I took 33 empty crayon wrappers, cast them in polyester resin, then turned them on the wood lathe. I also had a few bumps and hiccups along the way...
Step 1: The Casting Process
I made an Instructable about my vase from melted crayons a few weeks back. During that process I learned a trick for getting the wrappers off crayons by freezing them first. I saved a few of the wrappers as they just had an interesting look to them!
Note that this casting will be done in an 8oz mixing cup. It provided the correct shape for a stopper and also eliminated the need to make a special shaped mold.
I used 33 wrappers, as they fit well in the bottom of the mold. To hold them in a cylindrical shape, I added a rubber band around them. My plan was to cast them in epoxy resin. (Let me tell you about the the best-laid plans of mice and men...)
I used about 4 oz of resin, which would net me a 2" square casting.
So... This was interesting. 4oz is not a large casting, but the resin cures via an exothermic reaction. While it's not a ton of resin it got very hot because the heat was contained in 34 containers (the mixing cup + 33 empty wrappers) and there wasn't enough air to cool the casting.
Basically, it got hot. Really hot. It ruined two casting. Anyway... 3rd time was a charm, when I switched to different type of resin. (Polyester instead of Epoxy)
Step 2: Prepping for Turning
After the 3rd casting was sufficiently cured, I cut it up at the band saw.
The diameter of the casting was a hair too big for my chuck jaws, so I had to cut the cylinder into a cube, so I could mount the cube on the lathe and turn it back into a cylinder. It's all very technical.... :)
For bottle stoppers, I use a kit with a threaded mandrel and stub drill bit.
You drill a hole in the bottom of the piece, then remove your chuck, and replace it with a bottle stopper mandrel. It has a self tapping threads that you twist the blank on to, thus achieving a strong hold for turning!
After you've made a few hundred of these, it becomes second nature. Don't ask me how I know that!
Step 3: Turning and Finisings
Turing a wine stopper is easy work, but polyester resin is nasty stuff. A lot more brittle than epoxy resin. I decided to switch from my traditional steel wood turning tools to a carbide cutting chisel.
Even with the carbide, it breaks off like little glass shards and is very hard on the hands. Before you ask, gloves at the wood lathe is a good way to lose a digit.
After turning, I had a pretty cool looking item, but I still needed to sand and polish it.
I wet sanded to 400 grit and then I used my acrylic polishing pads (micro mesh pads) to take it up to 12000 grit.
The difference was amazing. It turned completely translucent and had an effect almost like glass! I'm more than happy with this little trinket and might have to change my feeling on turning polyester resin in the future!
Thanks for looking!