Painting Aluminum Tubes

Q. I manage finishing operations for my company, and in our product line we have an aluminum tube being used as an extension for a carbon mast. We have been painting this tube with white paint, but are having problems with the paint’s durability, as it is chipping. The surface would need to be scratch- and abrasion-resistant. This aluminum part will also see marine exposure as it will be used in water sports. Since anodizing in white isn’t an option, what other options could you suggest? D.B.

 

A. The proper selection of coating and pretreatments for marine exposure is extremely important. For marine exposure, both fresh water and salt water, epoxy coatings are recommended and have been used extensively for decades. I recommend pretreating the aluminum pole by anodizing. This will provide an excellent paint substrate. Prime the anodized aluminum with a two-component epoxy primer. Topcoat the primer using white two-component epoxy enamel. Although polyurethanes as well as other weather- and abrasion-resistant enamels would be just as durable.