drips from falling onto your concrete.

Once the door has been washed and dried you can begin painting the primer coat. It is recommended that you thin oil-based primer just a little by mixing in some paint solvent according to the manufacturer’s instructions. Leave the primer to set for at least 24 hours. You can also use a spray primer suitable for aluminum but make sure to mask off areas that you do not want to be painted.

Painting the Door

After the 24-hour drying time has elapsed, you can paint the top coat on your garage door. Oil-Based exterior paint is a good choice for going over an oil-based primer, but a 100 percent acrylic exterior paint can also be suitable.

Use a large brush to cut down on your overall painting time. You can use a roller but they are much harder to clean if you use oil-based paint, so a brush is usually a better option. How you direct the brush depends a lot on the type of garage door you have. There is no grain to follow, like with wood, but you will no doubt want to paint the garage to leave as few stroke marks as possible. Leave that first coat to dry thoroughly.

Applying the Second Coat

The first coat needs to be completely dry before you apply a second. You may find that some parts of the door look a little patchy or blotchy but a solid application of the second coat should cure that and even out the coverage for a uniform surface appearance.

Cleaning the Brushes

After you’ve finished, your brushes will need to be cleaned properly using a solvent like turpentine, white spirit, or paint thinner. With oil-based paint you cannot use soap and water like you can with acrylic latex, so dip the brush in plenty of paint solvent until all the residual paint has come out. Once it is all gone, you can then use a thick solution of liquid dish soap to finish the cleaning.