DIY Network

Assembling the Pieces Assembling the Pieces From "Throwing Clay" episode DTHC-105

Figure A

Master potter Bill Van Gilder is making a chip-and-dip bowl. First, he threw a large bowl from five pounds of clay and added a decorative twist to the rim. Next, he threw the two-piece goblet, composed of a bowl and stem, from a three-pound lump of clay. He measured the goblet to be sure it would be an inch taller than the rim of the bowl once the pieces were assembled. When the pieces were leather hard, he trimmed the large bowl and cut an air hole in the bottom of the bowl so the assembled piece won't explode in the kiln. Now it's time to assemble the pieces (figure A).

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1. Before attaching the stem to the small bowl, Bill has to smooth the edges of the bowl, a process that requires attaching the bowl to the wheel head. The typical method of attaching the bowl to the wheel uses three pieces of coiled clay; he has a more efficient approach to trimming the bowl. He dampens the wheel head and the rim of the small bowl and then places the rim of the bowl on the slowly turning wheel, where it slides around briefly, until the surface becomes tacky and attaches itself to the wheel head. He centers it and lightly taps it in place. The vacuum that's created underneath and inside the bowl holds it tight to the wheel head. Now the bowl can be trimmed without bouncing the trimming tool off the coils of clay (figure B).

2. Trimming leaves the clay surface rough. Bill uses a rubber rib to burnish the surface, leaving a smooth, silky finish on the clay (figure C).

Figure B

Figure C

3. He wets the base of the stem and scores the base of the bowl with the trimming tool. The rough edge he creates will ensure a secure bond between the bowl and the stem (figure D) (figure E).

Figure D

Figure E

4. Bill centers the stem and pressures the top edge of the goblet stem down onto the base of the bowl. At the top, he isn't putting much pressure on the inside; he is putting pressure on the rim to pressure the stem down onto the bowl.

5. The rubber rib is used to reprofile the piece and a sponge is used to wipe any moisture off the clay.

6. The clay is still somewhat soft, so care is taken to lift it from the wheel head. To keep from squeezing the clay, Bill slides the bowl to the side, breaking the seal with the wheel head, without distorting the shape. The rim of the small bowl is now approximately 1" above the rim of the large bowl (figure F) (figure G).

7. The pieces must now dry to a bone-dry consistency. When dry, they are placed in the kiln, where they are fired separately. They are nested, stacked and fired for 10 to 12 hours at 1750 degrees. After firing, the kiln cools for at least 24 hours before being unloaded (figure H).

Figure F

Figure G

Figure H

RESOURCES :

Kilns
L & L Kilns
Website: www.hotkilns.com

Clay
Highwater Clays
Website: www.highwaterclays.com

Extruders
American Art Clay Co. Inc. (AMACO)
Website: www.amaco.com