This week, we learned the basic processes of how to mold and cast an object. With this, we were tasked to mold and cast our fingers for creative and very personalized coat hangers!
Process:
During class on Thursday, we created the mold for the finger and filled it with plaster for the first finger. We measured 33 g of mold and 125 g of water according to the instructions and mixed the ingredients together in a silicone measuring cup using a stirring stick. We made sure to stir the mixture until there were no clumps of mold left and everything else was even. Then, I stuck my finger in and waited for approximately 3 minutes until I could wiggle my finger and remove it easily from the mold.
The next step was mixing the plaster, which was a 1:2 ratio of water and plaster. I used the measurements on the silicone measuring cup and mixed 10 g of water into 20 g of plaster. This was a lot easier to mix and make even compared to the mold mixture. Since I used the larger cup for molding, I had to use a stirring stick along with the nail holder to secure the nail inside the plaster. I then moved on to pouring the plaster into the mold and securing the nail inside.
For the cleaning, I made sure to not run anything down the drain and wipe all the cups out with paper towel. I also made sure to wipe my hands down twice with wet paper towel before washing them with soap.
I made sure to come back the next day to remove my first finger out of the mold and pour in my second one. Because the mold already started to water a little, it was quite easy with a little squeeze to pull the plaster finger out of the mold. I followed the same processes in pouring in the plaster and securing the nail for my second finger.
I came back the next day to remove the second finger out of the mold. It turned out slightly worse than the first one because there were some air bubbles in the plaster, which is maybe a result of using the same mold twice. I dried both fingers and left them in my box to dry out more (both fingers were wet when being pulled out of the mold). I also cleaned up the large container and ripped out the mold into the trash.
After a few days, I worked on the post-processing of the finger hangers. I had to sand down the fingers a little on the base and tips so that it would be a little smoother. I made sure to not over-sand the texture of the skin and make it look less like a finger. (also cleaned up after sanding)
I decided to spray paint it grey, which seemed like a fitting color for a coat hanger. I used our metal cut Texas pieces and taped one side together to create a spray painting stand for the fingers. I then applied two layers of gray spray paint and two layers of semigloss finish, leaving 20 minutes between each spray according to the instructions on the spray can.
After it dried completely, now we have the final product: two coat hangers! If you look closely, it is pretty visible which one was done first and which one was the second with the air bubbles. From that, I learned that it is better to not reuse this type of mold and recreate one if needed for a second one. However, the spray paint and semigloss finish made the fingers look cool!
Cleaned up workspaces:
Cost Estimates:
- Silicone Measuring Cups: $18.36 (sur la table)
- Alginate Powder 33g: $4.98/ounce * 1.164 ounce = $5.80 (amazon)
- Plaster of Paris 40g: $0.08/ounce * 1.41 ounce = $0.11 (amazon)
- 2 screws: $0.13/screw * 2 screws = $0.26 (amazon)
- Popsicle sticks: $0.04/stick * 4 sticks = $0.16 (amazon)
- Spray Paint 2 cans: $5.98/can * 2cans * 1/10 = $1.20 (walmart)
- Sand paper: $0.22 (amazon)
- Labor as a Design Engineer: $31/hour x 1.5 hours = $46.50
Total: $72.61
