Mike Stanfield on tue 14 mar 00
Hi everyone,
I am new to the group and kinda new to throwing. My question is about
clay weights.
Is there standards or generals for how high you want to throw? for
example to throw a 8" vase how much clay is needed?
thanks in advance,
mike
Earl Brunner on wed 15 mar 00
Difficult to say Mike, You've got the vertical measurement,
but what about diameter? To keep is simple, your pot should
have a consistent thickness
from top to bottom. Smaller pieces might not taper at all,
being the same thickness from top to bottom, Some larger
pieces and undercut pieces like bowls and rounder forms, may
need some extra thickness left at the time of throwing, but
have it mostly trimmed off later. Horizontal or nearly
horizontal wet clay needs more thickness to hold itself up.
Think about balance, your eye will take in a form and
automatically estimate what it should weigh before you even
pick it up. And your eye will also expect
the weight to be distributed a certain way in the pot. So
as you begin to pick it up, the closer the actual weight and
balance are to the visual,
the more satisfying. This holds true if the piece weighs too
much or too little. Some potters get into a "Let's make the
biggest thinnest pot I
can with this piece of clay. People are sometimes impressed
with this
but I believe it to be almost as much of a defect as a pot
that is out
of balance in weight or too heavy. I have almost dropped
pots that my
muscles expected to be a certain weight and they were
significantly
lighter. It was an uncomfortable surprise. I'm sure the
potter would
have wanted me to buy it if I had broken it.
Mike Stanfield wrote:
>
> ----------------------------Original message----------------------------
> Hi everyone,
> I am new to the group and kinda new to throwing. My question is about
> clay weights.
> Is there standards or generals for how high you want to throw? for
> example to throw a 8" vase how much clay is needed?
> thanks in advance,
> mike
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Peter T. Wang on wed 15 mar 00
hi mike,
yes i'd say there are rough estimates for max. height of a thrown cylinder
as a function of the mass of clay. but it depends on a few factors, e.g.,
density of clay, and more importantly, throwing technique.
i have heard in general a 12-inch cylinder can be thrown with 3 lbs. of
clay. 16 inches with 4 is pretty tough but it's possible. i've only
managed to do 20 with 5 once, i'm sure there are others who can do better,
but i have damn skinny arms.
of course this is all wet height/weight, and doesn't take into account
fired shrinkage. and besides, a cylinder makes for a boring vase after a
while. so shaping the form loses some height. how much you shape also
determines max. height.
in short then there are lots of factors: clay type, clay density,
throwing technique, shape of desired form, and fired shrinkage. the best
way to get a feel is by experience and through familiarity with the clay
and the form you want to explore.
-peter
On Tue, 14 Mar 2000, Mike Stanfield wrote:
> ----------------------------Original message----------------------------
> Hi everyone,
> I am new to the group and kinda new to throwing. My question is about
> clay weights.
> Is there standards or generals for how high you want to throw? for
> example to throw a 8" vase how much clay is needed?
> thanks in advance,
> mike
>
miriam on wed 15 mar 00
Mike-
A book that gives a very useful weights chart is Robin Hopper's Pottery
Form and Function.
Mike Stanfield wrote:
>
> ----------------------------Original message----------------------------
> Hi everyone,
> I am new to the group and kinda new to throwing. My question is about
> clay weights.
> Is there standards or generals for how high you want to throw? for
> example to throw a 8" vase how much clay is needed?
> thanks in advance,
> mike
Dannon Rhudy on wed 15 mar 00
At 02:07 PM 3/14/00 EST, you wrote:
>----------------------------Original message----------------------------
>Hi everyone,
>I am new to the group and kinda new to throwing. My question is about
>clay weights.
>Is there standards or generals for how high you want to throw? for
>example to throw a 8" vase how much clay is needed?
>thanks in advance,
>mike
>............................
There are likely several sources, but certainly in Cushing's Handbook
there is a page or two with common weights-to-pots listed. Very
helpful. Specifically regarding your question, it would be helpful
to know not only how HIGH your vase is, but how WIDE. Makes a
difference.
regards
Dannon Rhudy
potter@koyote.com
martin howard on thu 16 mar 00
Test your own facilities.
