Resin casting


Photo of a full-size-skull (front half) made of translucent resin, with embedded ramen noodle block in the brain area, and chatter teeth in the teeth area, held up to the sun so the light shines through the translucent resin from the back.
Photo of a person in a dark room, wearing a necklace of TTRPG transparent resin dice lit up from inside with LEDs in various colors

I completed two resin casting projects recently: a full-size skull, and a light-up TTRPG dice necklace.

Memento mori (skull)

High-level resin casting steps are: measuring the resin components, mixing them together very slowly to avoid introducing air bubbles, pouring, adding embeds, and allowing the resin 2-3 days to cure. Pouring more than one inch or so at a time can cause the resin to never harden, so I poured shallow amounts each time to make sure the whole 4-5″ deep object hardened equally. This project took 4 days of 1 resin pour per day, plus an additional final 3 days of curing.

Setting up and using PPE:

The brain is half a dry ramen noodle block; the teeth are novelty chatter teeth with the chatter mechanism removed.

The mold is the size of an avergae adult skull, but because it’s intended for baking cakes it’s divided in half. I wasn’t sure making two halves and gluing them together would look good, so I just made the front half. In the future, I can try that. I could also glue the two mold halves together and make a small hole for pouring in resin at the top, though that would make adding embeds difficult, and the mold would be ruined after one project.

The skull was supposed to have large googly eyes embedded under the eye sockets, but they migrated under the nose during curing.

You can see the googly eyes set back behind the nose, in the second photo below. I’m considering gluing on googly eyes to the outside of the cast (photo 4), but might just leave it without googly eyes, as I think that probably looks best.

Lit dice necklace

I used a string of LED fairy lights and silicone TTRPG dice molds to make a light-up necklace:

Resin learning

My previous resin attempts yielded nothing worth keeping—some never cured all the way, and others had too many air bubbles. Knowing the skull would use a lot of resin and days of pouring and curing, I made some changes to my process that seem to have helped:

  • new resin (not bottles that had been opened a while before)
  • using a timer while mixing (avoids counting matching stirring speed, which should be very slow; avoids “surely it’s been 3 minutes”)
  • using tape to hold embeds in place until resin cures around them (though this proved too difficult to manage with the googly eyes, without the tape also touching the resin and getting hardened into it)
  • generally more care, slowness, laying supplies out before use, frequent cleaning to keep my gloved fingers unsticky when manipulating things, and covers/airflow to avoid dust

I didn’t predict the outside of the skull resin would be frosted, given previous castings’ transparency; but I expect that’s due to something about the different silicone mold I used for this project.

I haven’t achieved rollable resin dice yet. LED wires coming out of one die face gets around the challenge of getting the top of the mold to closely match the other die faces. In the future, I’m hoping to carve my own dice molds out of a solid block, as the squeezability of the dice-shaped molds made it difficult to latch the lid on without too much resin getting forced out.