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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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Chrome plating a bumper with lead filler? Is brazing better?
Q. Hello everyone.
I need to know if it is possible chrome a steel bumper that has some lead filler on it. Thanks a lot for everyone's input.
Aaron Petermetal fabrication - Rochester, Indiana, USA
2004
A. Yes, it's possible; however, very few shops will be able to plate over the combination of lead and steel. Much better to straighten, polish and buff and replate without any lead.
Jeffrey Holmes, CEF
Spartanburg, South Carolina
2004
2004
A. I think that plating a steel bumper with lead filling is going to be a tough task. The cleaning and pretreatment processes are completely different. In fact, most plating shops are not going to have a pretreatment for lead. Consequently, you run a high risk of adhesion problems because if you clean the steel properly, you will probably damage the lead. Conversely, if you clean the lead, it may not be aggressive enough to properly clean the steel. Reworked bumpers are typically brazed with brass as opposed to lead repair. I'd replace the lead with brazing and you'll be off to the show.
Good luck!
Daryl Spindler, CEF
decorative nickel-chrome plating - Greenbrier, Tennessee
A. The previous responses are correct. The pretreatment to get correct plating adhesion for lead alloys is far different than for mild steel. Rather than attempting to repair the bumper yourself, use a plating shop that does restoration and will properly fill, grind and polish so that the plating may be done correctly. In the end, this approach will probably not cost more than finding someone to plate what you have correctly.
Gene Packmanprocess supplier - Great Neck, New York
2004
Q. Hi,
I custom form and shape car bumpers, etc., with a lot of cutting , welding and grinding. Can I use silicon bronze to fill small low spots and voids? Will the chrome shop have any trouble plating copper, nickel, and chrome over this? I have read some people use silver solder or even lead to fill low spots. Also how thick can my plating shop go with the copper plate, because I want to block sand it to get it perfectly smooth. Thanks, pat.
custom car builders - Riverside, California, USA
March 19, 2013
A. Hi Pat. We appended your inquiry to a thread where several professionals tell us that brazing would be much better than other fillers, and that has been my experience as well.
There is no real limit to the copper plating thickness: wave guides with walls 1/4" thick are electroformed from copper. But the time required in the copper plating tank, and the risk of something going wrong, is in proportion to the thickness -- so it's best to hold it to a couple thousandths of an inch if you can or the cost may get prohibitive.
Regards,
Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
March 22, 2013
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