Here we have a 3 inch bore pugmill.
Each 10 cm from that bore weighs 1 kg. So each 4 cm is 400 gm. A convenient
plastic top of the clay container marks the sausages off in 4 cms. So there
is an easy guide for 400, 800, 1200, 1600, 2000 gm. weights.
I then found that the length in cms gave me roughly the height in inches for
a narrow vessel.
But for an 8 inch high vase, that formula tended to go astray and I need 10
cm, 1 kg.
A note of all your findings on the wall is a great help.
As time goes on, you find you can do with less, so amend the listing and the
formulae.
Martin Howard
Webb's Cottage Pottery
Woolpits Road
Great Saling
BRAINTREE
Essex CM7 5DZ
01371 850 423
martin@webbscottage.co.uk
www.webbscottage.co.uk Should be ready for 2000 :-) or 2001
Steve Dalton on thu 16 mar 00
Mike,
It varies on how thin/thick you want the piece. A good
starting guide to base further ideas is a book in the
Complete Potter series..."Throwing." I started with
the weights in there and since have adapted to suite my
needs. Either more or less clay. On the 8" vase, I would
use 2 1/2 lbs. This leaves me enough clay on the bottom to
trim an indented foot.
Steve Dalton
----------
> From: Mike Stanfield
> To: CLAYART@LSV.UKY.EDU
> Subject: throwing weights?
> Date: Tue, 14 Mar 2000 14:07:53 EST
>
>----------------------------Original message----------------------------
>Hi everyone,
>I am new to the group and kinda new to throwing. My question is about
>clay weights.
>Is there standards or generals for how high you want to throw? for
>example to throw a 8" vase how much clay is needed?
>thanks in advance,
>mike
Rob Sanders on thu 16 mar 00
I'll second that! I used to enjoy giving some of my high school students
what we called "the typewriter test". I had an old (heavy) manual
typewriter in a cupboard under the counter. I would ask a student to get it
out and put it on the nearby table for me. Then ask him to get a piece of
paper from a stack. [Why did he pick up the typewriter with both hands and
the paper with only one hand?] If he was still with me I would set out a
series of bowls--some too heavy, some too light, and some "just right".
(Where is Goldielocks now?) I would ask him to pick up each bowl and set it
down one at a time. Usually no explanation was necessary, and others
watching wanted to try it to see what it was all about. Needless to say,
the student's throwing usually improved immediately! Also requiring a 6"
cylinder, cut in half to show even wall/bottom thickness before proceeding
to next project was an important step. They hated doing that, but always
were glad they did it.
----- Original Message -----
From: Earl Brunner
To:
Sent: Wednesday, March 15, 2000 1:42 PM
Subject: Re: throwing weights?
> ----------------------------Original message----------------------------
> Difficult to say Mike, You've got the vertical measurement,
> but what about diameter? To keep is simple, your pot should
> have a consistent thickness
> from top to bottom. Smaller pieces might not taper at all,
> being the same thickness from top to bottom, Some larger
> pieces and undercut pieces like bowls and rounder forms, may
> need some extra thickness left at the time of throwing, but
> have it mostly trimmed off later. Horizontal or nearly
> horizontal wet clay needs more thickness to hold itself up.
> Think about balance, your eye will take in a form and
> automatically estimate what it should weigh before you even
> pick it up. And your eye will also expect
> the weight to be distributed a certain way in the pot. So
> as you begin to pick it up, the closer the actual weight and
> balance are to the visual,
> the more satisfying. This holds true if the piece weighs too
> much or too little. Some potters get into a "Let's make the
> biggest thinnest pot I
> can with this piece of clay. People are sometimes impressed
> with this
> but I believe it to be almost as much of a defect as a pot
> that is out
> of balance in weight or too heavy. I have almost dropped
> pots that my
> muscles expected to be a certain weight and they were
> significantly
> lighter. It was an uncomfortable surprise. I'm sure the
> potter would
> have wanted me to buy it if I had broken it.
