Easy way to electroplate a small length of chain?

February 12, 2022 7:51 PM

What do I need in order to safely, easily DIY electroplate a small bit of utility chain? An anode? Some kind of acid? Some kind of pre-made solution? I'm looking for a $25 system at most, not including battery (9v?) if indeed a battery is part of this.

This was a galvanized (I think) chain that I got at Home Depot or Lowe's. The links are maybe 1/3-1/2" long, of wire that's ~4-5 mm in diameter.

Over time it became very rusty -- it was exposed to a lot of moisture. It was very easy to remove the rust with a salt and vinegar solution, but as soon as the metal hits the air -- and I mean in five minutes - it rusts visibly. Yes, I tried rinsing it in cold water; yes, I tried drying it.

Currently I'm storing it in a jar of mineral oil. Even this isn't keeping it perfectly preserved, it seems.

I'm wondering if there's an easy/fun way to just transfer some tin or zinc onto it. I tried Googling, but everything I found seemed to involve some scary-sounding acid which (I'm looking at you, HCl) only comes in gallon sizes. Can this really be true? I thought I did something as a kid on the kitchen counter with my dad that only involved a quarter and a nine-volt battery.

If there's a non-electric method, that would be interesting, since I'm worried about the current/charge being communicated across 300 or so links.

The whole chain fits into ~ 8 fluid ounces of oil, so it's not huge.

There's not currently a plan for this chain, I just hate to throw it away.

-- OR --

Uses for totally rusted/rusting small chain are interesting too. But I'm not a fan of rust in general.

posted by amtho to Science & Nature (15 answers total)

If corrosion protection is your desired end result, you'd probably be far better off building a little melting furnace and using that to hot dip galvanize your chain. Anything designed to melt aluminium will melt zinc even more easily, and you could get both zinc and the zinc ammonium chloride needed for the fluxing step of hot dip galvanizing for free by taking apart dead heavy-duty (not alkaline) batteries.

But what would be way way easier is to use a non-metallic corrosion inhibitor. I'd start by giving it an hours-long soak in a commercial rust converter, then hanging it up to dry completely, then coating it thoroughly with used vegetable oil, then baking it in the oven for a couple of hours to put a seasoning layer on it.
posted by flabdablet at 8:45 PM on February 12, 2022

Response by poster: Hmmm... the idea of baking some oil or something onto it is attractive, but I worry that the chain afterward...wouldn't be. Or that it would be sticky.


I think I read about some kind of chemical spray that would coat the metal? Is that something anyone knows about?

i.e. - I'm open to rust-proofing the chain in whatever way is easiest and gives a usable, not-hideous, not-gooey result.

(As much fun as a little melting furnace sounds, I don't really have anywhere to keep it, and I can't put a lot of time into this either. A lot == more than 20-30 minutes.)
posted by amtho at 8:54 PM on February 12, 2022

Could you try Plastidip?
posted by music for skeletons at 9:48 PM on February 12, 2022

I think there is no way you are going to be able to home electroplate something like a chain in a way that makes it rust resistant.

Because where the links are touching each other the underlying metal will not get completely plated, and the plating, in my experience plating metal objects that were touching, will tend to bridge the gap and sort of glue the links together and then break and flake off the first time you move the chain.
posted by jamjam at 10:09 PM on February 12, 2022 [4 favorites]

Exactly that. If you're hot dipping you can work around that with stirring, because hot dipping causes some of the zinc to alloy with some of the steel, and the resulting alloy is tougher than zinc, so when the zinc solidifies and you break apart the bits that will inevitably be sticking the links together, it doesn't pull the plating off the base metal. Electroplating doesn't do the same thing.

I worry that the chain afterward...wouldn't be. Or that it would be sticky.

