This week focused on molding techniques. We specifically focused on making negative molds, then filling them to make positive results. In a surprise turn of events, I had almost no problems this week! Turns out molding is much more straight forward than some of the computer programs that we’ve used in the past. I ended up doing two molds due to some imperfections in the first one, but overall it wasn’t too hard to get a good mold.

Step one was mixing the algernate. During class I had practiced mixing the algernate so I knew the approximate ratios. The ratio of water to powder is 1-1, but the powder doesn’t expand the volume as much as plaster does. Therefore I put enough water for about 75% of the volume as water and then the rest of the volume would be algernate. I also used a small cup because I was just molding a finger and I didn’t want to waste material. I also have really small hands so it worked out.

Step two was mixing the two parts of the 300Q. I didn’t take a picture because it mixed so fast. Once it started setting up it needed to be in the mold or it would be useless. I tried to only mix as much as the volume of my finger.

The image on the left was my first attempt. I learned several things from this attempt. I ended up getting a bubble on the underside of the finger hook I was creating. I was able to fix this issue the second time around by pouring a small amount of the 300Q mixture in the mold and swirling it around to cover all sides before pouring in the rest.

The other thing I learned is that I had way too much water in my algernate solution. I found this out by my algernate not completely drying as well as water built up in the bottom once I removed it from the cup. I created a much thicker solution on the second attempt and alleviated this issue.

 

These are the two trials side by side. The first attempt is on bottom and the final is on top. Key highlights to notice is how the bottom mold is much more porous, with a lot more bubbles on the surface of the plastic. This was due to the uncured algernate of the first solution because there was too much water in the solution. Additionally the impression is not as good and doesn’t hold as much detail as the one on the top.

 

 

This is another picture of the final, next to the position of my hand to show the accuracy. The plastic was able to pick up a lot more detail than I was originally anticipating.

Overall I learned a lot about molding this week that will help me with the final project.