>
> Mike Stanfield wrote:
> >
> > ----------------------------Original message----------------------------
> > Hi everyone,
> > I am new to the group and kinda new to throwing. My question is about
> > clay weights.
> > Is there standards or generals for how high you want to throw? for
> > example to throw a 8" vase how much clay is needed?
> > thanks in advance,
> > mike
>
> --
> Earl Brunner
> http://coyote.accessnv.com/bruec
> mailto:bruec@anv.net
Janet Kaiser on thu 16 mar 00
Sorry to say I have looked for the list everywhere, but cannot find it. As
far as I recall it was weights of clay and the corresponding PLANT POT size
for each one. According to my teacher, this was seemingly used as a "norm"
in production workshops up to World War II. The size of the plant pots was
the direct result of the weight of clay used and not vice versa.
I suppose it would still be valid for most potters? Certainly gives a
standard in a non-technical and easily remembered way. All you need to do is
find someone who throws/turns plant pots! That would probably mean visiting
a retirement home in the UK.
Janet Kaiser
The Chapel of Art, Criccieth LL52 0EA, GB-Wales
Home of The International Potters Path
TEL: (01766) 523570
WEB: http://www.the-coa.org.uk
EMAIL: postbox@the-coa.org.uk
Percy Toms on fri 17 mar 00
Janet Kaiser wrote
>Sorry to say I have looked for the list everywhere, but cannot find
it.
>As far as I recall it was weights of clay and the corresponding PLANT
POT
>size for each one. According to my teacher, this was seemingly used as
a
>"norm" in production workshops up to World War II. The size of the
plant
>pots was the direct result of the weight of clay used and not vice
versa.
------------------------------------------------------------------------
----------
~ Hi, Janet
This brings to mind watching Svend Bayer throw a big red
earthenware plant pot like he'd done by the hundred, journeyman
throwing at Brannam's of Barnstaple, England with that great Fremington
clay. Two pull-ups and it was done... the biggest, quickest pot us
student potters ever saw fresh-thrown.
Then he wired the bottom, put his arms around it (it was wide) and
lifted it off. No batt. He set it down on a board, gave a couple of
pokes to un-dent where he touched it. It stood straight and proud,
new-born, grinning at us. We gaped.
Point I'm getting to, is ... in production potteries of yore and even
today I can see how that list of standard weights could work to
streamline hand-production. Svend could have made that pot a little
lighter, I imagine (though to us, it was positively buoyant when
lifted) -but I suspect it would not then have been so manageably lifted
off the wheel, batt-less. The standard list weight was perhaps - I
speculate - the least amount of clay for the size that still allowed
the pot to be directly lifted from the wheelhead, sans batt and sans
buckling. That would save time in a production pottery, compared to
using batts.
Ned
Andrew Buck on fri 17 mar 00
Hi All,
This is the way I work also. I weigh out the clay and make a pot. Measure
the pot to see what the thrown size is and make a note in a log that I
keep by my wheel. After trimming, I mark the pot with the weight of clay
used to make it. Then, if someone wants a pot that matches something they
bought earlier, I have an idea of where to start. This also gives me a
place to start when making something of a different shape but similar
size. Something to remember, also, is that a cylinder of the same height
and wall thickness, but twice the diameter, will take roughly three times
as much clay (Pi times the diameter equals the circumference).
I also use this weight system as an aid to pricing my pots. Typically,
the more clay used to make a pot, the bigger the pot is. Bigger pots
require more time to make and glaze. They also take up more space in the
kiln. I find that the difference in the labor and associated costs of
making a pot work out roughly as a ratio (price per pound). My base price
ratio is currently at $6.00 per pound of clay used to make something on
the wheel. To the base price for a pot I will take a little off for
really easy forms and add some for harder forms. I take away a little on
the price for pots that come out less pretty than I like and add to the
price of the "shiners". Highly decorated items, of course, get priced much
higher than pots that are just dip glazed.
