Is there a good way to remove nickel plating from brass valve stem covers?
Best: Use a nickel stripper for copper base metals. Available at Caswell's.
Cheap: Buff the nickel off. Use white rouge and a buffing wheel.
Soak in Muriatic acid for a short period (One hour or two) and it will peel right off. Buff and you have shiny brass. Done it many times.
Acid is available at any masonry shop and also at Home Depot
Paint them with a coat of varnish and no one will ever know.
Hydrochloric/Muriatic acid (HCL) will dissolve nickel if given enough time. Proof of this would be the solution turning a blue-green color. You can also add about 10% hydrogen peroxide to accelerate dissolution. The problem is that HCL will vigorously attack brass and strip the zinc out leaving a very porous surface of copper. It takes a lot of polishing to get down to a fresh layer of brass.
I suspect Jon's experience with the nickel "peeling off" is the result of the brass under it being dissolved, not the nickel. I would not use this method on thin brass or brass sheet items like the valve stem covers.
Forgot to mention: You will also loose a lot of detail caused by having to get down to "new brass" using the acid method.
I've heard that a plating shop will do it for you, and possibly free as they will recover the nickle. I believe they can do it in about 5 minutes electrically. I have not actually had it done but my understanding is that this is the first step in bumper repairs ( removing the old plating and they recover the chrome and nickle)
I've used both the stripper and the electrical methods and neither is a 5 minute job for nickel. The stripper takes about a hour+ and reverse plating takes almost that long. (Unless you're not saving the nickel and burning the anodes.)
Chrome can be stripped in about 10 seconds. Nickel takes much longer because it's thicker--About 1000 times thicker.
What's good about the nickel stripper is that it does not attack the base metal. I used it exclusively back when I was doing plating.
Where is Caswell's? Will the nickel stripper be ok to use on a brass radiator that was nickel plated?
Mike: http://www.caswellplating.com/electroplating-anodizing/metal-strippers/metalx-b- 929-nickel-stripper-2-5lb.html
The nickel plating on a typical dust cover is very thin so it shouldn't take long with muriatic acid aka hydrochloric acid. Maybe twenty minutes or less - not an hour or two.
You can also buy a bottle of "The Works" toilet bowl cleaner at the Dollar Store, Walmart, Target, etc. It is 20% hydrochloric acid.
Roger beat me to it. (Thanks for looking it up.)
Mike - Yes but it will take a lot (volume) to immerse the entire radiator. Not to mention costly. And the solution needs to be heated and agitated. Probably better to turn that over to plater with large tanks.
"Very thin" has no meaning in plating. Typical bright nickel plating for items exposed to handling or the environment should be .00075-.001" thick. That is "THICK" in plating terms. Something like chrome plate is only a few atoms thick. I still disagree with using any acid on brass. The zinc will dissolve in seconds and you're left with a layer of red copper. It just makes for more work. But it's your choice.
I know there have been endless comments on this in many other threads, but is Muriatic Acid a good way to get brass to shine without have to deal with removing residual Brasso from cracks and crevices?
Bottom line.....nickle plating is correct for all valve stem covers. They were never finished in brass. Just FYI.
Ed aka #4
Glass bead removes the nickel easily. Then sand with 1000, 1500 and 2000 grit. Polish the brass with a sewn sisal wheel and some green rouge. Finish with Prism polish.
Royce The bead blasting worked very well.
The later nickel plated valve covers turn down nicely on the metal valve stems that come on the currently available inner tubes. So if you can remove the nickel plating off the brass, you can get valve stem covers that look more like the correct ones for a brass car, and for a skin-flint price. Too bad you have to thread them on so far though.