Since 1989: Education, Aloha, & the
most fun you can have in finishing
Problem? Solution? Chime right in! (perhaps the world's last 'no registration' site)
"Black spots on electro-gold colored anodized aluminum"
November 16, 2018
Q. Dear adviser,
I am working on Al 6063 alloy. I have a titanium salt based electro-gold color tank, where I maintain the following parameters:
Gold-salt= 4-5g/l, H2SO4=15-17 g/l, Temperature= 57-60 °C, required time= 3.0-5.30 min. Recently I'm facing a problem that showing a black spot on gold color surface after Ni-based cold sealing. It appeared between the flat profile when it is wrapped and 3-4 days later. Also appears a white powdery layer when two flat surface profile attached/bundled by wrapping paper. Please advise me how can I solve it.
Disclaimer: It's not possible to fully diagnose a finishing problem or the hazards of an operation via these pages. All information presented is for general reference and does not represent a professional opinion nor the policy of an author's employer. The internet is largely anonymous & unvetted; some names may be fictitious and some recommendations might be harmful.
If you are seeking a product or service related to metal finishing, please check these Directories: