Field notes on plaster casting 10/13:
I carved my wax mold into a fleur de lis, carefully trying to make sure that I carved at an angle that would be most suitable to mold into clay and then pour with plaster. Tonny was very adamant that we not undercut the mold. Here is the mold after it was molded into clay.
I used dish soap as a release agent for the mold, placing it on the clay before putting the wax mold into it.
For a two-sided mold (like Jenny's), the plaster was more the consistency of pancake batter because of the need to pour it. For a one-sided one, it was more like a heavy cream/mustard. The clay and wax molds were a little slanted and not quite level, so I had to put a tool underneath one side to keep the mold level while pouring the plaster.
After the plaster was poured, Tonny and I decided that it would be okay to
put it in the toaster oven to dry, so that it would be ready to cast in sand soon after. Here is what it looked like upon completion:
It needed a bit of filing but was soon ready for casting in sand.
The next day, 10/14, Ray and I began to sift the sand to try to make the proper consistency of sand for sand casting. We were told to try to make a consistency of sand that would be wet enough to be moldable, but not crumbly (the test is to throw it up in the air and see if it crumbles or breaks apart when it lands back in your hand). Sand was sifted to remove chunks and then combined with filtered water, sal ammoniac, and a dash of brandy (we figured a "silver spoon" is like a teaspoon).
It was quite difficult to get the sand to the right consistency. We overestimated the amount of water we needed slightly, and we had to add sand to our formed lump of sand to adjust the consistency.
Unfortunately I was not able to put my medal into the sand by myself due to larger space/time concerns, but here is a photo of it in the sand, and before metal was poured:
My medal did not come out as well when poured in silver. Unfortunately the sand in the mold was not dry enough, and therefore when the silver was added, it created too much steam and caused a (very small) spray of liquid silver. In the end, did not cast fully and had a large hole where the steam prevented the medal from filling. Such is life, I guess!
When the box was opened, my medal really wasn't discernible as anything really other than a bunch of silver fragments. I couldn't even tell which one it was in the lab to be able to take a picture of it!