Test Document 1

Mexico was wonderful

The first step to avoid warping is properly compressing the slab–after rolling it out, we completely compress one side of the slab. We then drape the slab over the form, and compress the other side while it’s on the form. After compression and completing any foot or lip prep (adding spacer), we don’t touch the object until it is quite a stiff leather hard (the form pops out on its own). You should be able to press a finger nail into the clay and leave a mark, but you should not be able to form an impression with the soft part of your finger. Once the clay is a stiff leather hard, we lift it off the form. If it bends or moves in any way after lifting it off, you’ve taken it off too soon. We’ve found that removing the slab too soon is the single most significant factor toward warping the piece. Also try to flip it over before it dries too much in that the ends start curling upward. I’m sure you know how difficult it is to “be there at the right time,” but the importance of removing the piece at the right time cannot be understated. If you are making objects with a lip you must use a spacer.

Use slap roller to compress the clay.
Use rib to compress the clay two different directions on one side.
Add texture if necessary.
Drape, the smooth/textured side down, of moist clay onto form and press gently and evenly to sides to push out any air trapped underneath.
Use rib again to compress clay to the form. Firmly and evenly.
Cut strips of clay using foot maker.
Let piece and foot strips rest for about 20 to 30 minutes to stiffen clay slightly.
Score area to add foot and add water to score marks.
Attach foot strips to create border around piece not more than a half an inch from edge and 8 inches from widest point.
Use modeling tool to clean the places where foot meets the body on all sides.
If the piece has a rim, lift off work surface and place a spacer underneath.
Press the edge of the rim down to work surface to create a slight pitch.
Let piece set for 4-8 hours uncovered in non draft area until edges start to curl up.
Key is even drying not length of drying. Sometimes putting plastic on top creates uneven drying.
Now flip piece over without flexing or stretching the clay and then press on inside center downward to level out any curling that might have happened.
Use wrasp to clean edges and carve smooth any uneven areas.
Use notched rib to burnish the edges even smoother. With non grog clay you could use a sponge to smooth edges but do not get clay too wet.
Now is a great time to add your favorite underglaze or carve into piece.
Let dry and bisque fire. Stacking should not affect warping.

The second most common way the slabs will warp is that there is a draft in your room caused by a fan, heater, breeze or room air flow. Make sure to let the object dry evenly in a still area. Speed is not a factor. Plastic or the use of weighted sacks can also cause uneven drying.

Elva's Memories

2009 PCBeach, November