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Can't reliably zinc plate stress proof material

We are having trouble plating stress proof material 1144, in cyanide zinc bath, parts just seem to tumble in barrel and not plate, tank plates everything else fine what can we do, sometimes it plates and other times doesn't. Is it the material?

thanks

ED COLEY
PLATER - WINTERVILLE, N.C., USA
January 8, 2008

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First of two simultaneous responses -- January 10, 2008

Ed,
I m not totally sure what the alloy/treatment which you are calling stress proof material is. I do know that certain alloys and heat treated steels will not readily plate in cyanide zinc due to high hydrogen overvoltage.

One old time platers trick, when cyanide cadmium baths were widely used, was to strike in the Cd bath before cyanide zinc. You might want to consider something similar if you have other plating solutions available i.e. copper, nickel, etc.

Gene Packman
process supplier - Great Neck, New York

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Second of two simultaneous responses --

1144 to me is a steel and with that much carbon, what else does it have to make it "stress proof". That something else is very important as you normally can plate anything but leaded parts in cyanide baths.

James Watts
- Navarre, Florida
January 10, 2008

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January 16, 2008

Ed.

My God....
Having recovered from the shock of hearing you still plate out of an outdated, and EPA prone Cyanide zinc solution...
let me make life easy by telling you how to get that " Stress " out of your life.

Follow this sequence.

1) Soak Clean in Hote soak cleaner to remove oils.Dirt .
2) Rinse well x 2 times . City water.
3) Use an inhibited pickle to remove the light rust and don't leave parts just sitting there. Get them out when the rust has gone.
Use a Inhibitor in the Hydrochloric acid. thats the inhibited pickle.
4)Rinse well x 2 times. City water.
5) Anodic Clean the Parts in a simple caustic soda [affil links] solution at 150 Grams / liter @ 50 centigrade for 5 - 7 minutes @ 10 to 12 volts. don't use a proprietary cleaner.
6) Dip in caustic soda [affil links] solution 100 Grams / liter.
7) Plate in your Cyanide solution. The composition should be around Medium to High Cyanide.
8) Dragout x 2 times.
9) Rinse well x 3 times.
10) 0.5 % Nitric dip.
11) passivate.....Rinsex 3 times and dry.

The anodic cleaner will remove the oxides that prevent plating. Keep it hot and keep it clean.

Regards
Asif Nurie

Asif Nurie [deceased]
- New Delhi, India
With deep regret we sadly advise that Asif passed away on Jan 24, 2016

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February 20, 2008

Hello Ed,

After the pickling step just soak the parts overnight in 50 g/l of sodium cyanide, the parts will plate beautifully the next day.

Khozem Vahaanwala
Saify Ind

Bengaluru, Karnataka, India