Letter 29075

Etching in anodizing  

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Is etching necessary for anodizing castings. The castings are chemically washed before it goes for anodizing. Need this for deciding my process sequence for my new plant

Thickness: 20 microns
Hardness : 340 Vickers

S.Jabasingh Immanuel
Anodizing shop - Chennai, Tamilnadu, India

Gm,

Etching in Chromic / Sulphuric is required prior to Anodising to remove and even out surface imperfections eventhough alkaline degreasing to some extent etches the surface of Aluminium. Also, a Dip in chromic/sulphuric bath will help in removing the smut formed on the surface during Alkaline Degreasing.

Shankaranarayanan N
- Bangalore, Karnataka, India

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