plating, anodizing, & finishing Q&As since 1989
Etching aluminum with a matte surface
Dear sir or lady:
Please let me know what is the formula to reach a satin finish for aluminum parts? I have been trying caustic soda etchant according to this formulation: 50% NaOH 4% sodium gluconate 1% sodium sulfide 25% TEA(triethanolamine) 0.1% ammonium persulphate reminder water but the final appearance is not what I need, I need a opaque and uniform surface aluminum profile after etching process.
If any one can help me I would appreciate very much! "thanks a lot"
- Isfahan, Isfahan, Iran
Try ammonium bi-fluoride at 1/2 to 1 oz per gal room temp after a good cleaner
Drew Nosti, CEF
Ladson, South Carolina
You may try the following formulation and operation parameters:
Free NaOH = 50 g/l
Aluminum content = 28 g/l (with Caustic soda recovery system) or 130 g/l with long life additives
(mainly sodium gluconate)
Temperature = 50 - 55 °C
Etching time = 10 - 13 minute
What aluminum alloy you are referring to, 6063. 6061 ...
- Selangor, Malaysia