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Ted Mooney, P.E. RET
Pine Beach, NJ
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for Metal Finishing since 1989
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Pretreatment (cleaning) process of sand blasted items for hard chrome plating
Q. I would like to install a bath for hard chromium plating. Besides the electrochemical steps, what are the steps of metal treatment before electroplating thank you.
Zerroualuniversity of setif - setif, Algeria
2003
by Robert K. Guffie
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A. The pretreatment depends on what metal you are plating the hard chrome onto, Zerroual. If the parts are steel, probably hot soak cleaning, possibly hydrochloric acid pickling, and probably reverse current etching in chromic acid. If they are cast iron, please see letter 1183. Good luck.
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003
Q. I have a problem in hard chrome process on sand blasted pieces please advise how to clean sand blasted pieces before hard chrome.
Amit Bhardwaj
plating shop employee, - Gurgaon, Haryana & India
September 15, 2010
A. Unfortunately, sand blasting creates a random rough surface that reflects light in all directions. Some of the reflected light interferes with other light waves giving a dull appearance.
To have a bright reflective part, you will need to polish the part.
An alternative is to copper plate and then chrome plate. More likely, the step would be to copper plate and then polish and then chrome (with appropriate cleaning and activation steps)
If you only need a little improvement, try blasting with finer sand, or reblast with very fine sand.
- Navarre, Florida
September 15, 2010
A. You can also re-blast them with glass beads for a pearl like aspect like the one in your photos.
G. Marrufo-Mexico
Monterrey, NL, Mexico
First of two simultaneous responses -- September 17, 2010
A. Dear AMIT,
Firstly are you sure the required finish on the component comes from sand blasting, to me it appears to be glass bead finish.
Secondly as far as your question goes, sand blasted surface does not need any special cleaning if it goes to plating soon after blasting. Be careful of staining the component with finger marks as oil from hands may show up after plating. If at all you get them try a solvent to get rid of them.
Hope it works for you.
ALL THE BEST.
Vikram Dogra
Irusha India - Chandigarh, India
Second of two simultaneous responses -- September 17, 2010
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