For this project, I molded and casted my fingers. I used an alginate mold, which preserves incredible detail of the fingers, and a rockite cement cast. Although the project seemed simple at first glance, like always, it somehow took longer than I expected, due to phenomena I entirely did not expect.
I started out by gathering all of the materials I needed, listed out below:
- Alginate powder
- Rockite powder
- Popsicle sticks
- Mixing cups
- Two scales
- Two wood screws
- Jig
This is a lot of stuff, so it’s important to gather it all beforehand
I began by weighing the appropriate amounts of alginate and water to create the mold. I followed the recommended amounts of 1.5 oz alginate and 6.75 oz water. I immediately noticed this was a huge amount of alginate, but I kept going. I mixed for about 3 minutes. I dipped my fingers in and kept them still for 5 minutes. As an attempt to make the fingers ‘equal’ without having to create two separate molds, I dipped both of my index fingers at once. This was problematic because in doing so I stretched the mixing cup past the bounds of the mold, leaving a gap between the mold and the edge of the cup.
You can see the gap in the left mold
I decided to mix the rockite anyway in an attempt to preserve this attempt. I used the recommended amounts of 35 g rockite and 10 g water. The rockite ended up seeping into the gap, so this attempt was not one that I would keep.
In my second attempt I wanted to change two things: 1) I wanted to use less alginate since I felt the amount in the document was excessive, especially for multiple attempts, and 2) I wanted to ensure that I wouldn’t create a gap in the mold again. My solution to the first problem was to use 33 g alginate and 125 g of water, another recommended ratio. To solve the second problem, I used my index and middle fingers of one hand, deciding to forgo the effort of making them appear ‘equal’. I kept the same ratio and amounts for the rockite.
34 g of alginate
127 g of water
The recommendation for 35 g rockite and 10 g water was for one finger, so for two fingers I used 70 g rockite and 20 g water.
20 g water
70 g rockite
I created the mold and the cast, and it was successful. The only issue I had with this attempt was that the spacing between my fingers was too small, so the screws wouldn’t sit near the center of the base of the finger.
You can see the right screw is off-center
While I was waiting for the rockite to cure for this attempt, I decided to try a third attempt to fix the spacing, although not entirely necessary. To do this, I measured the distance between the two screws and determined it to be 3 cm. Before dipping my fingers, I planned to space my fingers so that the bases were 3 cm apart. I successfully created another mold. Now to create the casts. This is where the most unexpected issue occurred. I had been outside for a few hours by this point. I used the exact same amounts of rockite and water, but when I mixed them, this happened:
The rockite was hardened into chunks and would not mix
I thought I had made a mistake in zeroing the scale or using the wrong amounts. I also considered the possibility that I had initally poured the rockite into the water instead of the reverse. I tried the exact same thing again, this time pouring the rockite into the water slowly, but it eventually turned out the same. I even tried mixing amounts suitable for one finger; that is, 35 g rockite and 10 g water. Still, it turned out the same. I did some research and found that even a tiny bit of humidity can completely ruin a batch of rockite. I had been outside for 3 hours and the humidity was 92% (can you guess what time it was?). It was safe to say I wasn’t going to get another attempt done, so I settled for the casts that had been curing for that whole hour. The rockite cures in about 40 minutes, so it was ready to be taken out.
Completed cast
Next, it was time to post-process the casts. I feel that sanding, even a fine grit, would ruin the intricate details, such as the fingerprints, so I did not do that. I spray painted the fingers blue. This was probably the most impossible shape to spray paint. I had to spray paint one side at a time, but when I turned the fingers over, I would inevitably spray paint a portion that had already been painted, leading to uneven coats. After a few coats I decided to finish it off by standing them upright and doing another coat. I then added a semi-gloss clear coat.
Spray-painted fingers
After a lot of cleaning up, here is the clean workspace:
