iandol on sun 18 aug 02
Dear Lee Love,
You ask...."Isn't this how they all throw in New Zealand, Australia and =
South Africa? ;^)..."
Absolutely my friend, absolutely.
Was doing something like this today. I throw down rather than pull =
upwards. Because clay is incompressible, or almost so, the clay extrudes =
upwards. Exploits the physical and mechanical properties of our plastic =
earth. Best way to make tall pots. Methodology known to some Orientals a =
thousand years or so ago. Now a lost skill.
Best regards,
Ivor
Ruth Ballou on mon 19 aug 02
Craig,
I have to assure you that Ivor is not joking in the least..... Throwing
down is a great tool to gain some extra height on both cylinders and
bowls.... without counting against your three pulls..... It's kind of a
freebie. Another way to think of it is that the clay is propelled downward
with some force, hits the wheelhead and rebounds back up because it has no
where else to go! And to make it really work well you must make and
maintain an undercut on the outside at the base of the wall for a cylinder
or at the base of the foot on a bowl. Otherwise, the clay molecules move
downward and decide to stay there with the rest of their buddies. In
regular throwing, having an undercut enables you to get under the base of
the pot a bit and throw the entire wall, making for a lively pot. Clay and
metal or plastic have a terrific affinity for each other. Overcoming this
attraction is difficult. Hence, bottom heavy cylinders with extra clay at
the base of the inside wall and bowls with inner feet. An undercut breaks
the attraction. Frequently, on a pull, some clay escapes downward due to
gravity. If there is an undercut, the clay that moves downward can collect
in the void on the outside of the pot and easily be removed with a 45 tool
prior to the next pull. A straight cut on the outside with a tool will not
have the same effect. Without the undercut the clay collects both on the
inside and outside, increasing the attraction between clay and metal, and
making it harder with each subsequent pull to throw the entire wall to
create a lively unified pot. So many pots end up being two pots..... one
part thrown, one part trimmed to do what was not properly thrown in the
first place.......The trick is unifying throwing and trimming so that the
second is an extension of the first......not something to repair poor
throwing. Whoops...... I've gone a bit afield from downward throwing......
Ruth Ballou
Silver Spring, MD
> Ivor, that's pretty good...even believable, though I'm more than
>slightly skeptical. I'll try throwing down the pot to "extrude" a taller
>form and see how it works meself. I've thrown down the pot before to stiffen
>and stretch the walls, but this one is new to me. I suspect that there is
>more than a bit of jest or sarcasm in the post, eh? May have something to do
>throwing things "down under", being upside down on the "bottom" (ha-ha) of
>the world, whirlpools going bass akwards and all that other good stuff down
>there.
>Craig Dunn Clark
>619 East 11 1/2 st
>Houston, Texas 77008
>(713)861-2083
>mudman@hal-pc.org
>
>----- Original Message -----
>From: "iandol"
>To:
>Sent: Sunday, August 18, 2002 1:56 AM
>Subject: : Re: throwing upside-down
>
>
>Dear Lee Love,
>
>You ask...."Isn't this how they all throw in New Zealand, Australia and
>South Africa? ;^)..."
>
>Absolutely my friend, absolutely.
>
>Was doing something like this today. I throw down rather than pull upwards.
>Because clay is incompressible, or almost so, the clay extrudes upwards.
>Exploits the physical and mechanical properties of our plastic earth. Best
>way to make tall pots. Methodology known to some Orientals a thousand years
>or so ago. Now a lost skill.
>
>Best regards,
>
>Ivor
>
>____________________________________________________________________________
>__
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
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>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at
>melpots@pclink.com.
Craig Clark on mon 19 aug 02
Ivor, that's pretty good...even believable, though I'm more than
slightly skeptical. I'll try throwing down the pot to "extrude" a taller
form and see how it works meself. I've thrown down the pot before to stiffen
and stretch the walls, but this one is new to me. I suspect that there is
more than a bit of jest or sarcasm in the post, eh? May have something to do
throwing things "down under", being upside down on the "bottom" (ha-ha) of
the world, whirlpools going bass akwards and all that other good stuff down
there.
Craig Dunn Clark
619 East 11 1/2 st
Houston, Texas 77008
(713)861-2083
mudman@hal-pc.org
----- Original Message -----
From: "iandol"
To:
Sent: Sunday, August 18, 2002 1:56 AM
Subject: : Re: throwing upside-down
Dear Lee Love,
You ask...."Isn't this how they all throw in New Zealand, Australia and
South Africa? ;^)..."
Absolutely my friend, absolutely.
Was doing something like this today. I throw down rather than pull upwards.
Because clay is incompressible, or almost so, the clay extrudes upwards.
Exploits the physical and mechanical properties of our plastic earth. Best
way to make tall pots. Methodology known to some Orientals a thousand years
or so ago. Now a lost skill.
Best regards,
Ivor
____________________________________________________________________________
__
Send postings to clayart@lsv.ceramics.org
You may look at the archives for the list or change your subscription
settings from http://www.ceramics.org/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots@pclink.com.
iandol on tue 20 aug 02
No jest. No sarcasm. Genuine process. Artisans who were preparing =
porcelain blanks for jiggering porcelain work did it in England. Saw it =
in a film about Worcester ware, or was it Crown Derby about thirty years =
ago. Information can be found if you search for it.
Best regards,
Ivor.
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