Talbott on wed 28 may 97
What are some common production methods used to make dinner plates, using
^9/10 stoneware or porcelain... I know that plates can be hand-thrown but
with much difficulty obviously or slab-built using molds to form the slab
over... but what about the other methods such a jiggering, ram-pressing,
etc.. Could some one briefly explain these methods and expense to get the
equipment needed to carry out those methods of production...
Slip-casting, ram-pressing, etc.. does not have that "original piece"
appeal, at least to me, but I know that a well know pottery in Edgecomb,
Maine uses all of the above methods of production. A relatively small
percentage of their work is actually hand-thrown.. However they are
consider to be the largest "Art Pottery" in the US and there sales are in
$ millions annually... They devote more time to glaze perfection, and for
them that was a smart move.. Lesson Learned.. to make "big money" you have
got to have time efficient production methods.... Flame ON!!!
1ST ANNUAL CLAYARTERS' GALLERY - NAPLES, MAINE (Summer 1997)
http://fmc.utm.edu/~dmcbeth/cag/naples.htm
Celia & Marshall Talbott, Pottery By Celia, Route 114, P O Box 4116,
Naples, Maine 04055-4116,(207)693-6100 voice and fax,(call first)
WBS Live Chat Room, Sat Nites 10 PM EDT, Private Room: Clayarters
David Hendley on thu 29 may 97
At 09:42 AM 5/28/97 EDT, you wrote:
>----------------------------Original message----------------------------
I know that plates can be hand-thrown but
>with much difficulty obviously or slab-built using molds to form the slab
>over...
I have to disagree with the term
"with much difficulty". A good, experienced potter can make plates at a
pretty good clip. If he adds a "bottom jig" {on an arm, similar to jigger
arm) to his wheel he can be even faster. If he has a good pug mill so
minimum wedging is required, faster still.
David Hendley
Maydelle, Texas
Marni Turkel on sat 31 may 97
I have spent hundreds of hours and thousands of dollars learning about
production techniques of dinner plates and am happy to pass on some
information. For those who believe that production potters along with
'weekend grandma hobbiest' should be scorned, just hit the page down
button.
Casting is good from the stand point of relatively little equipment for
start up. Casting molds are the most easy to understand of all the
production methods I have worked with and most within reach of a novice
mold maker. A casting table can be made for $50. A pump is nice ($250-300),
but not strictly necessary. You can buy slip or mix it with a jiffy mixer
for 50lb batches, more than that and you would probable want a 50 gallon
mixer after awhile. A viscometer (under $20) will save you much grief. If
you want a footed plate, you need a two piece mold unless you are willing
to accept a depression on the eating surface where the foot ring is. For
vitreous clay, I find that 8" finished diameter is the largest I can do
without the center sagging and touching the shelf. If you don't mind a flat
bottom, a one piece mold works well, but you need to be careful to avoid
pouring marks.
Jiggering is a forming techinque that uses soft clay, usually suitable for
throwing, with a mold that is centered in a chuck on wheel. A template
fixed on a rocker arm comes down and forms one side of the piece while the
other side is formed by the mold. For moderate production levels, a good
electric wheel can be converted for jiggering. The rocker arm can be made
by a competent metal worker (I was quoted $300-400 for a straight forward
jiggering arm, before I ran into the wacko machinist who finally made one
that also works for turning plaster). Several companies make them
commercially. Don't buy a Shimpo: it is poorly conceived and badly made
toy. I don't have experience with any other brands. The molds for jiggering
are difficult to make because they are turned and have to be dead on center
to work well. Templates are easily made from 1/8" aluminum with a jig saw
and a file. It is a great production method for round dinner plates if you
have a moderate production to warrant the investment in equipment. After
the first 100 or so, I found nothing appealing about throwing dinner
plates. Jiggering is quicker, more uniform, and much easier on the wrist
than throwing.
I had only one experience with Ram pressing. And that happened to be in a
quest to answer the question about dinner plates. The hydraulic press is a
large, loud, and to my mind unaesthetic but impressive piece of equipment.
A two piece mold held in two metal rings is fitted into the press. Plastic
clay is put in the mold and then the press slams the two parts together
with somewhere between 1 and 4 tons of pressure. The plaster mold has
tubing running through it for compressed air. An air jet is sent through
the mold on the bottom, releasing the piece. The bottom mold is dropped
down leaving the piece still stuck to the top half. A board is put just
felow the piece and air is run through the upper mold, blowing the piece
onto the board. More clay is put onto the mold and the process is repeated
with mesmerizing rapidity. It isn't hard to find people willing to do
pressing for you, because the equipment is so expensive that anyone who has
a press is usually looking for ways to keep it operating so it can pay for
itself. The price of the mold and the die (I did not not know how to make
molds at the time) was somewhere between $400 and $500. The company I dealt
with wanted to 'run the mold out': once the mold was in place they wanted
to go until the mold wore out--about 1000 pieces. I didn't. So I paid a set
up fee and only did 50 or so at a time for a few times. I was not satisfied
with the quality. The air forced one edge of the plate to come free first
and to a potter's eye, everything looked like it had had an accident. There
was an appallingly high rate of cracking from the sides in, probably from
too high a tonnage on the press for the clay I was using. Perhaps they were
learning about the limits of the pressing process, I didn't want to pay any
more for their education.
I have no experience with dry pressing, so I can't comment on that.
Marni Turkel
Stony Point Ceramic Design
Santa Rosa, California
>What are some common production methods used to make dinner plates, using
>^9/10 stoneware or porcelain... I know that plates can be hand-thrown but
>with much difficulty obviously or slab-built using molds to form the slab
>over... but what about the other methods such a jiggering, ram-pressing,
>etc.. Could some one briefly explain these methods and expense to get the
>equipment needed to carry out those methods of production...
>Slip-casting, ram-pressing, etc.. does not have that "original piece"
>appeal, at least to me, but I know that a well know pottery in Edgecomb,
>Maine uses all of the above methods of production. A relatively small
>percentage of their work is actually hand-thrown.. However they are
>consider to be the largest "Art Pottery" in the US and there sales are in
>$ millions annually... They devote more time to glaze perfection, and
>forthem >that was a smart move.. Lesson Learned.. to make "big money" you
>have
>got to have time efficient production methods.... Flame ON!!!
>Celia & Marshall Talbott, Pottery By Celia
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