Trimming
Trimming removes excess clay from the bottom of a
pot, so that it is lighter and less likely to crack. If desired,
trimming can give the pot a foot: a ridge of clay at the base to serve
as a design accent. Some pots can be trimmed during the throwing stage
and the mark of the cutting wire smoothed out with a rib or the thumb.
Most
often trimming or turning or tooling is done when the pots have dried
to the leather hard stage: still moist but dry enough to hold their
shape without distorting. If the pot becomes too dry, there is a danger
of cracking; if too soft it will sag. A pot that becomes too dry after
throwing can be restored to a leather hard stage by spraying with a
plant mister inside and out or momentarily soaking it in a bucket of
water. This should be done several times to reach the proper state. A
pot that has become to dry should be discarded as it often time would
take more time and effort to restore than it would to throw a new one!
In
trimming try to maintain the same fluid motion that you acquire in
throwing, so that the foot seems like a natural extension of the pot.
REMEMBER THAT THE INSIDE CURVE OF THE POT SHOULD RESEMBLE THE OUTSIDE
HORIZON OF THE POT. It is interesting to note that while Japanese
potters throw with the wheel turning clockwise, they trim their pots in a
counterclockwise motion. This makes the trimming marks blend into the
throwing rings without changing the surface texture.
Although the
height and contour of a foot depends on the overall design, the base
edge should have a slight bevel to make it less susceptible to chipping,
an outward taper of the foot will give the pot both an actual and a
visible stability. Especially wide shapes such as platters may need a
second foot to support the large expanse of clay and prevent sagging.
Tall pedestal type feet can be thrown separately, trimmed, and then
joined to a bowl or cup shape when the clay is leather hard. Hand built
feet can be applied to the trimmed bottom at the leather hard stage.
After
firing, sand the bottom of trimmed pots to remove any roughness and
prevent scratching of furniture. In some case it may be desirable to
glue a felt pad to the bottom of a pot