I never thought I’d ever have (or be asked to make) a mold of my finger.

This project was pretty simple and fairly easy to complete, but it did take me multiple attempts to get the proportions of water to plaster right. In the first attempt I made in class, I used someone else’s plaster to fill my finger mold. I think the plaster mixture had more water than needed because when I went back ~1 day later to check the finger, it was still wet to touch. The next day I checked it again, and it had hardened, but when I pulled the finger from the mold, it cracked and I had to start over.

Overall, the prescribed 1:4 weight ratio of alginate material to water consistently worked over the 3 different molds I made. To make the molds, I first zeroed the scale with the silicone cup on it. Then I added about half of the cup full of the alginate and took note of the weight (g). Then, I added x4 of the alginate’s weight in water and mixed it thoroughly and inserted my finger. I waited about 6 minutes until the mold hardened, then slowly wiggled my finger out.

Next, I created the plaster mixture. I followed the instructions on the bag to combine a 1:3 mixture by weight of water to plaster. I stirred this mixture until it appeared smooth and there was no more powder. Then I poured the plaster into the mold, slightly overflowing it over the top of the finger hole. Next, I used some painter’s tape to suspend a wall screw into the plaster mixture so that it would set in place without falling into the finger.

In one of my attempts, my finger was touching the bottom of the cup, which ended up leaving a mark of excess material on the tip of the finger. The next time, I was careful to keep my finger in the center of the cup and not push it all the way to the bottom of the cup. If I were to do this again, I would probably opt out of using the screw and just create platforms like the finger on the right, below.

 

To finish the pieces, I used a white spray paint to cover all parts of the finger hook. I made sure to wipe away excess paint with paper towels and let it dry overnight. To finish the molds, I used a clear gloss spray paint. Since I used two different molds, and one of the overflow settings worked, my fingers are different but are of the same ring finger.

In the future, I plan to use these possibly as ring holders! And next time I spray paint, I’ll wear gloves..

Cost Analysis:

Combining both labor and material cost, this project would cost about $65.70.

I took about 3 hours to complete this project. At a rate of $20 an hour, the labor cost was $60.

Material costs:

• (2) Screws (negligible)
• (~200g) Alginate casting powder ($5.60 for 200g/3lb bag)
• (~50g) Plaster of Paris = ($0.10 for 50g/25lb bag)
• White and clear spray paint (negligible)