An example of my pricing method would be plates and platters. A 10 inch
dinner plate is a very simple form for me to throw and I usually dip glaze
them in a single glaze. Two plates will easily fit on my 12 by 24 inch
kiln shelves. As I start with three and a half pounds of clay for one of
these, the base price would be $21.00. Because I can throw one of these
relatively fast and do not spend a whole lot of time in glazing, I will
usually take a little off this base price for a plate that doesn't
particularly go with a set. A larger platter, while it doesn't take a
whole lot more time in the throwing, does take a special batt, as well as
extra care in drying, trimming and glazing. Also platters require special
treatment in the kiln because they do not fit on a standard shelf. All of
this, as well as any special decoration, adds to the base price. So a
fourteen pound platter, that is 21 inches in diameter when thrown (18
inches when fired), would go for much more than the $84.00 base price.
This method is not perfect, but, it is a good guide. Look at the pots
that you produce now and check the weight/price ratio. You might be
surprised at what you find. Remember, the materials are "dirt cheap" and
the labor is your major expense.
On Thu, 16 Mar 2000, Janet Kaiser wrote:
> ----------------------------Original message----------------------------
> Sorry to say I have looked for the list everywhere, but cannot find it. As
> far as I recall it was weights of clay and the corresponding PLANT POT size
> for each one. According to my teacher, this was seemingly used as a "norm"
> in production workshops up to World War II. The size of the plant pots was
> the direct result of the weight of clay used and not vice versa.
>
> I suppose it would still be valid for most potters? Certainly gives a
> standard in a non-technical and easily remembered way. All you need to do is
> find someone who throws/turns plant pots! That would probably mean visiting
> a retirement home in the UK.
>
> Janet Kaiser
> The Chapel of Art, Criccieth LL52 0EA, GB-Wales
> Home of The International Potters Path
> TEL: (01766) 523570
> WEB: http://www.the-coa.org.uk
> EMAIL: postbox@the-coa.org.uk
>
Andrew Buck on fri 17 mar 00
Hi again All,
Yesterday I had a minor brain burp. In what I feel was other wise an OK
post, I just lost it with this statement:
> Something to remember, also, is that a cylinder of the same height and
> wall thickness, but twice the diameter, will take roughly three
> times as much clay (Pi times the diameter equals the circumference).
I have no idea where that came from. Anyway, it's 3:30 in the morning and
I can't sleep thinking about all the fun some of you are going to have
telling everyone what a dork I am. So I got up and did some midnight
math. Here are the results that I ended up with. I hope I did a better
job this time.
If a cylinder with a diameter equal to its height, of uniform wall
thickness, is thrown, without a bottom, and one unit/weight of clay is
used, then, keeping the diameter and wall thickness the same, to double
the height of the cylinder twice the amount of clay would be required.
To double the diameter while keeping the height the same, twice the amount
of clay would also be required. Doubling both the height and diameter
would require four times the clay.
If a cylinder of a diameter equal to the inside height, with a bottom,
were thrown, then, to double the height the weight of clay would have to
be increased 1.8 times. To double the diameter while keeping the height
the same, the weight would need to be increased by 2.4 times. To double
the height and diameter both, the weight would increase by 4 times.
If you are throwing shapes that are more complicated than a straight
walled cylinder, use the above as a guide or get someone else to do the
math. Maybe I can get to sleep now. %*0 ZZZzzzzzz
Andy Buck
Raincreek Pottery
Port Orchard, Washington
David Hendley on sat 18 mar 00
Hi Janet,
In the States, the old-time potters threw in 'gallons'.
Their proficiency was judged by how many gallons they
could throw in a day. Crocks and jugs were also sold
'by the gallon'.
Today, volume-per-pound still makes more sense to me than
height-per-pound.
We had a woman thrower (unusual in those days) at the
near-by old-time pottery in the 1920's whose claim to fame
was a one-gallon pitcher from 5 pounds of clay. That's still
my standard of measurement for a really skilled thrower.
