Brush Plating Nickel

"THE" brush plating book:
Electrochemical Metallizing by Marv Rubinstein

on AbeBooks

or eBay or

Amazon

(affil links)

A. Hi Norman. Regarding the books you asked about: There is a terrific one, "Electrochemical Metallizing" ⇨
which is solely about brush plating. For others, please see our Books page.

Regarding the correspondence schools you asked about: Kushner Electroplating School runs an introductory plating course, as does AESF. For a course specifically on brush plating, please try contacting the suppliers of brush plating systems. They can also refer you to brush plating shops if that's your preference. For more plating shops, please see the Directory of Jobshops.

There are no secrets, but when readers spend decades fully learning their trade, they do have a problem condensing everything you need to know into a few paragraphs. My first hint is that plating doesn't start with plating, it starts with a spotlessly clean and chemically active surface. Plating isn't painting, it's a process where metal grows on metal, and a quick guideline is that most plating problems are the result of a surface that is not truly clean. After you think it's already as clean as can be, scrub it with a tampico brush and a water solution of powdered pumice while wearing rubber gloves. If the surface isn't "waterbreak-free" it's not clean enough for plating.

Luck & Regards,

A. Hi Norm,

Most professionals are gun shy about about helping out hobby platers because there frequently is zero indication of what level of experience they have. Re-read Ms White's original letter. She gave zero information in her request about what she had tried or even what she was doing. ALSO, notice that she did not share her newfound information with anyone else but complained in the follow up letter about others that did not share.

Brush plating is very simple, but is extremely operator sensitive, like possibly 10 times what tank plater operators are.

The best answer is to follow the instructions of the vendor that you bought the kit and chemicals from.

When I was plating, I would not work on guns because of the liability. There are lots of things that can go wrong. 0.008" is a lot to try to put on a lug and have it stay on forever. Consider having it professionally done.

Good luck with your efforts. Try it on a dummy part before you try it on the gun.

A. Whoever you bought the "brush plating kit" should be able to provide you the sequence of chemicals and power to use.

Problems: the metal actually absorbs a minute amount of oil that is very difficult to get out. Any trace of oil will reduce the adhesion of an already difficult job. I would soak it in a hot alkaline cleaner for about an hour and then rinse well.

You will need to have an appropriate mask for the "not to be plated area", this is typically tape. If this "spot" is elevated, you will need to build up layers of tape to get the surrounding area very nearly level with the spot to be plated. Now you need an area of conductive foil to act as a thief or robber or bleeder so that you do not have an extremely high current density area on the sharp edges. Typically, this is metal tape with the end bent over and taped to the parent metal so that it is conductive. Aluminum does not live thru the cleaning step very well, so think about copper or lead.

The real secret to brush plating is the setup. For critical jobs, you really need a separate handle and brush for each solution and for the + or- direction of the current if it is used both directions. A very rapid changeover is required.

Keeping the part wet at all times is 100% mandatory, even if it is only water.

Use a good strike to where you see solid color. Not too much though, as this is terribly internally stressed.

Always start your brush stroke -- off of the part and sweep on/off. Your brush will probably be much larger than your part so you can stay on for a long time if you have a flow thru system. If you have a dip system, I really doubt if you will succeed. One method that can help is to use a lab wash bottle (squeeze squirt bottle) and try to keep the pad wet from above.

You probably will want a hard nickel, but typical max would be around 0.005" on an easy part. There are some "high build" nickels on the market that are hard. Sulfamate will be too soft but builds much better. There are some hardened sulfamates.

I have trained people in brush plating, including some very difficult ID parts, and I would only give myself a 30% chance of pulling your part off on the first try.

It is doable, but it is one big challenge.

Pre-bake your part after the alkaline soak for 4 hours at 375 to 400 °F. Bake it after plate also.

A. Hi, Norman. That 'baking' instruction has to do with this: Hydrogen embrittlement relief is a crucial element of plating hardened steel. If it isn't done both before and after plating, the plating absolutely can cause a rifle to blow up! While you wouldn't be expected to know that, every plating shop should -- so I don't think you'd "have to play hell" to show their liability over something they should know but you wouldn't be expected to know.

Sorry for your troubles, but the main reason for your exasperation may be that plating isn't quite as straightforward as we'd all like.

