Painting Over Aluminum
Problems: There are many types and grades of aluminum. Some are easier to paint then others,
It's always best if you know the grade of aluminum first. The key to painting aluminum is
painting BEFORE the aluminum produces it's “self healing” barrier coating. Among other
attributes, marine-grade aluminum alloys, those in the 5000 and 6000 series, are naturally
corrosion resistant. When exposed to air, oxygenated seawater, or fresh water, aluminum quickly
develops a tough, transparent oxide film that is resistant to corrosion. This happens VERY
QUICKLY! In fact this oxidation can occur within 3 hours of cleaning and sandingThere is,
however, an aesthetic price for this durability. Left to the elements, aluminum develops a dull
gray—and eventually dusty, gritty—finish; for military, pilot, fishing, and utilitarian
applications, that finish can be a thing of beauty, as it lowers building and maintenance costs.
Few recreational users have, however, learned to look beyond aluminum’s blemished surface.
The Key then is to prime over the bare cleaned aluminum BEFORE it re-oxidizes!
Wash a mild detergent dish soap. Mix a cup of soap to three gallons of water in a bucket. Use a fiber
washing mitt to scrub the surface thoroughly. Remove all light oxidation, oil and fingerprints. Rinse
completely and let air dry.
Sand with 220-grit sandpaper.
Tip: Wrapping the sandpaper around a stiff sponge sanding block allows you to follow the curves of
the what you are painting without cutting into the sharp edges.
Wipe down all sanding residue with towels and Tamco HR-397 Wax and Grease remover. Do this in
sections, and change towels frequently. Wipe down until you see little or no color on the towels. If you
discover any flaking on the hull's surface, like old clear coat, re-sand the area until it's gone.
Immediately mix your primer. Tamco DTA is the very best primer sealer for aluminum, and it is
WATERPROOF! However, Tamco's HP-5310 series Urethane Primer can also be used, as well
as Tamco's Foreverseal 1K sealer and Tamco HP 770 series High Build primers. The key is to
have this product ready to use as soon after sanding and cleaning as possible!
DO NOT USE AND ALUMI-PREP's with Under Tamco Primers!
If using DTA----Allow 3-5 Days Cure time before putting into service
Written By: Bob Barney
Tech Dept (800) 678 1533 Press #5 for more help