In the 1880's, European entrepreneurs discovered how to separate aluminum from the mineral bauxite, and the glory of aluminum crumpled (pardon the pun). The former precious metal is now associated with pop-top cans, recycling campaigns, and that project that's been lingering on your Honey-Do list: Painting your aluminum siding.
Prior to vinyl, aluminum was the go-to choice for affordability and durability. Lots of houses were clad in aluminum during the 1940s to the 1970s. Contemporary homes often use industrial materials, like aluminum or fiber cement or galvanized steel, as decorative siding.
And with your luck, it's chalky, pitted, corroded, peeling and molding.
So get scrubbing.
Exposed aluminum does not rust; it corrodes. Oxidation creates a crusty gray chalk, which is literally eating your siding for lunch. Purchase an aluminum cleaning liquid or concoct your own using detergent or a mixture of water/trisodium phosphate, and apply a thin coat. Wait 10 minutes, and then swab the surface with a soft-bristled brush like a car detailing brush.
Notice any small white spots? That could be mildew. Hose down the siding with a bleach/water or vinegar/water mixture, and then let the siding dry. Do yourself a favor and rent a pressure washer. Then clean like Cinderella until the metal glistens, sheds water in sheets, and has no chalk.
Such is the process for preparing naked aluminum. But what about siding previously painted?
First, launch an offensive against peeling and blistered paint with a putty knife and sander with fine-grit paper. Get rid of any loose paint.
Don't ignore that paragraph! NO LOOSE PAINT. NO CHALK. NO WAX. A clean surface can double the lifespan of your finish coat.
After cleaning and sanding previously painted aluminum siding, you probably need to prime it. A zinc oxide primer inhibits corrosion and mildew. Oil-based primers soak up chalk, but most latex primers will bubble when applied over naked aluminum. Some exterior enamels don’t even need primer.
Again, do yourself a favor, and apply paints and primers using an airless pressure sprayer with a 415 or 515 tip.
After priming, apply the finish coat, something like Sherman Williams Duration or Benjamin Moore Moorgard. We recommend low-sheen finishes with self-leveling technology. Use latex paint, since oil paints tend to crack. Choose lighter colors to prevent buckling.
If this sounds like a lot to remember – well, it is. And the good news is that you don't have to. At Brad Stoner Painting, we do all the work, both mental and physical. You just sit back. Relax. Go admire your aluminum cutlery.
