DIY Network

Web Extras: Throwing Wide Bowl Forms and Making Test Tiles Web Extras: Throwing Wide Bowl Forms and Making Test Tiles From "Throwing Clay" episode DTHC-105

Here are some simple tips on throwing wide bowl forms and making test tiles.

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• As you prepare the clay to be used to make your bowl, establish in your "mind's eye" its details: What dimensions will it have? What will the rim shape be? What will the base or foot of the bowl look like? Preplanning keeps the throwing steps organized.

• Once the form is centered, opened and ready to pull upward, use a minimum amount of water during the pulling process. Too much water will quickly saturate the clay and cause your bowl to sink and collapse.

• There are three wheel speeds involved in throwing large bowls: use a quick wheel speed to center and open the form; a medium wheel speed through the wall-pulling step to securely get the basic, thick-walled bowl shaped; and a slow wheel speed as you carefully put the final curve and finish into your thin-walled, completed bowl.

• Use a maximum of three pulls to draw the wall of the pot upward to half its finished height.

• Use an additional three pulls to draw the walls upward again and slightly taller than the finished bowl will be.

• Use two to three pulls to widen the bowl. Finally, using a light touch, create the finished inside curve of your bowl.

Glaze Test Tiles

Testing glazes is essential to expanding your palette as a potter. Here are some tips.

• There are three basic ways to make test tiles: hand building, throwing and extruding. You will want to texture the surface of whatever type of test tile you choose to make. These surfaces will show you how your test glazes flow and pool over a texture.

• Be sure to use the same type of clay for pots and test tiles. The same glaze can look very different on different types of clay.

Hand-Built Test Tiles

1. Roll out a 3/8" thick slab and apply a random texture across its surface. Now cut the slab into 3"x3" squares and punch a "hang up" hole through one corner of each "tile."

2. Another option is to cut the slab into 1" strips; roll each strip around a narrow cardboard tube, connecting its ends. Press and flatten one side of each "tile ring" to keep it from rolling.

Thrown Test Tiles

1. Throw a low, wide cylinder, 2-1/2" to 3" tall, without a base or floor (figure A).

2. As you throw the cylinder, create a ledge at the foot of the cylinder wall, inside and out. This ledge will keep your glaze test tiles standing upright (figure B).

3. With a knife, cut the cylinder into 2-1/2" sections, like a pie. Punch or cut a hole near the top of each test tile. This hole is useful to hang each test tile on its glaze bucket or to hang the tiles on the wall in the glazing area of your studio (figure C).

Figure A

Figure B

Figure C

Extruded Test Tiles

1. Extrude a length of square, hollow clay (figure D).

2. Lay this extruded form onto a table; measure and mark it off in 3" segments; cut along the marks and separate each segment. I use a simple wooden template "jig" to cut my extruded lengths. This straight cutting tool keeps the tiles level and square. I also cut through the tile with a very thin wire, rather than a knife. This thin wire keeps the hollow extruded shape from collapsing during this cutting step (figure E).

3. Add a stamped texture to one side of the tile and punch or cut a "hang up" hole opposite (figure F).

Figure D

Figure E

Figure F