Many people are intimidated at the thought of attempting to paint their aluminum boat. It is really not a difficult job, but it can be time consuming. Most of the hard work (about 80%) is in the preparation, and the proper preparation is where the success of your paint job will be determined. Appropriate materials and thorough surface cleaning are the most important parts of this task.
Cleaning and painting your aluminum boat will be much easier if you raise it off the ground. Carpenter’s sawhorses are the most convenient way to get the boat to the right height. The boat can be easily flipped to work on the inside or the outside.
The first step in the preparation for painting is sanding or stripping. Some people like to strip off old paint, but the stripping chemicals are highly toxic to both people and the environment, and protective equipment such as goggles and gloves will be required. It is only necessary to sand off any loose paint and scuff up the rest so that the new paint can adhere to it. There is no need to sand down to the bare metal. A light sanding over the entire surface is a good idea. An electric sander or a hand sanding block can be used.
Once the sanding or stripping has been completed, the second step is a thorough cleaning. Paint does not stick to dirt, metal shavings or any other loose debris. You can use a bucket of soap and water, along with a stiff bristle brush. Follow-up by rinsing with the water hose until all traces of soap have been removed. (A power sprayer can make short work of rinsing.) Allow the boat’s surface to dry completely.
The third step is applying primer. Painting and priming are best done outside. Both are toxic, and require plenty of ventilation. Use a primer that is specifically designed to be used on aluminum oxide surfaces. Apply the primer according to manufacturer’s instructions in order to achieve the best results. Primer can be applied with a brush or roller, but if you want a smoother more professional looking final result a sprayer should be used. Allow the primer to dry completely before applying the actual paint.
The fourth step is the actual paint. Choose your paint carefully; epoxy takes a very long time to harden sufficiently; possibly weeks, before you can use the boat. Some people choose automotive acrylic paint. Just make sure that whatever paint you use is a water resistant variety. Check with a boating supply company about using marine paint. For the deepest, richest paint color, you will likely need to use two coats of paint. Let the paint completely dry between coats.
The fifth and final step is clear coat. Clear coat makes the paint shiny and protects it from scratches and dings. It also helps your new paint job last far longer. If you are doing a treatment such as camouflage, you may not want the paint to be shiny. However, be prepared to re-paint much more often if you elect not to use clear coat. Clear coat is applied in exactly the same manner as the primer and paint.
Tip: Always apply paint with a sprayer in several thin coats, in broad sweeping strokes to avoid runs and drips.