Sound technical content, curated with aloha by
Ted Mooney, P.E. RET
Pine Beach, NJ

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Problem of chromium 3

2006

I prepared chroming electrolyte.
But it isn't working
270 g/l CrO3
2,8 g/l H2SO4
Surface is milky and not bright
I use platinised titanium anode basket and lead rod
Can you help me, please?

Fikret MUTLU
- Izmir - Turkey

The subject of your letter doesn't match the body, Fikret. "Chromium 3" is slang for trivalent chromium, but the CrO3 you are using is hexavalent chromium.

You should use solid lead as the anode material; I don't see the role of titanium anode baskets here. What temperature and current density did you try? What happens when you try a Hull Cell? What chrome plating books do you have access to? Thanks.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2006

2006

Dear Fikret
high temperature -low current ---milky chrome
low temperature--high current-----grey chrome
if you are doing hard chrome try 55 °C and around 30amp/sq dm. For decorative use the same temperature and current 5-8 amp/sqdm.
Good luck

Khair Shishani
aircraft maintenance - Al Ain, UAE

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