Difference Between Chrome and Nickel Plating

A. Hi Edward. Sorry, no it cannot. Please tell us the full situation and the response can probably be fleshed out in a helpful direction.

Luck & Regards,

A. Hi Edward. Sorry to say, you're reading correctly. Very small scratches might be filled, but pits and large scratches will be worse after the plating rather than better. Small pits and scratches can sometimes be heavily copper plated and then "mush buffed" to mush copper into them, before nickel plating but larger pits can require solder, brazing, or welding that are a practiced skill.

If any of these components are pitted zinc die-castings you have a long road in front of you :-(

Luck & Regards,

A. Hi Tiziano.

Conventional electrolytic nickel plating is decorative, functional, and somewhat corrosion resistant but it tarnishes and it is not as hard as chromium.

Electroless nickel plating (actually autocatalytic nickel plating) is a glassy nickel-phosphorous coating that is very corrosion resistant and quite hard, and often used on rough-service applications like down-hole applications.

Chrome plating may be either a thick layer of chrome (generally known as hard chrome) that offers exceptional hardness, wear-resistance, and oil-holding capability, but limited corrosion resistance; or it may be nickel-chrome (nickel plating followed by a flash of chrome for tarnish resistance and extra corrosion resistance, as is employed on truck bumpers and automotive brightwork).

For interior stuff, where the elements are not too rough on it, the choice between nickel plating vs. nickel & chrome plating can probably be based on the look of it. Nickel is very slightly yellowish and chrome is very slightly bluish, so nickel is warmer looking and chrome is bling-y-er.

A. No, that is not totally correct, Jirapan. It is very unlikely that the lamp was only chromium plated; it was almost surely nickel-chromium plated; that is, it was nickel plated then chrome plated, with the chrome being only a few millionths of an inch thick. So if something peeled, it was the nickel plating.

But if the job is done right the plating will not peel. You are correct that nickel plating which is not later chrome plated has a slight yellowish tinge which grows more pronounced with time as the nickel tarnishes. Good luck.

Thank you so much for your help, Ted.

A. Hi, Srinivas. Although anything can be done well or poorly, nickel-chrome plating is a special case that must be done really really well; anything even slightly short of that is really really bad (see our "Understanding Chrome Plating"). When done poorly not only does the plating contribute nothing to corrosion resistance, it greatly accelerates corrosion because nickel is anodic to the underlying steel and turns the underlying steel into a rapidly corroding sacrificial anode.

But "defective" is probably not quite the correct word, because the item may well have met the plating specification they wrote for it. "Crappy" would probably be a good word for it :-)

Regards,

A. Hi, Trev. Nickel and Nickel-Chrome plating are rather similar in appearance, with the nickel plating being slightly yellowish due to its tarnish, and the chrome being slightly blue-ish. Either on a railing would probably be "close enough" to match a brushed chrome door handle; but if it's for exterior use, the chrome would be a very good idea.

Regards,

A. Hi, Kristen.

You won't find anything made of solid chrome -- and chrome plated jewelry would be very unusual. What you may find that is nickel-free though is rhodium plated or silver plated jewelry. I believe that all jewelry sold in the European Union is supposed to be free of leachable nickel.

Yes, there is such a thing as chrome plating without an underlayer of nickel -- it's called hard chrome plating. But it is used as a wear resistant engineering finish for things like piston rings, not as a decorative finish. Good luck.

Regards,

A. Hi cousin Fernan. All metals can be plated with either or both.

Nickel plating is usually not suitable for outdoor exposure because it tarnishes too quickly and severely. Nickel-chrome plating is brighter and more suitable for outdoor use. Hard chrome plating is not a decorative finish, and not especially corrosion resistant, but is a functional coating for wear resistance and oil holding. Any of the three can be applied to almost any substrate, but again, what are you trying to achieve? For example, you can theoretically do hard chrome plating on aluminum, but it's probably not useful since the chrome plating will crack like an eggshell if you put a heavy load on it.

