NAME: Michelle, Yijun, Diana, Tony
DATE AND TIME: 14 October 2014, 9AM to ~12PM
LOCATION: 260 Chandler Hall, ColumbiaUniversity
SUBJECT: Sand casting

Using recipes p118v for the sand and p118v_b2 for the sand mold in a box, we began sand casting. Since Yijun and I had our plaster casts ready to go, Tony began working with us first. We first sieved about three cups of sand into the finest sieve we have, and then added a ¾ cup of the ammonium chloride water along with a silver spoonful of e&j brandy. We mixed the sand and water with a wooden spoon, and found it very difficult to mix as the sand wasn’t taking the moisture very well. When Tony thought it was wet enough, he scooped out the sand and rolled it out with a wooden rolling pin. It turns out that the sand was much too wet to our surprise; we learned from this first batch that very little water should go into the sand, and the balance is very delicate. Also, the best way to know when the sand was ready is to roll it in your hands and squeeze it. It should not be too wet and leave sand on your palm, and it should also take a very nice impression of your palm as well. The recipe notes that the sand should be “moistened…in order to give it a nice hold, though it still came apart easily,” which I thought to be a good description of the kind of sand that was best for the molding. With this first batch we ended up adding another two cups of sand into our mixture, and then it was deemed dry enough for the molding process.
Once we finished with the sand, we then dusted off our plaster medals with burnt and crushed charcoal, and then placed them face up in the first half of the wooden box mold. This half would be flipped over to meet the masculine side, so that the impression we pressed into was on the outer edge and the back of the medal would meet the other half. From there, I began to press the sand into the mold, careful to press very well into the details of the medal. I covered the whole thing with sand, scraping off the excess with a knife, and then dusted charcoal all over the finished first half. I then finished pressing sand into the other half of the mold once I joined up both sides. Once I finished, I left it to sit for awhile and awaited Tony’s judgment.
However, I kept encountering more and more moisture build up, and when Tony came to inspect my mold and pried it open, we found that the sand was too wet and the impression did not take at all. It looked like a mess, and I was honestly frustrated; the work had taken more energy than I thought it would, and I wasn’t looking forward to repeating the whole procedure again. However, I rolled up my sleeves and went at it the second time with Yijun. What we did differently the second round:
-I made sure that I mixed the sand with my bare hands. Because we had mixed the sand with a wooden spoon the first time, I really felt that the removal from direct contact with the sand made measuring the moisture impossible. With my bare hands, I could feel when it was getting too wet or when it was getting to the right texture, and we used less water than we previously had before.
- this time, the ratio was 4 cups of sand to ¾ ammonium chloride water and spoonful of brandy
Once I repeated the whole procedure and made the mold, I was afraid that I would have to yet again make the mold anew, since it was still very wet the second time around (though less wet than the first time). However, Tony suggested that we leave it overnight in a zip lock bag, and I left it there to come back the next day.

NAME: Michelle, Tony
DATE AND TIME: 15 October 2014, 10AM-11AM
LOCATION: 260 Chandler Hall, ColumbiaUniversity
SUBJECT: Sand casting, continued

I came in around 10AM to take a look at my mold, hoping that it had taken well. Tony took my mold out so we could inspect the final product. It separated well enough, as it had dried overnight. Some of the impression of the back of the mold was stuck on the other half, but only very little.
Because the sand had dried around the plaster, it was difficult to remove the plaster medal from the sand. Tony first carved the entrance out to the plaster and tried to pry it out from there, but it did not budge. He then carved around the medal with a small knife, removing some sand surrounding the medal, in order to better get the plaster out. From there, some wiggling around got the plaster medal out of the sand.
What came out, to my delight, was a very nice impression of the profile into the sand. All the ridges came out into the sand, to my surprised, since the first attempt erased any sort of detail or shape. I truly believe that leaving the mold over from the night before allowed the sand to really mold around the design and take the image, even though it was more of a pain to get the plaster out. Tony finished up my mold by adding some wet sand around the rim of the entrance, and I was finished for the day. My sand was ready for metal casting.