Problem Solving Forum
September 4 - September 7, 2018
Are there special primers and surface preparation requirements for painting unpainted aluminum?
Josh Skinner of The Sherwin-Williams Company on
September 24, 2018:
Wash primers, epoxies, and acrylics are excellent ...read more Wash primers, epoxies, and acrylics are excellent choices as a primer for aluminum. Remove all oil, grease, dirt, and oxide per SSPC-SP 1, Solvent Cleaning.
Chris Lucy of chemquest technology institute on
September 12, 2018:
Absolutely. Aluminum oxide is formed on the surfac ...read more Absolutely. Aluminum oxide is formed on the surface instantly upon contact with the atmosphere. Blasting and mechanical preparation will create a surface profile and remove the oxide layer initially; however, it will return within seconds. Coating over the aluminum oxide layer will result in delamination later. As the oxide layer grows, it will force the coating further away from the substrate, especially in salt-laden environments. Chemical removal and deposition of a more passive oxide layer, such as zirconium, will enhance the coating life. There are other methods; however, the deposition of a more stable oxide layer has proven to be the most effective.