Experts will probably be happy to try to help you determine what is better for a carefully detailed situation, but trying to impart enough information that readers can write a plating specification themselves may not be possible. Most plating consultants acquire at least 25 to 30 years of broad plating experience before they do it :-)

Good luck and please get back to us with a specific case!

Regards,

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A. Hi Michael. Chrome is not actually clear, it is bright metallic and very slightly blue compared to silver or nickel. But it is very very thin, such that it is the underlying nickel that gives the smoothness necessary for high reflectivity. And yes, it helps keeps the nickel plating from tarnishing.

It is theoretically possible to chrome plate on top of old nickel, but for good adhesion you normally need a pretty aggressive "activation" step or sequence to activate even relatively fresh nickel, let alone decades-old nickel.

It is not going to be useful and probably not possible to do a spot repair on a nickel-chrome plated piece. The chrome will be extremely passive and nothing will adhere to it. It is also important to remember that nickel chrome plating offers "barrier layer" protection to steel, not "cathodic protection".

If you picture how ships use zinc anodes to corrode away to protect their steel hulls, nickel-chrome plated objects inadvertently use pits in the steel to galvanically protect the nickel chrome plating. Any porosity at all means the tiny spot of exposed steel will be a tiny volcano of rust corroding away trying to galvanically protect the plating. Poor nickel chrome plating greatly accelerates rusting. Try to remove the rust with chrome polish and ultrafine steel wool, then keep the area waxed (or clear coat it), or try a chrome-look paint.
Good luck.

Regards,

A. Hi Jeff. Your only serious choice for high decoration is nickel-chrome plating. Nickel plating alone won't hold up in a corrosive outdoor environment. However, as a cost reduction measure, rims and brackets are sometimes acid zinc plated and clear coated. It's not nearly as bright as nickel-chrome plating, but can be cheaper and more practical.

If cost isn't an object, nickel plus black chrome plating can be very nice. But nickel-chrome plating is expensive and most shops charge significantly more again for black chrome.

Regards,

A. Hi Manuel. It's not that the chromium metal itself is not corrosion resistant, it's that the plating won't prevent the underlying steel from corroding. Chrome plating is almost always cracked. Sometimes very deliberately "micro cracked" or "micro porous" as part of the plating process. So, when chrome plating is applied directly to steel in the hard chrome plating process, the component will have rather limited corrosion resistance.

Regards,

A. Hi Jay. One possibility is a layer of nickel plating or electroless nickel plating under the hard chrome plating to improve the corrosion resistance.

Electroless nickel by itself has some of the properties of hard chrome plating, while being more corrosion resistant; the "holy grail" would be electroless nickel plating in lieu of hard chrome plating ... but it's not easy. A literature search will probably show a dozen papers just on the one subject of electroless nickel plating of hydraulic cylinder rods and why it doesn't quite work. Good luck!

Regards,

Hi Devang. The electropolishing option applies only if you make the basket out of stainless steel. If you do that, it's probably the best option as it will likely have more durability. You can't usefully electropolish plain steel, and even if you can it has no rust resistance.

Regards,

A. Hi Curtis. Plating chrome on top of nickel is a commonplace. In fact, when people talk about decorative chrome plating, they mean a heavy plating of nickel followed by a thin plating of chrome.

It probably isn't impossible to plate nickel over chrome, but "it isn't done" to my knowledge. Good luck

Regards,

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A. Hi Christian. I presume you are interested in a small and manually intensive system, but to my knowledge there is no such thing as a chrome plating machine in the context you are thinking of. What there is, is a custom designed chrome plating factory with a proper floor, proper selection of a dozen or so plating tanks for cleaning & plating & post treating, heating systems, exhaust ventilation and fume scrubbing systems, filtration systems, waste water treatment equipment, power supply rectifiers, buffing equipment, wet and dry laboratories, etc. Your first step if you can work it should be to visit a couple of chrome plating shops.