You could cut one link off it for Science and try it out on that before processing the whole chain.
posted by flabdablet at 10:33 PM on February 12, 2022

I used this on some of my iron c-clamps. It worked fine.
posted by Marky at 11:12 PM on February 12, 2022

That's a spray-on version of the rust converter I recommended using before the vegetable oil seasoning.
posted by flabdablet at 2:53 AM on February 13, 2022

I rather suspect its hopeless, that the rust has created divots and cracks on the surface that really cant be removed. And is the cost of a replacement chain much more than the cost of the spray can of rust treatment?

OTOH, I admire the spirit of science experiment that I detect in your write up.

There is a gunsmith on YouTube who restores neglected weapons among other things, and he boils all the steel parts in water for about an hour. This converts the rust into a different form. Doesn't completely stop future rust, though.
posted by SemiSalt at 5:21 AM on February 13, 2022

I have no experience with this, but how about something like Corroseal? It chemically converts rust into a black, stable substance that protects the underlying metal against further corrosion.
posted by alex1965 at 6:26 AM on February 13, 2022

The only other thing I think just maybe? Is like cast iron teapots and the like. Again it's a just the right amount of heat for the right amount of time for the just right different sort of rust already covering everything that's black and not the red water type of rust. That's just controlling things to form a different oxide of Iron (Fe) and Oxygen (O). But that's about as complicated as firing pottery or something.


I wonder if there's something like this Amazon.com: Nushine Silver Plating Solution 3.4 Oz - Permanently Plate Pure Silver onto Worn Silver, Brass, Copper and Bronze ONLY (Ecofriendly Formula) : Health & Household that would put something on iron/steel in that just clean and dip and stir around a bit.
posted by zengargoyle at 6:59 AM on February 13, 2022

Given your time and monetary budget, an option might be to brush on or dip in a rust converter, then spray with a rattle can of an encapsulating paint like rustoleum.
posted by Short End Of A Wishbone at 8:23 AM on February 13, 2022

I have electroplated, at home, with a 1960s-kid's Chemistry Set. Not difficult. I have also paid for auto parts to be professionally chrome-plated (which is a three-step electro-plate process: first nickel, then a layer of copper, and finally the chrome. Which is why you might see something referenced as triple-plate chrome.) But the zeroeth, prep step is sand-blasting the object so its surface is smooth and polished. Heed jamjam's comment (how would you separate the links?) and also try to imagine how each link of the chain could be polished. May be possible, if they're big enough.
posted by Rash at 10:09 AM on February 13, 2022

Permanently Plate Pure Silver onto Worn Silver, Brass, Copper and Bronze ONLY

If the OP's chain's really been galvanized (which just means it's fresh steel that's been dipped in molten zinc) then this won't work. But flabdablet's suggestion is restoring the original galvanizing.
posted by Rash at 10:17 AM on February 13, 2022

Response by poster: I'm delighted that maybe some of you find this interesting, so here's more info:

I'm 85% sure all the previous galvanizing is gone, and that's what's left is steel.

I've already removed all the rust -- it was shiny when removed from the vinegar/salt solution -- but rust will form again very quickly if needed. I can make it shiny again easily, as long as I can put it into something else while it's still a little wet -- the time it takes to dry it will introduce more rust; it's really fast.

I'm considering the Rust-Oleum idea, but I'm a) worried about getting coating on the parts of the links that are close to other links (I mean, it could be done, but so finicky), and b) worried about movement among the links chipping that coating off.

There are apparently other coatings for metal to protect them from rust, but I'm not seeing small enough quantities.
posted by amtho at 10:28 AM on February 13, 2022

Best answer: You can buy 'cold galvanising' spray packs at most hardware stores and, while it would be a bit fiddly with such small links, you could spray the chain with no real problem. The advantage of this is that it's a sacrificial coating rather than an encapsulation - if there are a few bits missed, it doesn't matter as the coating will still protect it in the same way hot-dip galvanising would. I've used this type of paint before, in both spray and brush form and they've always worked well.
posted by dg at 4:39 PM on February 13, 2022