--
David Hendley
Maydelle, Texas
hendley@tyler.net
http://www.farmpots.com/
----- Original Message -----
From: Janet Kaiser
To:
Sent: Thursday, March 16, 2000 11:49 AM
Subject: Re: throwing weights?
| ----------------------------Original message----------------------------
| Sorry to say I have looked for the list everywhere, but cannot find it. As
| far as I recall it was weights of clay and the corresponding PLANT POT
size
| for each one. According to my teacher, this was seemingly used as a "norm"
| in production workshops up to World War II. The size of the plant pots was
| the direct result of the weight of clay used and not vice versa.
|
| I suppose it would still be valid for most potters? Certainly gives a
| standard in a non-technical and easily remembered way. All you need to do
is
| find someone who throws/turns plant pots! That would probably mean
visiting
| a retirement home in the UK.
|
| Janet Kaiser
| The Chapel of Art, Criccieth LL52 0EA, GB-Wales
| Home of The International Potters Path
| TEL: (01766) 523570
| WEB: http://www.the-coa.org.uk
| EMAIL: postbox@the-coa.org.uk
|
Stephen Mills on sun 19 mar 00
Going slightly sideways: at the old country pottery I used to spend time
at some years ago the throwers used to set up a lump of clay on the
wheel board in front of them, its weight was approximately 30 kilos
(64lbs). This was called a "cast", from this the potter took the
required number of "handfuls" (2lbs) to make up the "pieces" from which
the pot was made. The measure there was 2 "handfuls" to the "piece".
Pots (apart from "Long Toms" whose origin I never found out) were named
according to the number that could be made from a cast i.e a 48 equals
48 pots to the cast.
Steve Mills
Bath
UK
In message , Janet Kaiser
writes
>----------------------------Original message----------------------------
>Sorry to say I have looked for the list everywhere, but cannot find it. As
>far as I recall it was weights of clay and the corresponding PLANT POT size
>for each one. According to my teacher, this was seemingly used as a "norm"
>in production workshops up to World War II. The size of the plant pots was
>the direct result of the weight of clay used and not vice versa.
>
>I suppose it would still be valid for most potters? Certainly gives a
>standard in a non-technical and easily remembered way. All you need to do is
>find someone who throws/turns plant pots! That would probably mean visiting
>a retirement home in the UK.
>
>Janet Kaiser
>The Chapel of Art, Criccieth LL52 0EA, GB-Wales
>Home of The International Potters Path
>TEL: (01766) 523570
>WEB: http://www.the-coa.org.uk
>EMAIL: postbox@the-coa.org.uk
>
--
Steve Mills
Bath
UK
home e-mail: stevemills@mudslinger.demon.co.uk
work e-mail: stevemills@bathpotters.demon.co.uk
own website: http://www.mudslinger.demon.co.uk
BPS website: http://www.bathpotters.demon.co.uk
Tel: **44 (0)1225 311699
Fax: **44 (0)870 0526466
Janet Kaiser on sun 19 mar 00
Hi David!
Seems to me we are talking about the same thing! Plant pots of a certain
size were measured by height times width (which therefore) equals volume.
They were naturally the same shape because they had to stack and they had to
stack contain soil by volume too. I notice you say the pots, crocks and
pitchers were/are also thrown from pre-weighed clay, so it is the same
surely?
This UK production throwing was also applicable to other items of course. A
large cider jar would (for example) be described as a 28lb cider jar... That
was the clay it took to make a jar of a certain size and measured content.
The potter was interested in the amount of clay and the cider maker would be
interested in the volume it held. Both knew what the other was talking
about.... I think!!
I know I still have a problem when a recipe calls for a 1lb or 2lb loaf tin.
I can never remember what size that means -- poor metricated European that I
have become! But then in the US "weighing" for cooking remains volume based:
cups, spoons, etc. whereas we use weights in the UK. It is obviously one of
those big cultural differences you never think about.
David Pritchard at Glynllifon Pottery is the only one I know who still uses
weight as an indication of size. All other domestic ware potters I know use
volume.. i.e. a one pint jug or half pint mug. The amount of clay they use
does not seem to measured to any norm or "standard" any more. Each
individual potter uses the amount of clay they find they need for the job at
hand. It usually comes with practice and experience.
