Wood carver’s bench screws are 3 inch
long steel screws used to fasten a carving block and hold it securely to a workbench. The carver would clamp a board onto the work surface, and run the screw through the board and into the piece of wood being worked on. When carving is completed, the piece is removed from the screw and mounted for display.
Canvas rolls are used for holding miscel-
laneous loose wood carving and stone carving tools if they have no wooden set container. The rolls may also hold rasps, and even steel tools for mold making and some ceramic tools. (These last two, however, are usually carried in a plastic case since water is used in mold making and ceramics.) They are of roll type heavy canvas secured with tie strings, double stitched on the seams, and are available in 6-, 9-, 14-, and 22-pocket sizes.
Dust Mask
Respirator
6-Pocket Roll 9-Pocket Roll
Aprons are like chefs’ aprons with specially
designed pockets for holding various wood carving, stone carving, and ceramics tools. They fall just above knee level and have a cotton tie string fastened behind the back. At one time they were made of leather, but, due to the cost and scarcity of this material, most aprons are made of heavy denim today.
Sand bags are meant to brace or secure a
large piece of raw stone or wood so that while carving it will not shift and fall over or move - like padding furniture when moving. They can be arranged like pillows on a couch for comfort if you take a rest. Normally made of
heavy canvas, they are approximately 8" by 10" in size and usually have Velcro closings or securing devices.
They are sold empty. While you don’t have to put sand in them you should put some ma- terial in them that will give a little. I imagine
that 4 sand bags should be sufficient to balance Sand Bag
PART 4
CHAPTER11
OTTERY CLAYS AND CERAMIC CLAYS ARE VIRTUALLY THE SAME; they are all made with a water base and need to be fired in a kiln to vitrifica- tion to become permanent. The primary types of clay bodies are earthenware and stoneware which turn red, brown, or white when fired. Specialty clays such as Raku and porcelain are used by the more advanced potters.
Clay used for pottery is indigenous to only certain regions of the world and every manu- facturer uses the same base clay. United States clay body formulas are generally a mixture of several different types of clay, derived primarily from clays mined in Georgia, Tennessee, Ohio. Small amounts of darker clays that make up a formula, such as Van Dyke Brown, are found in New Mexico. Clay mined in California has a gritty coarse texture and therefore, is not usually used in formulas. Fine grolegg clays from England are used for making porcelain clay bodies.
The manufacturer develops a formula or recipe and mixes the ingredients with a rib- bon blender or pug mill, adding water. Some producers have a vacuum chamber on the extruding end of the mixing machine to de-air the extruded clay, thus calling the final product
de-aired. However, I recommend that all clay,
when taken from the container, be wedged, that is, remove the air pockets before using and firing in a kiln to make sure no air is captured in the final piece to be fired. In the kiln, as the heat gains in temperature, gas may form in the air pockets, causing them to explode and ruin the piece. Experienced potters have all had this happen at one time or another.
Some formulas I know of have very unusu- al additives, such as vinegar, to the mix. I have not noticed that this makes much difference to the quality, smoothness, or outcome of the finished product, but who knows? Bentonite is the only additive I know that enhances a clay body, making it more plastic without the nor- mal aging process (where the clay is allowed to set for a few weeks to let the molecules migrate).
Special formulas are made up by potters
who experiment with various raw materials
P
POTTERY & CERAMICS
over time. They express individual preference, serve generally as a signature of the potters, and are kept very secret. Special formulas can be developed for both glaze and clay. When using anything other than a standard clay or glaze, test both the clay and glaze to ensure they match. If they are not compatible, trouble will ensue when the piece is fired. It is a good idea, when a new clay and glaze are going to be used, to make test tiles of the two to be sure there will be no problems.
Slip is a liquid clay with suspension addi-
tives that enable the clay to be cast into plaster molds made of pottery plaster for its water absorbency. The mold is filled with slip and left about 3 hours to absorb the water from the clay until a thin skin about 1/8 inch thick has formed. The remainder of the liquid clay is poured out and the resulting cast of clay left to harden. It is then removed from the mold and when dry, the seam lines from the mold are trimmed and the piece is bisque fired. Glaze is then applied and the piece is glaze fired. The piece is now completed. Figurines, plates, and ash trays are commonly done in this manner, as well as most porcelain pieces. On mass produced items you will see seam lines where the pieces of the mold have been joined together.