Chrome plating removal from Aluminum Wheels

A. Doing a good job of chrome plating alloy wheels is hard, and it is common to buy rims from which the chrome peels. But if the supplier feels that it is too difficult to plate wheel rims reliably he should get out of that business. As a plating industry professional I'm tired of consumers encountering this problem. The chrome is not supposed to peel. Period! Demand your money back!

If they are too old to return, and you want to strip and polish, I would not suggest sandblasting because the aluminum is much softer than the material you are trying to blast off, so you'll probably end up with a spongey pockmarked surface and a poor start towards polishing.

I think you're on the right track wanting to send them to a plating shop for chemical stripping. The plating is actually multiple layers, probably electroless nickel plating, followed by copper plating, followed by nickel plating, followed by a very thin plating of chrome. Although the chrome per se can be readily stripped in muriatic acid, the nickel plating, and especially the electroless nickel plating are hard to remove even with aggressive and toxic chemicals. Good luck.

A. Mark, Gary_: The chrome per se is removable relatively quickly with muriatic acid [affil links]. But, such wheels are actually nickel plated and then chrome plated, and most of what you are looking at is actually nickel.

It may be possible to sandblast them, but sandblasting is not good for aluminum and you'll never get it smooth again. Chemically stripping the nickel requires proprietary or toxic chemicals that aren't easily available to or usable by consumers.

I think your best bet is to take the wheels to a plating shop or powder coating shop for stripping the nickel and applying a chromate conversion coating before painting or powder coating. Best of luck.

A. Hi Peter. Various things can cause discoloration, pitting, and other problems -- but peeling is always a manufacturing defect. Getting proper plating adhesion onto pressure cast aluminum wheels is very difficult, but if they can't do it they shouldn't offer it. Sorry to hear that the wheels were expensive and only lasted two years.

Luck & Regards,


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

A. Normally you would use muriatic acid [affil links], probably between full strength and half strength to strip the chrome per se.

It should be used in polyethylene, polypropylene, or vinyl containers. Remember that acids can burn, blind, or poison you; so use with good ventilation and appropriate personal protective gear; and re-read your high school chemistry text if you find no warnings on the bottle. Also, muriatic acid releases fumes, and you'll read many horror stories on these pages of the effect of those fumes on stainless appliances in the house, etc.

To an extent, the acid can be reused. However, its power is consumed by the work you ask it to do, so it gradually weakens; and HCl is volatile and will slowly escape an open-top tank over weeks or months.

When you're done, the chrome will be off, but the nickel (and possibly copper) will still be there and you'll only be up to step two of several. Next you'd have to go to concentrated nitric acid or cyanide or a proprietary stripper to remove the nickel. You can contact Metalx (Ronatec.us) [a finishing.com supporting advertiser] about getting a nickel stripper, but I think it would be worthwhile to take them to a plating shop for stripping, rather than getting involved with this. Good luck.

A. Hi, Corey. Hi, Edwin. Hi, Steven.
The question has already been answered on this thread. When answers aren't "solid", it's often because the questions are a bit vague :-)

First, real magnesium wheels are very very different from aluminum alloy wheels, yet people ask what to do about 'mag wheels', leaving us wondering which they mean; and pressure cast aluminum alloy wheels are quite different from rims machined from billet aluminum -- which of the three do you have? Answers also depend on what you want to do with the wheels after removing the chrome. Do you want to prepare them for re-plating, or leave the nickel plating on them for a warmer more classic look than chrome? Or are you trying to prepare the wheels for powder coating? Or trying to mirror polish billet wheels and leave them as polished aluminum?

Some people feel that sandblasting is best, but it leaves the aluminum very rough; some think that chemical stripping is better but it may depend on how much training you've had with toxic chemicals, what kind of personal protective equipment you already have, and whether you already have a sandblast cabinet. Asking for "the right way" can be like asking whether a Porsche or a Kenworth is the right vehicle to buy without giving us any other info :-)

Powder coaters have told me of their success with a light sandblast that removes the chrome and lightly etches the nickel. And it's a fine answer if you want to powder coat them, but not if heavy layers of nickel are peeling, nor if you intend to polish them or re-plate them. In those cases you must chemically remove the nickel and you can't easily do that yourself; you might want to take them to a plating shop because you can't dissolve nickel into chemicals commonly available to consumers, but try contacting Metalx (Ronatec.us) [a finishing.com supporting advertiser] for proprietary nickel strippers. Oven cleaner is useful for removing anodizing but not nickel plating -- it'll dissolve the wheels while not dissolving the plating! Sorry. And best of luck with it.

