Bright dipping aluminum produces Nitrogen Dioxide, a toxic orange fume, due to the Nitric Acid that is required in the bright dip bath. These fumes cling to the rack of parts as they are pulled out of the tank requiring an expensive shrouded hood. Also, because of the high bath temperature, 210-240F required and the fact that Nitric Acid is volatile, plant corrosion is extensive. The bright dip bath also has about 17 variables that have to be controlled to produce good work.
Extensive analysis is needed during the operation hours to keep the bath parameters in check.
The aluminum being bright dipped is not deburred and leveling of the surface is minimal at best. The aluminum parts on the rack are leveled and deburred due to the current density used in this process. A rectifier with 24-40 volts DC is used. Electropolishing time can be 1-10 minutes, depending on the size, shape and other parameters. Aluminum parts that are electropolished and kept wet prior to anodizing do not produce a vale or slight haze when anodized.