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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Aluminum Hand Rails -- Anodizing, Powder Coating, or Clearcoat
Q. Hello,
I am a metalsmith and fabricator in Texas. I am building the aluminum guard and handrails which descend into the whirlpool of this building. I am familiar with the abrasives and equipment I need to achieve the surface condition the client desires, but they then wish to leave the aluminum uncoated. This is a wet chlorine rich environment, how can I expect this raw buffed aluminum to react over time? As an alternative do I lacquer and constantly maintain the project? Do I look into clear anodizing? Is there another protective solution out there I am unaware of? I have no experience with anodizing an architectural project. I have a good deal of bronze finishing experience and very little aluminum finishing expertise. Insight into this issue will be of great benefit to myself and my client.
Thank you,
Metal Smith - Temple, Texas
2004
A. The trace chlorIDE in all tap water will eventually degrade bare aluminum and anodized aluminum. Powder Coat!
Robert H Probert
Robert H Probert Technical Services
Garner, North Carolina
A. Exposed to water, air and chlorine, the aluminum will corrode. Some sort of clear lacquer will hold the corrosion off for a time, but will eventually fail. If you decide to go the lacquer route, the aerosol can stuff will probably not last very long at all. Much better would be a catalyzed polyurethane as used for automotive clearcoat. You can get that from any auto paint store. Anodizing will work well, although in that environment, it won't last forever. Clear anodizing is essentially invisible on some alloys, but can be grayish/yellowish/brownish on other alloys, and welds will anodize differently and will likely be visible. The only 100% satisfactory solution is to make these things out of stainless steel.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
A. The best way would be stainless steel polished to a mirror finish.
Michael Cordell- Texas
A. Should you decide to shoot automotive clearcoat, make sure you first shoot a 1 mil coat of some compound designed to make the clear adhere to bare metal. House of Kolor AP01 ⇦ this on eBay or Amazon [affil links] for example.
Robert Bralliar- Henderson, Nevada
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