Protective masking for stripping: smart, safer re-anodizing

Summary for protective masking for stripping Discussion

Protective masking for stripping and re-anodizing is the core issue in this thread: Marcello Busini asks how to protect brass inserts in old aluminum parts that cannot be disassembled, since the parts must survive both sodium hydroxide activation and sulfuric acid anodizing. He wonders whether a coating exists that can resist both chemicals, or whether a gentler stripper than caustic soda could be used. In reply, the answerer says the problem has two parts. First, an alternate stripper is chromic-phosphoric acid, which can remove anodizing without attacking aluminum, and the site has more information on it. Second, commercial masking agents from suppliers such as Maskcoat LLC are made to withstand these chemicals. The answer also cautions that masking brass may be harder than it first appears, so the practical challenge is significant even with the right product.