Hey everyone! This week was the molding and casting unit where we learned how to create molds of our fingers in order to make wall hooks. This was a fairly quick project since we made the actual molds in class and only had to do the post-processing afterwards.
DAY 1: Molding & Casting (1 hour)
During one of our BIOE555 class periods, the teaching staff brought our class through the basics of molding and casting as we used Alginate, plaster, and water to create molds of our two fingers and then cast them both to be left overnight. To create the mold, each person in our class used ~1/2 cup Alginate and ~1/2 cup water to make a mixture that we would then be able to stick our hand in and allow to harden. Once I had mixed the two together and taken out most of the clumps, I put the index and middle finger of my right hand into the Alginate-water mixture and waited for around 20 minutes for it all to harden and dry. After the mixture hardened, I slowly took my hand out being sure to not rip the mold as I did. After this, we mixed plaster with water and poured the mixture into the molds to dry overnight. Lastly, we constructed the screws over the tops of the plaster holes so that the screws would dry into the finger as a finished product.
DAY 2: Taking Plaster Out of Mold (15 minutes)
The next day I had a class in the morning so I went ahead and took the plastered fingers out of the mold so that I could throw away the Alginate mixture. With it being in class, I forgot to take pictures during the process, but included a picture of what my fingers looked like after being taken out of the mold, but before post-processing. I was amazed to see the detail of the finger prints on the mold, but it actually picked up on most of them!
DAY 3: Post-processing (15 minutes)
To post-process my molded fingers I used the dark green spray paint and applied two even coats over the entirety of the objects. The next day, I came in and sprayed a clear coat on them both, but the gloss didn’t seem to take for either of the spray paints applied.
Cost Breakdown
| Cost Type | Cost | Price | Source | Quantity | Total |
| Materials | Alginate | $13.99/ 28 oz. | JOANNE | 50 grams | $0.87 |
| Plaster of Paris | $8.51/ 4 lbs | Amazon.com | 8 oz. | $1.06 | |
| Spray paint | $5.98/ 12 oz. | Walmart | 1 oz. | $0.49 | |
| Labor | Prototyping Engineer (You!) | $20/hour | ZipRecruiter.com | 1.5 hours | $30 |
| TOTAL | $32.42 | ||||
