CHAPTER XI: MAKING LARGE PIECES

There is a limit in size beyond which the non-professional will not be able to go. Men of life-long experience can throw very large jars but this involves not only more practice than the artist-potter can hope to secure but also great physical strength. On the other hand it is perfectly possible to form vases two or three feet in height by doing the work in parts or sections. No one need fear to put such a plan in operation on account of sentiment. It is, of course, worth while to make large wares in a single piece but section work involves great skill and, as a rule, the result attained is better. Work made in one piece is apt to be badly finished, especially inside, and unduly heavy. Work made in sections can be thrown with thin walls and finished with proper care. If tradition be of any help, be it known that the Chinese have used the piece method for hundreds of years, and that the Greeks used it three thousand years ago.

The first requisite is a drawing either actual size or properly scaled. The measurements should be those of the soft clay and if a particular size be desired in the burned piece, the shrinkage, probably about one-eighth, must be added. The drawing must show the size of each section with the points of junction, and should indicate the upper and lower edges in each case. Some divisions are best made right side up; some are more easily thrown upside down. Care should be taken that the faces which are to be joined are thrown under similar conditions. In every piece of work one face rests on the bat, the other is in the air or free. A bat face should always be joined to a bat face and a free face to a free.

Suppose, for instance, a vase is to be sixteen inches high and is to be thrown in four divisions of four inches each. The bottom division is made first. This will stand in its normal position, right side up. The second section must now be thrown upside down, because, if it were not, its bat face would be joined to the free face of the first piece. So the sections are thrown alternately, every other one being inverted.

As the pieces are thrown they must be carefully measured to see that the faces which are to be united are the same size. The height of each piece also must be gauged and adjusted. The bats with their contents are now set aside to harden. As soon as they can be handled with safety the clay pieces should be removed from the bats upon which the throwing was done and set upon dry bats which will absorb the moisture and help to stiffen the clay. It is a good plan to pile the sections up as they are to stand in the finished piece, one upon another and to leave them so in a cool place for ten or twelve hours. The faces which are to be joined will thus acquire a uniform hardness and unequal shrinkage will be avoided.

When all is ready for the turning, the sections being of the proper hardness are taken in hand. This work should not be hurried. It will take a whole morning to put together a large piece. First, the bottom section is placed on the wheel, centered and made to run true as regards the top edge. It is then inverted and the foot is properly finished, signed and dated. Then the second joint is likewise turned true on both faces, the inside turned smooth; and so on, each piece in turn is prepared for the fitting, the measurement of each face being accurately adjusted. At this stage it is possible to correct the diameter of the faces to some extent either by pressure as the wheel revolves or by building up with soft clay. In either case, however, the new work must be hardened before proceeding. The whole piece is now put together carefully but with dry joints. It should be slowly revolved on the wheel and the proportions carefully criticised. If satisfactory it is taken apart again and the actual fitting up may proceed.

The bottom section is again centered most carefully on the wheel and steadied with three pieces of clay. A thick slip is now prepared, the same clay as that used for the work being of course, used. This slip must be quite free from lumps and should be as thick as molasses. The upper edge of the work is carefully sponged with clean water and a good coating of slip is applied at the junction. Care must be taken that every part of the face is covered with slip. The second joint is now moistened at the junction and set in position upon the bed of slip. It is placed very lightly and the wheel is gently revolved to see if the running is true. If so it is pressed home and the superfluous slip is removed. The joint should be quite close like a glued joint in carpentry.

In the same way the third section is placed upon the second and the fourth upon the third. It is now possible to work over the face of the vase with a little soft clay. There is almost always some irregularity in the line, especially at the joints, and this must be adjusted while the work is moist. Then the whole face is gone over with turning tools and sponge and the vase is set aside to dry. It must not be expected that large pieces, made by any method, will be produced with as much ease as small vases and bowls. The risks are much greater and, owing to the size of the work, the faults are much more apparent. When the vase is perfectly dry it should be set on the wheel, centered and slowly revolved. If it is very untrue in its motion there is no remedy. It should be broken down and the clay used again. A very slight irregularity may be corrected by rubbing off a little clay on one side of the foot but this cannot be done to any considerable extent. The courage to break unsatisfactory work is never more valuable than at this juncture. It will pay in the end, for no imperfect piece can be a source of satisfaction to the conscientious craftsman.