Tuesday, April 5, 2011
Arms Mold Nº 3
Well, I changed my mind again. I decided that the clay build-up I did yesterday was too complicated. I only have a very limited amount of moulage, so the flatter, the better.
This is a piece of cereal box cardboard with the profiles of the upper arms cut out, and the old wax upper arms placed in the cut-outs. I sealed the cardboard with a couple of coats of shellac before I put the wax patterns in the cut-outs.
This is a back view of the cereal box cardboard build-up. I have sealed around the edges with some oil-clay.
Next, I added some spares, for pouring the carving wax into the mold. Then I built-up an oil-clay wall to hold the moulage.
I put the board at the top of the mold, and braced it with another piece of wood, all of which had some oil-clay stops to keep things from moving.
Here is a better view of the brace and the oil-clay stops. It doesn't take much for such a small mold.
I did support the cardboard build-up with some wooden blocks and some oil-clay coils placed underneath. It looks really flimsy in this photo, but it worked.
I added an oil-clay registration key for the moulage between the upper arms. It is easier to key flexible mold materials before they are poured. I also added another wooden stop at the bottom of the mold, with a few pieces of oil-clay to hold it in place.
Then I melted the moulage in a double boiler and poured it into the oil-clay area that I made for it. Once it setup, I removed the oil-clay walls, put my wooden coddles around the cardboard build-up, then mixed some plaster and poured it over the moulage, for a mother mold. Yeah, I found 2 pounds of plaster in the studio by scraping out my plaster box. That was just enough to make mother molds for each half of the moulage. In this photo, the oil-clay retaining wall for the second half of the moulage mold is shown. I've also added the other half of the spares.
Once the second half of the moulage mold was poured, I removed the oil-clay walls, carved registration keys in the first plaster half, applied parting agent to the first plaster half, then put the coddles around it, and mixed and poured the second plaster mother mold over the second half of the moulage mold.
This is a photo of the finished mold, ready for pouring some carving wax into. It is far from perfect, but it worked! I soaked the plaster pieces in water before pouring the carving wax. I removed the excess water from the mold halves before pouring the carving wax.
Here is the mold, banded up to pour the second set of carving wax upper arms. I used the SurForm tool to bevel the edges of the plaster mother mold. The first set of cast upper arms can be seen in the right hand corner of the photo.
This is the mold right after I pured the third set of carving wax upper arms.
The first set of arms came out solid. I waited too long before trying to pour out excess carving wax. I did not wait as long on the second set, and got some more wax out. I got quite a bit of liquid carving wax out of the third set. I'll see how all of these work. I made three sets so I can experiment on them.
I am opening the third set of carving wax castings. The first half of the plaster mother mold is on the left side. The first moulage mold half is still around the castings. I had to remove the moulage mold at an angle each time because I did not have a separate mold piece for the sockets in the arms.
The first half of the moulage mold has been removed, showing the castings embedded in the second half of the moulage mold. All the registration keys are clearly seen in this photo. When making molds, two important things to remember are registration keys, and a suitable parting agent. I did not have to worry about the moulage because it does not stick to anything, not even itself. I used a 50/50 liquid soap to water mixture as a parting agent for the plaster.
Showing the modeling wax upper arms in one half of the mold, and the third set of carving wax castings in the other mold half. This mold worked good. I can use all of these carving wax castings for testing.
The moulage is reusable, so I cut it up into cubes and put the cubes back in the glass jars and sealed the jars tightly with a good lid. I think I bought this moulage back in the late 1980's, or early 1990's, I can't remember. If stored properly, it seems to last a really long time. I love reusable materials.
I'm going to clean up the studio tomorrow. I remembered to turn off the wax pot, and anything else that cannot be left unattended.
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