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Painting over chrome

I have a bumper on my Jeep CJ7 that is chrome that I would like to paint a gloss black...The chrome is in good shape all but the welds there kinda rusty (not to bad though)..Is there any way I could paint this bumper without taking it to the body shops and spending a lot of $$ on it.

Thanks,

Phillip Chapman
Hobbyist - Hazlehurst, Georgia, USA
2004

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A 'chrome bumper' is actually a steel bumper that has been nickel plated and then chromium plated. Chrome is notorious for poor paintability. Most paints will not "wet" it, and will not adhere at all. If you were to strip the chrome, and then roughen the nickel with fine sandpaper, I believe the paint would stick good enough to satisfy most people.

Stripping the chrome with hydrochloric acid is fast and effective, but dangerous, and leaves you with acid to dispose of. It would be best to have a plating shop strip it for you. They could also strip the nickel (which you cannot do yourself), getting your bumper down to bare steel if you wish.

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
2003

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October 29, 2009

Hi

I have the hydrochloric acid and need some advice on how to go ahead with the stripping . my bike wheels are rusted/pitted and I would like them striped and then painted black enamel.

can you tell me how much do I dilute the acid. its 33% proof at the moment.

do I fully submerge the whole wheel, and how long do I leave it for

how do I neutralize the wheel after?

and other tips would be appreciated. I did have a disaster on my last acid attempt when submerging my shocks. it peeled the covering right off and ate it all away.

can you confirm that the chrome on motorbike wheels is nickel coated as stated in a previous post

many thanks

Darren O'Donoghue
hobbyist - United Kingdom

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Hi, Darren. Decorative nickel chromium plating would have nickel plating under the chrome plating, and this would certainly be the common bright finish, but it is possible to chrome plate directly on steel so nobody can confirm, site unseen, that there is no chance that the chrome was plated directly on the steel.

Hydrochloric acid is a dangerous and toxic material, so no one is comfortable advising a person of unknown background, who probably hasn't had haz-mat training, how to use it. But certainly goggles and gloves are among the minimum requirements. Immersing the whole wheel in 10-15 percent hydrochloric acid for a minute, then rinsing with good swishing, then neutralizing by dipping in diluted sodium bicarbonate, then rinsing again, would be the basic procedure.

As experience has already proven to you, money may be saved by having professionals do this for you :-)

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
October 29, 2009