Tuesday, August 17, 2010

mold work on the Terre Haute commission

This is my 100th blog posting! The clay work for the Terre Haute family group was approved. The next step is to make molds of the sculpture and send them to the foundry, to become bronze.

The sculpture must be cut into pieces, to make it manageable for making molds and pieces that the foundry can pour at one time. We removed the heads first, using a wire tool.

Next, we used a sawzall to cut off the arms, which were then mounted upright onto waiting boards with pins. It is intensely nerve racking to cut up a sculpture that I've worked on for months.

Then, the children were cut up and removed, leaving the two adult torsos and legs. When everything was cut into handleable sizes, there were 17 separate pieces to be molded.

The mold work was turned over to Don and our neighbor, Steve McMillen. Steve helped Don on the Home of the Innocents sculpture groups last year. Steve is mixing the 2 part rubber Polygel 40 that we buy from Polytek. Even though we bought the mold compound in 5 gallon buckets, they pour the compound into separate quart cans, to keep down spillage. Notice the plastic sheet - mold making is messy, no matter how careful you are.

The first coat is the most important, as that picks up the surface details. You have to make sure that the rubber compound is pushed into every crevice, and that there are no bubbles.

After the first coat becomes hard, but still tacky, they apply a second coat. When it has gone off, but still tacky, thet apply the part-line shims. They use bubble sheet from sculpture depot in Loveland, Colorado. The sheet is cut into long strips, and those strips get smeared with trewax. Don is cutting the bubble sheet to follow the contour of the sculpture. He makes cuts where the curves are too sharp for the strips and tapes the pieces together with a special tape that we get from sculpture depot. The strips are attached to the sculpture temporarily with straight pins, right through the rubber coat and into the clay.

"...there's no place like home..."

They mix up a regular batch of rubber (equal volumes of part A and part B), and then mix in this light fluffy stuff called Polyfil 2 that we get from Polytek. It makes the rubber compoung stiff, like cake icing. They put it into a plastic baggy, cut the corner and apply it along the seams. Don uses a knife to smooth it out. They have seen people use a short cut by squirting a bead along the drawn-on part line and stick in plastic shims, without the fuss of cutting, taping and pins. It's a little sloppy, so they prefer to take the extra steps.

A third, fourth and fifth coat is applied over the shims and sculpture pieces. Then, they mix up more rubber with polyfil (to a thick icing consistency) and apply it with a plastic knife to areas that have any undercuts. A plaster mother mold will be applied to each mold. Those mother mold pieces have to come off easily, so there can't be undercuts that will hold the plaster.

A final sixth coat is applied, as sometimes the surface of the polyfil mix can be rough. The manufacturer recommends that you only start what you can finish that day. Don and Steve have finished 11 out of 17 pieces at this point. When they finish the rubber work, they will apply the plaster mother molds.

Sunday, August 15, 2010

Grizzly Bears Shape Up

I shape the bears using angle grinders with diamond blades. I don't use air-hammers, except in areas where I can't get a grinder.
This is the rear-end view of the mother bear. This is where the third cub will be.

With the high temperatures, the bear needed to be moved into the new studio. But first, the rails had to be laid down properly. The weight of the bear would make this difficult, so the bear had to be removed from cart. A brick truck was hired to take it off, and then when the tracks were laid, the truck come back and returned the bear to the cart.
Don and the operator of the truck are pushing the bear into the studio where she can be worked on in relative comfort.
I make cuts where I will remove stone from around the standing cub.
I have removed some of the stone, and marked with a china marker, where the bears legs will be, though I always cut wide, to leave room if I need it. I use the maquette to eyeball points, and mark these as well. I draw on the mothers foot where different things line up - cub's belly, ear, etc. and mark a line, so I can be sure the cub is positioned properly. I do this from different angles to make sure of it's position.
The cub is beginning to be blocked in.
This is where the cub on the mother's belly will be. I use existing shapes in the stone to guide me in placing the cub. He will be on his back with his feet braced against his mothers legs, playing with his litter mate. This will be the slowest area to progress, as the faces of the two bears have to relate.
This is the sculpture from the right side. Next, I will be carving in the anatomical structure of the bear.

One of the snacks on hand is Cheezits. Each cracker has a hole in the center. This is Don as seen through a Cheezit.
Pine Ridge Road is a round about way to get home. It is a little rustic, going through three creeks - if the water's high, forget it. But it's a really pretty drive. These Swallowtail Butterflies were in one of the creek bottoms. After some mineral I suppose.

I think this is a Giant Swallowtail. The only one in the group, or is it flock of butterflies.