Weird… The only way I can describe this project is with the simple word “weird”, as exemplified by the expressions on my friends’ faces when I told them that I was molding and casting my finger for ENGI 210, or by Dr. Hunter’s grin when she saw me with my finger in a cup of alginate. This was definitely an interesting idea to introduce molding and casting, and looking back, it makes chuckle every time I think about it.

I started by preparing the alginate mix. I achieved a 4:1 water to alginate ratio by weighing 50 g of alginate and 200 g of water in different plastic cups with a scale. Even though alginate making is not an exact science, and the measurements did not need to be so precise, I was unable to break free from the shackles of my mild OCD. As such, it was unnecessarily painstaking.

I then poured the water into the alginate and started mixing vigorously with a popsicle stick. I made sure that I got all the powder stuck on the sides of the cup. After 4 minutes, I dunked my right index finger into the mix to form the mold. I tried to bend my finger to more closely resemble a hook, but I made sure that it was not too bend so as to be impossible to take out of the mix without breaking it.

I proceeded to wait until the mix pushed back like jello whenever I poked it. I then removed my finger carefully, preserving the shape of the now solid mix. It was time to prepare the plaster mix, which was a 2:1 plaster to water ratio. As such, I mixed 43 g of plaster with 86 g of water and poured the mix in the mold.

To put the screw in position, I made it puncture a piece of tape that went around the sides of the cup. This allowed the head of the screw to dip into the plaster mix, which would then solidify around the screw.

Now that I had prepared my first finger (I never thought I would say such a sentence), it was time to repeat the process all over again. I made another alginate mix and stuck my finger in it. However, I did not realize that my finger was barely touching the wall of the cup. As such, the mold was defective, and I had to make another.

While making the (now third) mold, I tried to have my finger in the same orientation as it was in the first mold. However, I knew that was humanly impossible. The only way to produce exact copies of a cast was to use a reusable mold, potentially one that could open and close without breaking. That was outside the scope of the proficiency level I was going for (mainly due to time constraints and a heavy workload). I then poured the same mix of plaster I used for the first finger because it was not dry yet, even though more than 30 minutes had passed.

I waited for another 20 minutes when I realized that something was wrong. The plaster mix in the molds were forming two layers: a white, opaque layer on the bottom and a translucent layer on the top. I looked back at the instructions and noticed the critical mistake I had made: I had mixed a 2:1 water to plaster ratio, when it should have been the other way around. As such, the plaster mix was not solidifying. I swiftly and appropriately dumped the contents of the molds and proceeded to prepare another plaster mix. This time, I mixed 35 g of plaster with 15 g of water, and I poured the mix into the molds. In hindsight, 35 g of plaster was excessive; I overestimated the amount I needed, and I could have used way less.

I came back in 90 minutes to remove the cast fingers from their molds. The first finger was quite successful, with the exception of a few bubbles that formed on the surface of the cast. The second, on the other hand, was still wet that it broke in half. My heart sunk. I thought that I would redo both to get a higher quality cast for the first finger. I asked Dr. Wettergreen what I should do to prevent the formation of bubbles, but he said it was “great” and did not need to be further improved. As such, I decided to only make one other finger, again…

I went through all the steps in the exact same manner to produce the final (fingers crossed) finger. I was more careful with tearing the mold, and it worked! I now had two fingers, alongside the 10 that are attached to my hands (pardon the terrible joke).

Taking inspiration from those who completed the project before I did, I used a piece of foam to support my finger hooks. I cut it and sanded it, and I pushed the screws into it. I then used a clear coat to protect the fingers from any potential external sources of damage. I opted against using flamboyant colors because I did not want such uncanny objects to look even more unnatural than they already are.

And the final verdict is: a success! The casts are shockingly detailed to the last wrinkle. Unfortunately, they are not identical because of inevitable human error: one was more bent than the other. I also could not prevent the formation of bubbles in both; I may have introduced a lot of air into the plaster mix while I was mixing it, and a more gentle stir in the shape of an 8 might have mitigated or eliminated bubble formation.

MONEY TIMEEEEE 🤑

I will only be considering the materials that went into making the final products when calculating the cost (the materials that went into the failed parts will not be taken into account, as that is unfair to the fictitious consumer).

• Alginate powder: $49.97 for 3 pounds. 50 g were used, resulting in a cost of $5.51.
• Plaster of Paris: $8.83 for 4 pounds. 35 g were used, resulting in a cost of $0.68.
• Plastic cups: $8.49 for 100 cups. 4 were used, resulting in a cost of $0.34.
• Popsicle sticks: $5.99 for 100 sticks. 4 were used, resulting in a cost of $0.24.
• Screws: $7.99 for a 230 piece kit. 2 were used, resulting in a cost of $0.07 (assuming all screws cost the same).
• Foam: $30 for a 0.5″ x 4′ x 8′ piece. An approximate area of 4″ x 2″ was used, resulting in a cost of $0.05.
• Tap water: Free 🙂
• Labor: $10/hour. A total of 3 hours was spent, resulting in a cost of $30.

The final product with the two fingers combined costs $36.89.

 

brianbishara