Tuesday, March 22, 2011
Carving Wax Feet Nº 1
I started working on the mold for the feet and forgot to take photos until I'd already poured the plaster in the first half of the mold. As you can see from the photo, I used my studio-made coddles. I used thin coils of oil-clay to seal the seams around the inside of the coddles. I applied a coating of parting agent. I also put some clay balls around the outside of the coddles, to help keep them in place. I mixed my plaster using a 2:3 ratio of water to plaster. I turned on the vibrator prior to pouring the plaster. I cleaned my hands, mixing bowl, and tools in a bucket of water. Never put any plaster (dry, wet, or set) in the drainage pipes!
Here is another view of the freshly poured plaster, from the top.
This is a closeup of the brown wax feet in the clay build-up. You can see how I made the clay build-up around the feet, using coils of oil-clay.
Whoa! Look at that! That was a close call. The build-up was about 2mm short along the edge of this clay wall. Luckily, no plaster went inside.
The little bridge that you can see was added as a spreader to keep the clay wall from deforming.
Another view of the mold from a different angle.
After an hour had passed, the first half of the plaster mold was set up. I coated the inside with some orange shellac. The clay build-up around the feet has been removed, leaving the clay build-up for the parting line around the bottom of the feet. The pouring cup, and sprues are left in as well, for the other half of the mold.
This is another view of the mess that I made.
I don't know if it can be seen in this photo, but there is plenty of draft in that hole. The moulage will be poured in the hole.
Here, the first plaster mold half is placed over the feet on the molding board.
Then it got busy again, and I didn't remember to take any photos. I melted the moulage in a double boiler, then let it cool down somewhat. I put rubber bands around the plaster and molding board to hold them together. Moulage doesn't stick to anything, so I didn't need to apply any kind of parting agent. When the moulage was about 140 degrees Fahrenhet, I turned on the vibrator and poured the moulage into the hole. Then I screed off the excess. That completes the first half of the feet mold, which is made from plaster and moulage.
After the moulage cooled down (lunch time!), I removed the oil-clay build-up from around the bottom of the feet, then I poured the bottom half of the plaster mold. I used the coddles again, and sealed the inside seams with thin coils of oil-clay. I waited for the plaster to setup, then I soaked the two plaster halves in water to prepare for pouring the carving wax. I put the moulage mold piece in a plastic bag to help keep it moist.
I scratched some air vents for the toes in the second plaster mold half. Here are all three pieces, ready to be put together and poured.
This is a close-up of the air vents.
This is the moulage mold piece sitting inside the plaster couch, or Mother Mold.
I melted the carving wax in an old aluminum pot, then poured it into the rubber banded mold until the pouring cup was full. Then I let it cool. The feet are being poured solid.
Here are the carving wax feet from the first pour. You can see the air vents worked good. All the toes came out, with toenails and everything.
This is a view of the bottom of the feet from the first pour.
This is yet another view of the feet from the first pour.
Between pours, I soaked the plaster mold halves in water, so the molten carving wax wouldn't stick to them.
I ended up pouring three pairs of feet before the mold finally disintegrated to the point where I was reaching diminishing returns. I think three pair of feet will be enough to do some test stringing with.
Considering that I wanted to get at least two pair of carving wax feet from this mold, I did well to get three pair of feet! I will have enough for test stringing, as well as other experiments.
I ran out of plaster making this mold, so it was a good decision to change my mind from making a 6-piece plaster mold, to making a 3-piece plaster/moulage mold.
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