This project was definitely an interesting task as I never thought I would use my finger as inspiration much less a hook. From the initial casting/molding class, I learned what the incorrect composition for both alginate and plaster was which allowed me to do much better in my second trial. I worked with Taylor on this project and we started by mixing alginate powder with water in a 1:4 by weight (This ratio is very important so we decided to weight the components to obtain the most accurate ratio possible. I believe we used about 50g of alginate each with the corresponding 200g of water. We later learned that you should add the powder to the water instead of the other way around to ensure that powder is not left unmixed at the bottom of the container. After mixing enough quantity for both of our projects, we split the mixture into two smaller silicone cups. Immediately, I placed both of the fingers that I wanted to cast into the silicone cup. I wanted to expedite this process so instead of repeating the same process twice to get two finger replicas, I decided to get both fingers at once. The fingers will be slightly different, but they’ll be similar enough as they are both mine. After waiting about 10 minutes (which felt like much longer) with both hands in the mold, the alginate had solidified enough that I could remove both of my fingers. The mold looked good, so we moved on to mixing the plaster.
For the next part of the process, we mixed in plaster in larger amounts to obtain enough plaster for both of our molding projects. We followed the stated ratio (2:1 by volume plaster powder to water) until a viscosity similar to thick peanut butter was accomplished. We had our guest instructor Taekyeom Lee from Iowa State University double check our consistency before moving on. I poured the plaster into the mold and waited a few minutes before inserting the nail. I did this so that the nail would be suspended in the plaster without falling through as it would have set ever so slightly. Additionally, before inserting the nail, I tried to level off the plaster so that the top was as flat as possible.
I waited a day before removing my finger hooks from the mold to guarantee the plaster had fully set. To ensure the fingers wouldn’t break (as my in class finger had), I removed the alginate mold (with the plaster fingers still inside) from the silicone container, and with the help of a blade, cut the mold to release my plaster fingers. I honestly was very impressed by the detail that the mold had been able to capture.
Still, there were some imperfections like air bubbles that were visible. In the future this can be fixed by either mixing the plaster in a vacuum or by knocking the mold against the table before the plaster dries. Additionally, the top (now bottom of my plaster finger) was not as flat as I wanted it to be. However, using some fine sand paper I was able to get rid of some of the external air bubbles and also flatten the edges. I didn’t want to sand too much as I still wanted the little details to come through. To finish the post processing of my finger hooks, I decided to spray paint them one black and one white. I used a couple of layers of spray paint each and would dab off some excess paint that would cover the details too much. As an extra level of protection, I also added a clear glossy finish coat to the fingers. And here is the final product!
Cost Analysis
- Labor cost: 1.5 hr of working time @ $20/hr → $30
- Alginate: $40 per bag but used only a little → $1
- Plaster: $30 for 25lbs but definitely used less than 0.5lb → $0.60
- Nails: negligible as it was taken from the extra stock at the OEDK
- Spray Paint: $5/can but used very little → $0.50
- Gloss Finishing Spray → $5/can but used very little → $0.50
Total cost → $32.60
