The aim of this assignment was to use a negative and positive molding process in order to cast two ‘finger’ wall hooks.

To make the negative mold, I stirred together 2 ounces of alginate with 8 ounces of water in a paper cup until the yellow-orange mixture was uniform and began to harden. At this point, I shook and tapped the paper cup to remove air bubbles and inserted my right index finger into the mixture for about 5 minutes until the mixture hardened enough for me to remove my finger. This process was repeated in the same fashion to make the second alginate mold.

With the negative molds made, the next step was to mix the plaster that would form the positive products of the molds. I was warned ahead of time that the new type of plaster we were to use took longer to cure than expected and therefore made sure to not use too much water when creating the plaster mixture, which consisted of 2 ounces of dry plaster powder and 4 ounces of water combined in a second paper cup. Mixing the plaster was easier for me than mixing the alginate had been because it became uniform almost instantly without creating any clumps of material.

Since I had both alginate molds made at this point, I then carefully used a popsicle stick to push an appropriate amount of plaster into the negative portions of both alginate molds and shook/tapped the molds to release any air bubbles trapped within the plaster.

Next, I pierced two pieces of tape about a foot in length with one of the provided screws respectively. Each screw was then carefully submerged in the still-wet plaster of the molds and were fastened in place by the tape.

After curing overnight, I used a utility knife to cut through the alginate molds and reveal the positive casts of my finger. I was satisfied to see that neither of them had any noticeable air bubbles and that the intricate wrinkles and folds of my finger were visible.

All in all, I used 4 ounces of powdered alginate ($3.50), 2 ounces of powdered plaster ($0.50), a utility knife ($1.70), 2 screws ($0.05), and an insignificant amount of water, paper cups, popsicle sticks, and tape, resulting in a material costs of $5.70. It took about 45 minutes to create both alginate molds and pour the plaster casts while it took about 15 minutes removing the plaster casts from the molds once it had cured overnight. At a minimum wage of $7.25 per hour, the labor needed to make these casts cost $7.25. Therefore, the total cost needed to make these two finger wall hooks was $13.00.