Regards,

A. Hi, Jason. Although I don't claim great artistic taste, that sounds to me like an interesting look. Too bad the manufacturer doesn't offer the wheels with the smaller spokes primed to facilitate what you want to do. Make the suggestion and maybe they'll do it for you as a test market :-)

The ideal prep is to get the aluminum alloy all the way down to base metal, then chromate conversion coat it and paint it -- but that may be difficult even for a metal finishing shop. So I'd say the practical approach is to lightly blast to remove the chrome and etch the nickel; I can't guarantee the level of adhesion, I can only repeat that some powder coating shops claim good success. Best of luck.

Regards,

Thanks for the quick response Ted. I appreciate the help.

A. Hi Jared. The very thin top layer of chrome can be removed by a dip in muriatic acid, but the only 'generic' chemicals that will dissolve nickel are a cyanide stripping solution or concentrated nitric acid, neither of which is at all practical. So I suggest that you call Metalx (Ronatec.us) [a finishing.com supporting advertiser] and see what they say; they have a much less toxic proprietary nickel stripper, and they may either know a stripping shop closer to you, or they may be able to sell you their product and advise you how to do it yourself. Good luck.

Regards,

A. I work at a tire shop I see this stuff daily ...p eople with this issue with newer rims just simply don't take care of them properly, most have never heard of a car wash. I have rims that are 10 yrs old that aren't peeled or blistered, but I wash them weekly in winter and not with an automatic car wash as they don't direct enough water to the wheel. Instead, don't be lazy; find a self service car wash or buy a pressure washer and hose them off.

A. Thanks Jeff. It's certainly good advice to wash away corrosives regularly, as they can dull the chrome wheels, or pit and corrode them. But count yourself lucky because peeling is a manufacturing defect having nothing to do with storage or use conditions.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 21, 2013

A. Perhaps but peeling doesn't happen if properly taken care of

A. Sorry Jeff, but that's simply not true. If you have a laminate which is missing glue in spots, it will come apart no matter how you baby it. And when the multiple plating layers (zincate, electroless nickel, copper, semi-bright nickel, bright nickel, chrome) are not properly activated, you have spotty "glue" holding them together instead of a continuous sheet of good adhesion.

The fact that your wheels are kept clean and don't peel doesn't mean that other wheels that are kept clean won't peel, nor that letting wheels get dirty will cause them to peel.

Again, keeping things clean is great and can prevent rust, corrosion, pitting, and other problems . . . it is very important! But it has no effect whatsoever on peeling. I don't enjoy being argumentative, but I have to because we can't let manufacturers ship defective products and get away with blaming it on the consumer. Peeling is a manufacturing defect, period. If you're still not convinced please see thread 48729 where 6 professional platers say exactly the same thing.

Regards,

Ted Mooney, P.E.
Striving to live Aloha
finishing.com - Pine Beach, New Jersey
April 23, 2013

A. Hi Orlando. There used to be a couple of hundred plating shops in NJ, but after decades of harassment from NJ DEP there are only a handful left, and I highly doubt that any of them can/will do this chrome plating for you. Usually custom lead fixturing is required for chrome plating such wheels (to make the electricity go where you need it to go). And they probably don't have it on hand for such a rare job, and can't afford to build it for plating one wheel. A replacement wheel plated somewhere else is probably much cheaper than re-plating the one you have. Sorry.

Regards,

A. Hi Aaron. Real nickel and chrome are never plated onto painted or powder coated wheels. That tells me almost for sure that what you are describing is not real nickel-chrome plating, but "chrome-look paint" or PVD coating. This is a 3-layer system of: a smoothing base coat; a layer of aluminum flakes or reduced silver for the shine; and a clear top coat.

So you are trying to remove paint from paint/powder, and the hard part will be to try to dissolve the one layer without hurting the other (I don't know whether it will even prove possible). But the general approach is that you should be looking at paint strippers rather than blasting or the chemical strippers you would use for removing nickel plating.

