For this assignment, our goal was to use alginate and plaster to create 2 copies of one of our fingers. 

First attempt:

We did our first attempt of molding our fingers in class. The TAs showed us how to mix the alginate and plaster, and explained the curing time for each material. I created a mold of one of my fingers in the alginate, poured in the plaster after it set, and stuck a nail into the plaster held in place by tape. 

I came back the next day to check on my finger. Immediately, I knew I’d have to redo it because the plaster was damp and the nail didn’t end up in the finger at all. Even though I was able to de-mold my finger all in one piece, it was unusable because the plaster had absorbed water from the alginate. I had let it sit for two long before taking it out of the mold. 

Second attempt (molding):

For my second attempt, Mina and I worked together to hopefully create high quality replicas of our fingers. We gathered all the materials we needed, then did our best to piece together what we remembered in class with the instructions in the homework document. We first made the alginate, using a 4:1 ratio of alginate to water by weight. We used 400g of alginate and 100 grams of water. However, after mixing our alginate, we realized that we only had enough to fill one cup. We each stuck one finger in to hopefully get at least one good molded finger out of this batch of alginate.

We then doubled the amount of alginate (800g water, 200g alginate), and had enough to fill a cup for each of us, and some leftover for another classmate. I tapped the cup of alginate on the table a few times to try to get as many air bubbles out as I could, then stuck my two pointer fingers into the alginate. 

After our molds had set, we removed our fingers and made the plaster in a 2:1 ratio of plaster to water. During this time, we were also setting up our nails, so the plaster had thickened a bit by the time we started getting it into our molds. We had to scoop the plaster in, but eventually filled our molds and put the nails in.

Second attempt (post processing):

When I removed my plaster fingers from the mold, they were attached at the base by excess plaster. I used a small saw to separate them, then a combination of files, rasps, and sandpaper to do more precise removal of excess material. Unfortunately, the finger the first mold me and Mina made was missing the entire top third, so there wasn’t much I could do to salvage it. 

However, I wasn’t fully satisfied with how my fingers had turned out: the excess material took away from the overall look, and there were a few air bubbles. 

Third Attempt: 

I decided to try one more time to see if I could get a better result. I repeated all the steps from before, except this time, made sure to pour the plaster before it got thick. I also removed the excess plaster I had poured in before it set so I wouldn’t have to deal with as much extra material after it dried. Third time really is the charm, because these fingers were definitely the best yet. After taking them out of the molds, I only had to file and sand off a little bit of material. 

Final Post-Processing:

I decided to paint the fingers from my second attempt and third attempt, but at some point I misplaced one of the fingers from my second attempt, so I only ended up painting three. I screwed the screws into small foam cubes to hold my fingers up to make it easier to spray paint and display them. I decided to do a base coat of blue, then added some pink and gold. After the paint dried, I added a clear coat and was done! 

Takeaways:

• This was definitely an assignment where a lot of small things could get messed up, so it sometimes takes a few tries to get everything how you want it.
• Somehow, even after molding at least like 5 fingers, I never managed to put my arm in a position that was comfortable to hold for the 8 or so minutes it took for the alginate to set.
• I really like how my fingers turned out. I’ve been looking forward to this assignment for a while and it didn’t disappoint! 

Cost:

• Alginate: $1.15/oz *  about 4 oz = $4.60
• Plaster:  $0.10/oz * about 5 oz = $0.50
• Spray Paint: used very little, about $1
• Clear Coat: used very little, about $1
• Labor: $15/hr * 3 = $45
• Total: $52.10