When I first discovered that electroplating 3d prints was possible, I got very excited. The idea that you can print something to a specific design, and then give it metallic properties was interesting to me.
There are a few reasons you would want to electroplate a 3d print.
1. It increases the strength and rigidity of the part.
2. It's conductive.
3. It's pretty.
A note on the conductivity. It's a common practice to use electroplating to make double sided PCBs with through hole components by electroplating the inside of the hole. Sure you can just use solder and some wire, but that's way less cool.
You can electroplate many different kinds of metals. They each have different requirements and benefits, and some can be quite complicated. So for this walk through I'm going to be demonstrating copper and nickel. Both of which are fairly easy to do (And so far the only two I know how to do :] )
Copper, just like silver, has the drawback of tarnishing over time. If you leave either exposed to oxygen for too long the finish will dull and possibly even discolor. I haven't tried it, but I bet if you covered the copper in some sort of varnish it will prevent the tarnish.
But if for some reason you don't want to do that, or you want a silver finish, nickel is the common choice. Nickel doesn't plate well directly to the 3d print. It works far better if there is a base layer of copper, and then the nickel is plated on top of it. But Nickel doesn't tarnish. And it's a good poorman's alternative to chrome. Since chrome is more complicated to successfully plate.
Let's start with copper plating.
For a 3d print to be electroplated, the surface needs to be conductive. There are a couple of clever ways that I've seen this accomplished. You can buy conductive filament (Which is expensive). You can mix graphite power with acrylic paint (Which is a very attractive option with some nice benefits). Or you can mix acetone and graphite power to make paint that only works on ABS.
Preparing the printed part
The process that I chose is using ABS with acetone and graphite. Graphite can be bought online, and if you're lucky at a local artists store. It's not very expensive, and the bottle will last you a really long time. Acetone can be picked up at your local hardware store.
Once you have your to ingredients, you'll mix them together in a glass container. A Mason jar works really nicely. The proportion doesn't really matter. You want it thin enough that it can paint smoothly, but not so thin that it doesn't completely cover the printed part. I'm using white ABS so that it's very obvious when I don't completely cover the part. If you're not using a light color, just make sure that you coat it fully. Side note, it's a good idea to not touch the painted part with your bare fingers. The oils in your hands can cause the part to plate unevenly.
After the paint has dried (Which should take a few seconds) use some fine steel wool to buff the painted surface. You can be pretty rough with it here. The graphite binds pretty tightly to the abs. If you do happen to scrape off the paint, reapply, and buff a little more gently.
Preparing the plating solution
For plating copper I use a mixture of copper sulfate and vinegar. Traditionally sulfuric acid is used instead of vinegar. but for small setups like this, I'm not so sure it's necessary. But the solution being acidic helps improve the conductivity, and helps maintain the copper ions in the solution.
Plating
Finishing
The final result! It comes out rather rough, and needs some good polishing. But it's solid copper. You'll notice some parts didn't plate at all. I'm not exactly sure why. It may be because it's a deep "concavity". Or it may be that when I rubbed it with steel wool I didn't get in between the letters well enough. Either way, I think I'll be able to do some selective plating and touch it up
I happened to have a brass brush tool for my Dremel, so I decided to give it a try. I think it turned out pretty nicely.
No comments:
Post a Comment