Molding and Casting My Fingers! | ENGI 210: Prototyping and Fabrication

For this week, we were tasked with creating a mold of our fingers using an alginate and water mixture, then casting these molds using a rockite and water mixture. I used my right index and middle fingers as the two fingers I wanted to mold, simply because I thought it would be easier to do so. This blog documents the process by which I completed this week’s project, including both the failures and successes.

To start with, I followed the directions on the assignment by measuring and mixing 6.75 ounces of water and 1.5 ounces of alginate. I mixed the mixture for roughly five minutes, until I felt it begin to thicken. Then, I inserted the intended fingers into the mixture and waited for five minutes until the mold was constructed. Once the five minutes had passed, I slowly removed the mold to ensure it would not deform. After this, I created the Rockite and water mixture to pour into the mold of my fingers, which would serve as the casting process for this project. I gathered 35 grams of Rockite and 10 grams of water, mixed well for a couple of minutes, then filled the two molds. After this, I got the 3D print to support the two screws that would be inserted within the Rockite mold. Then I let this mixture settle and dry before removing it. However, I did not wait the recommended time before removing the cast from the mold (I forgot), and when I pulled the mixture out, it had not thoroughly dried, and the end product did not resemble my fingers. And I had to restart the process again. But in the process of removing the Rockite mixture from he alginate mixture, I deformed the original mold and therefore could not use it again. Once I realized my error, I followed the same procedure I listed above and generated another mold, allowing me to finally move on to the final part of this project.

First attempt

After the cast was removed, I was left with two fingers that had very slight bumps and rough patches, which I sanded down with 400-grit sandpaper, resulting in no prominent holes or imperfections. Then I added a layer of spray paint to both fingers and let the coat dry overnight. Once all was said and done, I had finished molding and casting my fingers!