Molding and Casting Zek’s Finger ! | ENGI 210: Prototyping and Fabrication

We started off our molding and casting homework assignment, by going over all the steps in making a mold using alginate and filling it with rockite. During the tutorial in class, my partner was the one who got to make her mold and her first set of casting. So I had to come into the OEDK later in the week to do my mold and casting.

When I started on my finger casting, I made sure to collect all the materials needed: flexible cups, a scale, alginate, rockite, water, 2 screws, and popsicle sticks for mixing. I used the measurements on the given instructions below, and began mixing up 1.5 ounces of alginate with 6.75 ounces of water. Since this scale did not have the hundredths displayed, I measured my water to be between 6.7 to 6.8 ounces. After measuring my ingredients, I slowly poured the alginate into the water and stirred continuously to avoid any clumping. Once my mixture was done and felt the right consistency that we observed during class, I put my finger in to be molded.

I waited around 5 minutes for the mold to harden around my finger. The alginate felt bouncy, but firm in holding the shape of my finger. I moved on to mixing 35 grams of rockite with 10 grams of water for casting.

After having my rockite mixture ready, I slowly poured it into my alginate mold at an angle, doing my absolute best to avoid air bubbles. With my rockite set in place, I placed one of my screws into the rockite while it was still wet, and held it in place with popsicle sticks and the screw holder as shown below:

I let my finger cast harden for a full day, and repeated the rockite process one more time with the same mold after taking out my first finger. The next day, I took out my second mold, and let them both dry off on a paper towel for a few days. Due to the moisture inside the alginate, both casting came out feeling a little wet, so they needed to dry outside a little before I could post-process them.

I started my post-processing by sanding down some of the bumps on my fingers. I used 280 grit sandpaper, and smoothed the bumps as much as I could without taking away from the texture of my actual finger. There are still some visible imperfections; however, I feel like this is inevitable especially as a beginner in molding and casting.

After sanding down both of my fingers, I decided I wanted my screws to keep their original colors. So, I taped the screws to keep them covered during the spray painting. I picked out a pretty pink spray paint from the EDES 210 spray paints, and got to work with spray painting my fingers outside.

I let the spray paint dry outside for 2-3 hours, and came back to the OEDK to take off the tape from the screws and finish up my homework assignment. After taking off the tape, I saw that some spray paint did get on the screws, but I was able to quickly clean it off with some alcohol wipes.