I’ve always been interested in 3D printing in different materials or even possibly coating prints with paint or metal. During my time at UVA’s architecture school, I printed in nylon, wood filament, and many other crazy materials. I’ve also tested smoothing ABS with acetone vapor (works wonderfully). However, I really wanted to try something new, especially now that Techshop was at my disposal. My friend/coworker Brett runs an electroplating class, which I decided to take one day after work. Basically, the idea of electroplating is to use an electric current to coat a conductive object (typically some sort of metal) with, well, a different type of metal. It’s extremely useful and can be used for many different things, such as to decorate, to harden objects, or to protect from corrosion. In Brett’s class, we plated a copper penny with nickel- the process was far simpler than I originally imagined. You mix together nickel acetate (easy buy from Amazon) with vinegar in a plastic container. Once that’s all nice and mixed up, you connect whatever you are trying to electroplate (in our case, copper) to the cathode aka negative side of a small power supply (6V battery) and the metal you plan to electroplate with (nickel) to the anode aka positive side. Place both in the nickel acetate vinegar bath, turn on the power supply to about 4 V (best to keep the voltage low) and wait. You will begin to see a coating form over your penny!
I was extremely pleased with the results and wondered if I could somehow use the same technique to coat a 3D print. I did some research online and saw that many people had tried it and got some pretty awesome results. It seemed that the cheapest method was using a graphite based coating, which would make the 3D print conductive. I decided I would try out a combination of acetone and graphite powder- the acetone, in theory, would cause ABS plastic to melt a bit (remember acetone vapor smoothing) and therefore act as a adhesive for the graphite. I purchased some graphite powder and acetone and mixed it. Oh my goodness, the graphite got everywhere! My hands were covered in this stuff for days. But, the mixture turned out very well in my opinion. I found an old ABS print I didn’t mind testing on and coated it with my solution. Here is how the solution looked and the graphite powder I purchased (noticed I kept it in a plastic baggy at ALL TIMES):
Once it was coated, I used the same method as Brett showed in class, but rather than connecting a copper penny to the cathode, I connected my graphite covered 3D print (well, I wrapped nickel wire around the print to ensure it was secure and connected that the cathode). Unfortunately, I did not take any photos of that rig, but I do have a picture of how it turned out:
First try went way better than I expected. I honestly didn’t think it was going to work at all (my coworkers at Techshop had their doubts as well). The dark gray areas are places that didn’t take the nickel, but the lighter areas are locations coated in nickel- success! Now that trial 1 was over, it was time to move on to bigger things. Such as JEWELRY.
I designed a basic parametric bracelet in grasshopper and printed it on a Stratasys Mojo. It came out with a lot of support material, so it had to sit in the bath for a while. Here it is covered in support:
Afterwards, I coated the bracelet with my acetone graphite solution. I did about 3 coats since the design was so complex; I had to ensure I got every little crevice. Here it is as I’m beginning to coat it:
Alright, now it’s time to electroplate it! I set up the rig and connected the 3D print using A LOT of wire. I then carefully placed it in the nickel acetate bath and let it sit for 7 hours. It’s like watching paint dry:
Here you can finally see what the rig looks like. That rectangular object is my chunk of nickel, connected to the anode of my power supply. I had to rotate my bracelet every so often since my solution didn’t fully cover it. You can see the nickel beginning to cover the print:
After seven long hours, I pulled the print out and was amazed at the results and how well the graphite took the nickel. Of course, it wasn’t perfect. There were areas of the print that didn’t take as much and some areas looked a little clumpy. Additionally, the metal was not polished. I purchased some Simichrome and used that the polish it up. It actually worked pretty well. Here is an image of the final product:
Pretty cool stuff. I plan to test it on other objects, but for now I’m pleased I created a new trendy bracelet I can wear 🙂