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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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Removal of heavy hard chrome plating from steel cylinder liner
Q. Hello, I'm trying to remove approx. 6-8 thou of hard chrome from a cylinder ID with an area of approx. 80 in ^2. The chrome is plated to a thin steel liner which in turn is pressed into an aluminum body. I would like information on the most "cost effective" way of stripping the chrome with the intent of re-plating. I would also like to minimize any damage to the part in terms of etching or other.
Marc Couturean engineering company - Winnipeg, Manitoba, Canada
2003
A. If you are going to replate it, let the plater do the job. There are at least four alternatives and a conventional chrome shop normally has two. Honing the part in a machine or reverse the cycle in the chrome bath. Also immersion in HCl or anodic treatment in NaOH will strip the chrome, but exposed aluminum will also suffer in both cases and the waste produced will require regulated disposal.
Guillermo MarrufoMonterrey, NL, Mexico
2003
Stripping 10 microns of chrome on steel
Q. Good Day Folks,
I am contemplating setting up a hard chrome plating line. I have everything I need for the most part but was thinking ahead and realize we are going to screw some parts up (if this doesn't tell you I am an experienced plater nothing else will.
I was wondering what the best way to strip approx. 5-15 microns of chrome off a steel pin. The steel is usually induction hardened to anywhere around 45-55 HRc.
In a previous life when I was restoring/replating old car/motorcycle parts we used a sodium hydroxide solution at room temperature with the part being anodic at around 3-6 volts.
I can't remember any of the details and it was mostly for the very thin decorative chrome over nickel. This will be chrome directly plated on polished steel. I would prefer not to harm the steel as it will be someone else's part.
I have in the past for a desperate customer stripped this deposit in my electrocleaner but it took around an hour.
Trent Kaufman
electroplater - Galva, Illinois
June 12, 2019
A.
Nothing wrong with reverse current in NaOH. Cheap, easy and (almost) fool proof.
Inhibited HCl can work too, although there is the possibility of attack of the steel.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
June 17, 2019
Thanks Jeff,
I've been out of it for awhile and wondered if anything had changed.
Thank you for your response.
Trent Kaufman
electroplater - Galva, Illinois
June 19, 2019
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