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How to make it brighter

2003

Dear sir,

How to improve the brightness for aluminium alloy when we doing the chemical polish ? The alloy we used is 6 series. How to maintain the brightness when we are having the anodizing bath process ? The question is that after the chemical polish, the shining product will becomes very blur instead. The acid concentration is about 20%, temperature 16C, voltage 12V.

Thank you,

Jarrico
- SSU, Malaysia

If your saying the aluminum is ok after chemical treatment I would set the anodize tank at 12/16 g/l sulfuric acid at a temp. of 68-72 degrees at 12 volts. Depending on the time and coating you need it should be ok after anodizing. You may be to high on sulfuric acid and running to long. This will dull the surface and also cause it to look streaky and cloudy.

Kris Heim
- Walkerton, Indiana
2003

Kris is pretty well on the money with this one. Lower your concentrations of sulfuric. You can anodize from as little as 5%, and relatively speaking it yields lighter color coatings of less thickness, that will not inhibit the brightness of your part as extreme as the 20% solution does. My suggestion is try to move back from 20% to 10%. See how that affects your process, change nothing else beside that. If that shows appreciable differences, then you can try various temperature increases/decreases to get the exact depth of shade and shine you are desiring.

Matthew Stiltner
plating company - Toledo, Ohio
2003