Martz Memories, by
Tools You Can Make
A great advantage for the student- potter is to find a teacher who can show how to make time-saving tools. Karl Martz was such a teacher. Making tools came naturally to him, and while his tool-box (an old fishing –tackle box) did not overflow with gadgets, it did contain examples when he wanted to show the kinds of tools we needed.
Some of those tools were measuring devices. During the semester, there appeared cups of different shapes and sizes, but we soon learned that if we threw cups intended for Karl to examine, they had to conform. For Karl, a cup should contain eight ounces of liquid when filled to within a quarter-inch from the rim. As with the beaker shape, we could rely on him to ask, “Does it lip?”
We could not expect to gain “evaluation points” from a single cup, but a half-dozen matching cups could earn them. To match cups we needed measuring tools and a variety were in use. With potters who had learned to throw elsewhere, inside and outside calipers were popular. Other students had divider shaped rods that could be adjusted to warn the thrower when he was near to the desired height and diameter. But Karl’s students were shown something simpler.
For cups, we stapled or glued a pair of Popsicle sticks in the shape of an elongated cross. These were cut to the height and diameter of the cup shapes to be thrown, although to allow for shrinkage, the stick sizes were cut ten-per-cent larger than the glazed and finished products. Outside calipers were not needed to measure the rim, because practice and eye judgments were sufficient. With the use of our crosses, throwing the basic cup shape became routine, although some students kept more than one Popsicle stick measurer in a toolbox.
Another useful tool that potters collected was the throwing rib. The rib replaced the hand or fingers where more strength or a smooth surface was required. Class colleagues thought collecting ribs could be over-done, but I could always look at one of my throwing ribs and tell how and where it was to be used. Most of the ribs sold by pottery tool suppliers were of boxwood, made for use on the inside of bowls and rounded shapes. They did not help me make plates. Most of my plates needed a smooth and flat interior, and I saved or made wooden ribs to fulfill those requirements.
Even for bowls and globe shapes, I discovered items in unexpected places, some that could be adapted to serve a special need. Looking at offerings in a shoe repair shop, some rubber heels captured my attention. A suggestion went through my head. “With a little modification---,” I thought. That afternoon, a rasp file curved and thinned the rounded part of a heel to give a thin and flexible edge. The heel body provided a large area to grasp, and it assisted me to press the rib against the clay. The device was ideal for bowls and globes. Karl saw my rubber heel modification and gave a smile of approval.
Thank you for your encouragement, Karl.