ART 35  ~  SCULPTURE: CASTING

Handout #6: CERAMIC SHELL: Name__________

DIPPING and INVESTING SHELLS; DIVESTING BRONZE PIECES DIPPING SHELLS

  1. Cup procedure: Take a small paper cup, carefully stick the metal pipe through the center of the bottom, screw white coupling w/handle onto pipe on the inside of cup. Fill the bottom of the cup up with hot wax. Allow to cool, then coat pipe and cup with wax.
  2. Gate the finished wax pattern in the "Direct" method (HO#4) to wax on pipe and bottom of cup. Refer constantly to the Gating Checklist (HO#5), especially Step #9. Once the wax pattern has been successfully gated, the piece is ready to begin 'Dipping.'
  3. Put on your dust mask. Remove lid and turn off mixer. Check that the ceramic slurry is in good condition: well-stirred and creamy. Hold the piece firmly by the handle, and completely coat the piece, including gating and cup, with slurry. Allow to drain off at various attitudes for 15-20 seconds, keeping as even as possible.
  4. Quickly move piece to vented drum and begin sifting stucco on surface of piece. Keep moving the pattern to avoid puddling (on the piece and in the tank) as you sift. Cover entire surface of piece, gating and cup.
  5. Carefully hang piece on rack, rinse hands, turn on mixer and cover slurry with lid. Wait until thoroughly dry, then brush off excess stucco, and repeat steps C & D.

INVESTING SHELLS

  1. Making Baskets: Measure the diameter of the widest part of your piece. Multiply this times 5. This is how long a piece of chicken wire you will need to wrap around your shell with 1 inch on all sides. Measure the length of your shell, including cup. Add 1 inch. This is the height of your basket. Cut paper to cover basket. Multiply first number times 7, to wrap around basket twice. Same height as chicken wire. Use 3 pcs. bailing wire to secure paper to basket. Use chalk to label: Name, #, temp.
  2. Investing: Put down large silver tarp. Get out buckets, plaster and sand--set up brigades for each. (Plaster and water at 2/3 full, sand to top.) Set baskets in rows, with room to work. Pour (1) water into large bucket, add (1) plaster, allow to sit 1-2 minutes, or until air bubbles stop. Stir. Add (1) sand, stir out all lumps. Coat outside of baskets to tarp. Once set, fill baskets by repeating, plunge shells. When set, remove bailing wire, paper and any excess wax or cups. Clean up!

DIVESTING BRONZES

When the bronze has been poured, the investments may be moved once the cups have turned black. Remove the wooden flasks, break away excess sand, and use tongs to drag outside, being careful not to disturb unpoured pieces. Always wear: Dust mask, Eye protection and gloves. The pieces are still very hot! Carefully break open the investment by using an adze to cut away wire down one side, and splitting open. Chip away plaster to expose your bronze casting! It may be dipped in water to clean. Shovel all the investment and wire into the dump truck. Sweep and throw away debris, rinse area. Put away sand, flasks, tools.