My good friend and studio mate Aaron (De Land Tree) - his work is pictured above - has been doing a lot of work with electroforming copper structures, and recently helped me plate some 3D prints. It was such a fun and interesting process that I just had to share on the blog.
For my first trial, I selected a model from a previous project. This was printed in ABS on my Up! 3d printer.
Electroplating is a process that uses electrical current to reduce dissolved metal cations so that they form a coherent metal coating on an electrode. This means I need to run electrical current through the piece, so here I've prepped some copper wire to serve as the cathode of the plating circuit.
In order to attach the wire, I first drilled a hole whose diameter is slightly smaller than the gauge of the copper wire.
After pressing it into the hole, friction alone holds the wire in place.
To create a conductive (technically a resistive) surface on the piece, we are using graphite powder. This is an inexpensive material and you can find pretty easily on Amazon.
Aaron discovered a neat trick for ABS prints. Because ABS dissolves in Acetone, we can create an acetone/graphite paint that adheres really nicely to our prints.
I added just enough Acetone to the powder so that it has a watery consistency.
Using a watercolor brush, I slowly built up a couple layers of our "paint" solution. The solution goes on easily and if done carefully, does not disrupt the details of the print.
We then connect the cathode wire to the ground terminal of a rectifier (a switching power supply) and the anode is connected to a chunk of copper.
Both will be submerged into a solution of copper sulfate, which Aaron purchased from Rio Grande.
Here's a diagram illustrating the setup.
Aaron recommends adding a few drops of brightener, also purchased from Rio Grande, to the solution for a smoother plate.
Because the graphite is resistive rather than conductive, you can actually watch the copper begin to creep over the cathode form.
After about 4 hours, the print is plated in copper. Depending on the thickness of copper plating you desire, you can leave it in for more or less time. The initial finish is a bit dull, but that's easy to clean up.
I used a stainless steel polishing bit on a high speed rotary tool to buff the plated print.
This instantly creates a shiny finish on the form.
And here is the finished piece, printed in ABS and plated in copper.
Using an almost identical process, only replacing the copper sulfate with silver solution, and the copper anode with a silver one, we can plate a copper object in silver!
Which of course, I opted for. Silver 3d prints? Yes please! Also, copper will eventually tarnish, so a silver plating will keep the object shiny and happy!
Again, the initial plate comes out a bit dull. Rather than buffing with a rotary tool (which is a bit too aggressive for the thin silver plating) I just use some steel wool to polish the surface.
And the finial product! Printed in ABS, electroformed in copper, and plated in silver. Alchemy in Milwaukee! Thanks for the help, Aaron!
UPDATE: Aaron will be demonstrating this entire process, in much better detail and in person, at the Milwaukee Maker Faire next week!