Realistically I'm afraid you have two choices: retain a plating consultant to work with you to design or design/build a plant that can handle the mix of work you envision, or buy nothing and commit yourself to intense study for the next 6 months or more before considering your next move. Best of luck!

Regards,

A. Hi Ashok. As implied in the above discussions, nickel-chrome plating combines some advantages of nickel plating with some advantages of chrome plating. The nickel plating provides the leveling and shine and much of the corrosion resistance. The thin micro-cracked layer of chrome adds hardness, reduces tarnishing of the nickel, gives it more brightness and bling, and distributes the corrosive energy to symbiotically reduce corrosion.

Most nickel-chrome plating processes will have an HCl activation dip just before the nickel plating to remove any oxide from the surface. But it is difficult for us to start with rough details of what you think you saw and extrapolate to the fine details of what you might have seen. It is not usual to have H2SO4 before the HCl but it is possible for the plating process to incorporate a Madsenell Etch or an Acid Cleaning step. More typical would be alkaline cleaning, followed by HCl, followed by plating (with rinses in between each step). Good luck.

Regards,

A. Hi Dave. Nickel-chrome plating is not "automatically" a corrosion-resistant finish --

If done very well it is highly corrosion resistant -- truck bumpers and Harleys can last decades. But if done poorly it is the world's absolute worst finish because nickel is cathodic to the steel, so if any steel is exposed due to porosity or pinholes, the steel will be powerfully driven to be a sacrificial anode and rust away rapidly. Please see the previously mentioned "Understanding Chrome Plating" for further explanation and for photos of lousy nickel-chrome plating.

"Salty conditions" is a possibility, but more likely these days is that the hinges are simply crap from China with zero effort towards proper finishing. The referenced article shows has pictures of bathroom accessories rusting in a big-box store before the consumers even purchase them. Remember the brand name, and where you bought them, and do your best to not patronize them again :-)

Regards,

A. Hi Michael. Although it is not possible to do chrome plating by brush plating to my knowledge, there are chrome plating substitutes that can be brush plated and may be "close enough". In that case you would do the nickel plating first and then top it off with a thin layer of the chrome substitute.

"Bright nickel" is fairly bright, but it is still "yellowish" compared to chrome plating, and it will tarnish. Our FAQ explains that bright nickel is often part of a two-layer nickel plating system where the inner layer of semi-bright nickel is "cathodic" to the bright nickel so the corrosive forces are spread laterally through the bright nickel layer rather than penetrating the inner layer and allowing steel to become exposed.

The bullion is not a proper material for nickel anodes; you'll want sulfur depolarized nickel anode material.

Plating is not like painting; significant knowledge, experience, and skill are required; hazardous materials are used, and hazardous wastes are generated. It's not impossible to do electroplating yourself, but 99% of individuals will find it highly impractical to brush plate wheels. Chrome plating shops are not opening in droves, they have been closing in droves -- so while "£200.00 plus" may seem like a lot of money, it's apparently not enough for them to prosper :-)

Regards,

Hi, thanks for the reply, like you say maybe the best option would be to let the guys do it. I work as an auto electrician and started off as a bench fitter years ago rebuilding starter motors and alternators, we used to prep carcasses for zinc plating so explained this to them; I have all the available machinery to prep and they will coat for £200 there must be a huge amount of overhead. Again thanks for your reply.

A. Hi Dr. Hewamadduma. I don't think the temperature will be a limitation for nickel-chrome plating. But plating does not fix pits and scratches and it can be difficult to get the aluminum scratch-free and pit-free before plating. Maybe you can strip the paint, see what you've got, and whether it look plateable. Good luck.

Regards,

A. Hi David. Bumpers aren't just nickel plated nor just chrome plated -- they are nickel plated then chrome plated. There is probably no reason the finish can't be "brushed" before/during plating if that's what you want, but glass bead blasting before plating is probably the easiest path to a matte finish. Good luck.

Regards,

Hi Rajesh. Please start with our "Understanding Chrome Plating", then get back to us with specific questions. Good luck.

Regards,