Best of luck.

A. YOU CAN BUILD THE THICKNESS UP WITH AN ACID COPPER SOLUTION at 8 VOLTS THEN NICKEL PLATE ON TOP WITH THE NICKEL FOR HARDNESS EASY HONEST ...

Thanks, David. That sounds like good advice!

Regards,

A. The MFSA's Quality Metal Finishing Guide recommends a radius of at least 1/64" and preferably 1/32" for decorative copper-nickel-chrome plating; but it doesn't address brush plating. But I don't think the nickel should chip or peel regardless.

Just wanted to say thanks to Ted Mooney for the quick response.

Thank you,

A. Hello Mark,

Ted mooney is correct. There should be no chipping or peeling from the edge of a brush plated deposit. There are procedures that will enable brush plated deposits to be built well over .005" with no chipping on an edge.

A. James Watts and David Park offered excellent practical advice to Norman, and I suggested the books, training courses, and plating shops that he asked for.

A beginner, Norman, first time out, asked how to do nickel plating that is 3 times as thick as most experienced professionals will even attempt; Mr. Watts spent a great deal of time with him on two occasions both explaining this and offering specific answers -- but Norman still seemed to insist that Mr. Watts was wrong, that plating of that thickness shouldn't be difficult, and that people were only claiming it was so they could "charge through the nose". Considering the circumstances, it was not pedantic to make it clear that -- sorry -- plating 3X thicker than professionals can do is hard.

I've spent 40 years in plating and still learn a lot every day, and am not ashamed that I can't quickly tell a beginner how to do a plating job that most professionals won't attempt. But besides my advice on proper cleaning, the second piece of advice I'd offer is that you have to practice on scrap, and not once or twice but 10, 20, 50 times if necessary, until you get the hang of it.

!! DON'T PLATE THE LUGS ON YOUR RIFLE, THIS WILL BLOW YOUR HEAD SPACE AND MAKE YOUR GUN INTO A GRENADE! IF YOU PLATE THE LUGS YOU MAY NOT BE ABLE TO COMPLETELY CLOSE YOUR BOLT WHICH WILL OBDURATE THE CASE HEAD SUPPORT AND POSSIBLY RIP THE LUGS OFF BOLT, SENDING THE BOLT CRASHING INTO YOUR FACE. AND IT DOESN'T TAKE A SCIENTIST TO KNOW YOUR FACE IS SOFTER THEN THE METAL THAT WILL BE FLYING AT YOU. GOOD LUCK WITH THAT THOUGH.

A. There is a good article in (AMERICAN GUNSMITH) NOV. 1992, titled "Electroplating Small Parts".

Brush-plating small parts is easier than you think. It just takes practice and a little patience.

A. Hi, Robert. If you are now lacking any documentation maybe you could try to find a copy of Rubinstein's "Electrochemical Metallizing", which is the bible for brush plating.

Regards,

A. Ted's advise is the way to go, but in the mean time I will try to answer your questions.
1- You are supposed to use long fiber cotton and pull it to wrap it tight around the anode. If you cut it in short pieces, it tends to loose and move or un-wrap during processing (anode sleeves are not enough to keep it tight)
2- The color of the cables is theoretically irrelevant. As long as you connect the brush to the positive terminal on the power pack and the part to the negative for plating (FORWARD). Of course, etching and some cleaning steps on some metals require REVERSE polarity. Then the brush is negative and the part positive. If you make a mistake you may ruin the part. For instance if you use forward polarity when cleaning a high strength steel you may induce hydrogen embrittlement in the part. If you use reverse with an acid solution you may dissolve metal from its surface instead of plating it or building it up.
3- The best vendors advertise here. Just take a look.

A. Hello,

I am Bob Brookshire's last stepson and a former employee of Brushtronics Engineering.

From my memory Guillermo Marrufo's answers #1 and #2 are correct.

Found this thread through a random Google search. Hope Guillermo's answers are helpful.

JW

Great to hear from you, Jesse!

Luck & Regards,

A. Hi Michael. I think you've heard right. The nickel serves two purposes: brightness, and preventing diffusion between copper and gold. So if you're not nickel plating, you do need to get the copper quite bright and reflective before doing the gold plating.

Luck & Regards,