For the inexperienced production potter who originally posted the question,
I think the plant pot idea is still a good place to start. Kind of gives a
mental correlation between weight and volume/size. It also gets around the
question of height versus width as you rightly point out.
Hope you are enjoying a Texan springtime?
Janet Kaiser -- Where the mountain and road sides are ablaze with golden
yellow gorse and the thorn bushes a froth of dainty white blossom.
The Chapel of Art, Criccieth LL52 0EA, GB-Wales
Home of The International Potters Path
TEL: (01766) 523570
WEB: http://www.the-coa.org.uk
EMAIL: postbox@the-coa.org.uk
----- Original Message -----
> Hi Janet,
> In the States, the old-time potters threw in 'gallons'.
> Their proficiency was judged by how many gallons they
> could throw in a day. Crocks and jugs were also sold
> 'by the gallon'.
> Today, volume-per-pound still makes more sense to me than
> height-per-pound.
>
> We had a woman thrower (unusual in those days) at the
> near-by old-time pottery in the 1920's whose claim to fame
> was a one-gallon pitcher from 5 pounds of clay. That's still
> my standard of measurement for a really skilled thrower.
>
> --
> David Hendley
> Maydelle, Texas
> hendley@tyler.net
> http://www.farmpots.com/
>
>
> ----- Original Message -----
> From: Janet Kaiser
> To:
> Sent: Thursday, March 16, 2000 11:49 AM
> Subject: Re: throwing weights?
>
>
> | ----------------------------Original message----------------------------
> | Sorry to say I have looked for the list everywhere, but cannot find it.
As
> | far as I recall it was weights of clay and the corresponding PLANT POT
> size
> | for each one. According to my teacher, this was seemingly used as a
"norm"
> | in production workshops up to World War II. The size of the plant pots
was
> | the direct result of the weight of clay used and not vice versa.
> |
> | I suppose it would still be valid for most potters? Certainly gives a
> | standard in a non-technical and easily remembered way.
> |
> | Janet Kaiser
Jean Cochran on tue 21 mar 00
Dear Andrew,
You are the only other potter I have met who puts the thrown weight on
their pots. I thought I was just obsessive compulsive. It works for
me.
Thanks,
Jean Wadsworth Cochran
Fox Hollow Pottery
New Haven, Kentucky
Andrew Buck on wed 22 mar 00
Jean,
This post has very little to do with the weight of clay used to throw a
pot, but, the tread has lead me in this direction. Just chalk it up to
"The devil made me do it".
I also, on the bottoms of my pot, besides marking down the weight of clay
used to throw it, write my name, my pottery name, the town, the state, and
the full date. My fellow potters KNOW that I am a little obsessive
compulsive. You would not be able to tell it from the neatness of
the studio though. I've been a full time potter for ten years now and
have always put all that information on my pots. (except the weight, which
I only started putting on the pots a couple of years ago) It has not
really increased my sales much, and I didn't start doing it for that
reason, but, wherever my pots go, people will now where and when they were
made. Hopefully it will let people feel more of a connection with the
"made by hand" qualities if they can identify the hand that made it to a
greater extent. I feel a real connection with ancient pottery made by
unknown potters. I don't "need" to know much more about them than what
they say with their pottery. I would "like" to know more about them
though. As any of the pots we make have the chance to last long enough to
be considered "Ancient", some day, I figure it is my gift to the future.
Who knows, maybe some day some future Clayart list will be commenting on
the fact that "those potters way back when sure did use a lot of clay to
make a mug". "They say that they only got $10.00 for all that work...".
Andy Buck
Raincreek Pottery
Port Orchard, Washington
On Tue, 21 Mar 2000, Jean Cochran wrote:
> ----------------------------Original message----------------------------
> Dear Andrew,
>
> You are the only other potter I have met who puts the thrown weight on
> their pots. I thought I was just obsessive compulsive. It works for
> me.
>
> Thanks,
>
> Jean Wadsworth Cochran
> Fox Hollow Pottery
> New Haven, Kentucky
>
| |
|
