A few months ago, I was working on a leather project and needed just the right belt buckle set to go with the piece. I found the perfect one, except that it was only offered in brass. The rest of the hardware was silver/chrome, so I needed to fix that. My first thought was to spray paint the buckle, but quickly realized that would give a cheap-looking appearance and flake off quickly. Choosing instead to electroplate the piece, I began research. There are tutorials and videos here and there online, and I tried a few with unacceptable results.
Kits online are expensive, and I wasn’t going to pay hundreds of dollars for a one-off project. I reached out to some experts in the industry and found nickel plating methods are actually a rather closely guarded secret. The folks I spoke with gave only vague direction. Well, hoarding knowledge to oneself doesn’t sit well with me. Obviously it was time to do some experimenting. In the process, I accidentally discovered a method that worked very well, and then further developed it.
I’ll spare you the discovery process and notes until the end, and jump right into the method. Here’s what you need:
- 1 x 6 volt lantern battery
- 1 x source of pure nickel (Nickel anode from Amazon, nickel guitar strings, nickel welding rods)
- 2 x ~12 inch wires
- 4 x small alligator clips
- 1 x piece of thin cloth or paper towel to cover anode
- 1 x disposable plastic/glass container (tall Rubbermaid containers are great)
- Boric acid [30-45 g/l of electrolyte] (Hardware stores carry for pest control)
- Nickel sulfate [225-400 g/l of electrolyte] (Most expensive item, I got mine here. A 500 g bottle is more than enough for a handful of experiments)
- Cooking thermometer
- Disposable, powder-free gloves
- Roll of paper towels
- Chopstick or similar
- Masking tape or similar
- Simple Green or other degreaser
- Cameo or other acid-based metal cleaner
- Scrub pads/old toothbrush
- Sandpaper, 600-1500 grit (or higher)
- Metal polishing compound or choice of finish
Prep the object to be plated. Brass plates well, copper is a good choice. I haven’t done much testing on various metals so you’ll have to give it a try. The name of the game with prep is clean. The metal must be absolutely free of dirt, grease, oxidation, or any other barrier between the bare metal and the nickel to be deposited. After donning gloves, scrub the piece with a toothbrush or pad and full strength Simple Green. Rinse it under hot tap water. Then make a paste with Cameo and a tiny bit of water, and scrub again. Give it a final, thorough rinse under very hot water and place on a clean surface (clean paper towel).
Mix up your electrolyte solution by combining tap water with nickel sulfate and boric acid per the above quantities. I went with 40 grams boric acid and 300 grams nickel sulfate in a liter of water.
The electrolyte solution must be in the right temperature range: 100-160F. I just put it in the microwave a couple of minutes, stir it, and take the temperature. It’s best to start out on the higher end of that range of course, to give you more working time between reheating.
Wrap the nickel anode in a piece of thin cloth and immerse it in the warmed solution, leaving a bit of bare metal exposed above. Tape it to the side of the container. Attach an alligator clip to both ends of each wire. Attach one clip to the nickel anode and the other end to the positive terminal of the lantern battery. Attach one clip from the other wire to the negative terminal of the battery. Wearing gloves, pick up the piece to be plated and connect the last clip to it.
Immerse the piece in the electrolyte solution for ten or twenty seconds. Remove it, and inspect the piece for nickel deposition. Typically, areas will begin to emerge that refuse to accept plating, while other spots plate well.
After just a couple rounds of immersing and inspecting, these spots should be obvious. Now, unclip the piece and sand the spots that won’t take nickel. Begin at about 600 grit and work up to your desired polish. I was happy with 1500. Make sure to sand the transition between plated and bare areas to avoid imperfections. Once you’re satisfied with the sanding, repeat cleaning the piece with Simple Green and Cameo. Make sure your electrolyte solution is at the proper temperature, clip the piece again, and immerse.
Repeat this process of immersing, looking for bare spots, sanding, cleaning, reheating, and re-immersing until the nickel is depositing the entire surface of the piece. It is as painstaking as it sounds, but that’s the trade-off for getting good results without spending hundreds on a pre-made kit or service.
Once the entire surface of the piece is accepting nickel, reheat your electrolyte solution to near 160F. Tie a loose overhand knot in the negative wire, closer to the end holding the piece. Put the chopstick through the knot, and use it to suspend the piece in the solution without touching the container walls.
Allow the piece to plate for 10-20 minutes, rotating every three minutes or so. It’s suggested you gently agitate the solution with a plastic spoon or knife during this process, as seen in the photo above.
Once the piece is fully plated, use super high grit sandpaper, polishing rouge, or other method to finish the nickel surface.
I originally followed directions from an Instructable that had me trying to make electrolyte by electro-dissolving nickel in a solution of salt and vinegar. The plating bath turned the blue-green that told me I was on the right track, but I left it to bubble until an entire anode was dissolved in the solution, and I still couldn’t get decent results. Of note- the tutorial I followed made no mention of warming the electrolyte, which several other sources suggested, and my experience confirmed, is vital.
I did more research after that first long and miserable failure, and found the right compounds and proportions for a proper nickel plating solution, as mentioned above. Once I ordered the right stuff and mixed up the solution, it was obviously much more saturated than the Instructables version.
I actually kind of accidentally discovered the sanding method. I used the same brass loop pictured above to continue refining my recipe. The first try was gritty and terrible. Since I didn’t have much spare brass to practice with, I just sanded it back down and tried again. As I went on, I noticed that not only was the quality of the nickel plate improving, but coverage was increasing as well, and seemed to correspond with my sanding effort. A quick experiment in that direction confirmed that repeated sanding would encourage stubborn spots to accept the nickel plating.
Also, while messing with this I came up with a way to selectively plate certain areas of a piece. I wanted to try plating the detailed “arm” piece of the buckle like this- keeping the background brass and only plating the raised detail. I masked off edges with tape, and spray painted the face of the detailed area and allowed it to dry. Then, using very fine sandpaper, I removed paint from just the raised detail, going carefully with light pressure. Then the piece was plated as usual, and paint stripper applied to remove paint from the background. The method worked well, unfortunately it just didn’t look right on this buckle.
Another note, after discussing this project with some folks online, several suggestions were offered to use muriatic (hydrochloric) acid as a final cleaner before plating. I tried this as well with an identical buckle.
I still didn’t get good results without the sanding method. I would like to experiment using muriatic acid as a cleaner in the future, maybe it will give even better results combining the two.
A couple of other notes: higher voltage won’t give you a better result. I found that out the hard way. The very first try was at 12 volts and you can see what that accomplished. This is definitely about finesse and patience, and not willing the project to submission. 6 volts is just right. In that same vein, if you accidentally touch the piece with bare hands, stop trying to talk yourself out of it like I did, and just go clean it again. Your hands are full of oil and dirt, and the time you spend trying to sand away that screw-up is much more than the thirty seconds to give it another quick scrub.