Although I suppose it's possible that the paint under the shiny layer is robust, I wouldn't count on it because it wasn't intended to be good against abrasion and UV. Good luck.

Regards,

Ted, thank you for sharing your knowledge as a coatings specialist, Best solution was taking rims to plating shop and have them remove the chrome; its well worth it to do it the right way instead of half ass'ed

A. Hi Adam. Before about 1930 there was only nickel plating on car parts. If you get to Virginia you can see Woodrow Wilson's 1919 Pierce Arrow with its beautiful nickel plating at the museum in Staunton. But unless you are willing to polish every day or two, or clearcoat it, you probably won't be happy with nickel plating.

Regards,

A. Hi Deron. The powder coating can be removed with aircraft stripper, or hopefully something less toxic and more environmentally friendly. The chrome plating per se can be removed with muriatic acid. The nickel plating, which is always below the chrome, can be removed with various strippers. But finding a shop who can do it, let alone at an affordable price, may not be easy; and you don't want to mess with a whole bunch of very toxic chemicals yourself that you're not trained in. Blasting is probably a poor idea because the plating is much harder than the underlying aluminum. Good luck.

Regards,

A. I have tried grinding off the chrome and this works to a certain extent along with a Stanley knife to peel off the bigger sections which are not well attached. Extremely time consuming and easy to scratch or indent the aluminium alloy. Taken very carefully this is possible.
However, I am handing in some alloy motorcycle parts to be stripped of the chrome /copper/nickel plating tomorrow. I'll get back to you when this is done to see how the job affects the aluminium alloy

A. Hi Paul. There is no way the plating is adding anything like 30 lbs. The plating is unlikely to be much more than 0.001" thick, tops. If the surface area plated were, say, 7 sq. ft. per wheel (and I doubt it's more), that would be roughly a cubic inch of metal, for a weight of about 0.3 pounds per wheel.

But you can contact Metalx (Ronatec.us) [a finishing.com supporting advertiser] and see if they can sell you nickel stripper, along with instructions for its use.

One thing to be careful of, of course, is that people (possibly including the wheel vendor) sometimes toss around the word 'chrome', using it describe any shiny finish. There are a lot of 'chrome wheels' out there that are not nickel-chrome electroplating, but 'chrome-look paint' or PVD metallized, etc.

Regards,

Q. Ted, I think you misunderstood my reason for a 30 lb difference. I bought a new set of aftermarket rims but they are not Aluminum Alloy they are polished/painted steel because buying Alloy for the odd wheel dimensions on the 2009 CTS V led to very few choices and prices starting at the 6k range. Even with steel rims the choices are few. I want to redo my original Alum. Alloy rims because of the weight differential between Alum. & Steel. That's why the 4 wheels added up to a 30lb. difference. The stock factory alloy's are almost 7k. So,refinishing them and using only as summer wheels is worth it if I am able to properly do it. Plus the performance difference is a benefit. Anyway, thanks for your info.

A. Okay, understood. It's hard to know exactly what the finish on your wheels consists of, and therefore how to remove it. And there is also the question of whether the underlying aluminum alloy will polish well, but I think Metalx (Ronatec.us) [a finishing.com supporting advertiser] is your best hope for chemically removing the nickel plating and the possible electroless nickel underlying that. Some high quality alloy wheels are done with the following process: zincate, electroless nickel, copper plating, nickel plating (possibly multiple layers), chrome plating. The chrome is easily removed with muriatic acid, but the nickel and electroless nickel are tough. (And Metalx might even know an East Coast shop which will strip them for you).

Regards,

A. Hi Kim. The chrome will come off in minutes, probably less than a minute. What I would consider doing if I were you would be to send the wheels out for fixing. The plating shop can probably carefully mask the good chrome on the center, then chemically strip the chrome and the nickel and the copper (if any) and the electroless nickel (if any), chromate the aluminum, powder coat the wheels, and remove the masking protecting the chrome in the center.

If you want to do it yourself, this as least gives a guide to the plating layers you may see. Plating on aluminum starts with an immersion deposit of zincate which does not offer as much adhesion as electroplating, so I think you are right that a thin and flexing section of an aluminum wheel is likely to lead to non-adherent and unsatisfactory plating.

Regards,

  Thank you; I did not think masking would be an option .