I had a couple of old USB drives lying around and decided to free them from their cases and give them a new life. Seeing the circuit boards made me think it was a shame to cover them up, so I decided to cast the USB drives in resin. This protects the circuit board without hiding it, giving a very cool look.
I had never cast epoxy before, so it was a bit of trial and error, but I figured it out in the end. I really like how they turned out. The epoxy is super clear and I love how they light up when they're in use!
What you'll need:
- old USB drives with the casing removed
- something to use as a mould
- epoxy resin
- digital scales
- sandpaper up to 800 grit
- spray lacquer
- super glue (to fill any gaps)
- exacto knife (to trim the edges)
Step 1: Make a Mould
I dug around the house for something I could use as a mould and ended up with this plastic case for spare knife blades. I cut it up and glued two pieces together to close the bottom.
Step 2: Prepare the Mould for Casting
Most articles I read about casting resin in plastic moulds recommend using a special mould release spray, but I also came across a few other options. For my first try, I used pure petroleum jelly and a top coat of hairspray inside the mould.
Step 3: Mix and Pour the Resin
I'm using a clear epoxy resin, which needs to be mixed in a 2 to 1 ratio. After a good stir, I poured it into the mould and placed the USB drive inside. I used some clay to keep it from touching the bottom.
Step 4: Wait...
The drying time is supposed to be 24 hours, but it was still liquid the next day. Epoxy relies on the heat it generates to help it cure, so maybe the amount I'm using is simply too small. I set the mould on top of our room heater to see if that helped and the next day the resin had cured.
Step 5: Take It Out of the Mould
Popping the piece out of the mould was surprisingly easy. After removing the bottom I pushed a thin exacto blade between the mould and resin to allow some air in and then I could simply pull it out.
It looked really nice, but there were quite a few small air bubbles on the outside that had clung to the mould. There's also one side that didn't fill up completely. So for my second attempt I made the mould upside down, so the opening would be bigger. I used polymer clay to close it up around the USB drive.
I mixed up a new batch of resin and poured it in. I also added a bit more resin to the first one, to try and fill that hole.
This time I also used a small torch to get the air bubbles out. This was a bit tricky, since I didn't want to melt the mould. I also burned the clay a bit. But there were some big bubbles coming out, so it seemed to work.
I didn't use anything as a mould release this time. It was harder to remove from the mould, but still came out fine. No real difference in air bubbles though. The upside down mould may have worked against me there, trapping air below the USB drive.
Step 6: Superglue to the Rescue
There was a significant dip in the second casting where the resin was pulled towards the mould walls. A taller mould could have prevented that. Anyway, I can't really mix such a tiny bit of resin, so I tried filling the gap with superglue. That worked very well. You can see the transition line, but it's not very noticeable.
Step 7: Finishing: Sanding and Lacquer
To remove those air bubbles on the surface I worked my way through the sandpaper grits.
I went up to 800 grit, which made the surface feel very smooth. Once I dried them off though, they're not as clear anymore. So to finish them, I added a coat of spray lacquer.
And that's it. I love how these came out and had a lot of fun using resin to upcycle my old USB drives.