Fun With Hot Wax
Sep. 30th, 2008 06:26 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
peteyfrogboyAs promised, more wax casting experiments.
Here's the melting pot I described in my last post:
Here are the plaster molds:
Here's the important trick for casting wax in plaster molds:
You have to soak the mold in water for about 10 minutes so that the plaster will be saturated. Otherwise, the wax will get into the pores of the plaster and not release. The hotter the water, the better, to avoid chilling the wax too quickly.
The other trick I tried, which seems to work pretty well, is applying the wax first with a paintbrush. This helps to get the wax into the fine details of the mold without having shrinkage problems. A thick layer of wax will shrink more than a thin layer. I don't have a picture of this part of the process, but if I do it again, I'll try to get one. Basically I laid the two halves of the wet mold out on paper towels, poured a little bit of hot wax into the mold and then smooshed it around with an old paintbrush. I kept doing this over each part of the mold, building up a couple of layers of wax. It's important not to fill the mold up completely, so that you can put the two halves together and pour more wax in to weld the two sides together. Here's the result:
I got really sharp detail on my side, and only lost a little on the other side. There were a few voids where I didn't quite get enough wax in the letters, but I was able to fill those in easily. The bits of detail I lost I redrew with a sharp wooden sculpting tool. With a little more practice, I think this technique will work very well.
Here's the melting pot I described in my last post:
Here are the plaster molds:
Here's the important trick for casting wax in plaster molds:
You have to soak the mold in water for about 10 minutes so that the plaster will be saturated. Otherwise, the wax will get into the pores of the plaster and not release. The hotter the water, the better, to avoid chilling the wax too quickly.
The other trick I tried, which seems to work pretty well, is applying the wax first with a paintbrush. This helps to get the wax into the fine details of the mold without having shrinkage problems. A thick layer of wax will shrink more than a thin layer. I don't have a picture of this part of the process, but if I do it again, I'll try to get one. Basically I laid the two halves of the wet mold out on paper towels, poured a little bit of hot wax into the mold and then smooshed it around with an old paintbrush. I kept doing this over each part of the mold, building up a couple of layers of wax. It's important not to fill the mold up completely, so that you can put the two halves together and pour more wax in to weld the two sides together. Here's the result:
I got really sharp detail on my side, and only lost a little on the other side. There were a few voids where I didn't quite get enough wax in the letters, but I was able to fill those in easily. The bits of detail I lost I redrew with a sharp wooden sculpting tool. With a little more practice, I think this technique will work very well.