HOW TO STRIP OLD ANODIZING OFF FOR A NEW COAT
I'M LOOKING TO ANODIZE A PAINTBALL MARKER BARREL THAT IS ALREADY ANODIZED BLACK. HOW DO I TAKE OFF THE BLACK ANODIZING WITHOUT SANDING IT? IS THERE A CHEMICAL THAT WILL TAKE IT OFF OR DO I HAVE TO SAND?
PLEASE HELP ME OUT.
USMC - HAVELOCK, North Carolina
You can remove anodizing with a strong solution of lye or oven cleaner. These are very dangerous chemicals, though, which an amateur really shouldn't use. Further, they attack the aluminum as well as the anodized coating, so they must be removed ar the right time.
A professional would use a mix of phosphoric and chromic acid (if you search our site you will find letters describing the exact mix and operating conditions) which will remove the coating without attacking the aluminum. It's really best to take it to a plating or anodizing shop; they will do it effortlessly, safely, and with proper handling of the wate products.
Ted Mooney, P.E.
Pine Beach, New Jersey
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