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videos and arm pain

updated tue 13 nov 07


Digital Studio on thu 8 nov 07

I was actually just editing some throwing videos that I thought of
posting on Youtube... they're mainly for fun. I've been debating if I
should put them up, I don't want to have bad comments on them though. As
for Marek's videos, I have a lightning speed internet connection and
they load as soon as I click them. I like Jim and Tim's videos, and
pretty much any throwing video that gives good tips. Fong Choo's teapot
demonstration videos are very, very good. He's really interesting to
watch, how he thinks about the form and how he doesn't like to harass
the clay.
Something else that I saw when looking back through this huge thread
about videos was the right way to do physical things in ceramics. Last
Tuesday was our last day to throw in my ceramics class, so I wedged up
about 15 or so pounds of clay to make last minute bowls. It took me
about 30 minutes to wedge the whole thing, taking breaks every minute or
so. I'm not sure if the clay was too hard or the room was cold, but some
factor in my wedging gave me pain in my elbows similar to tennis elbow.
Centering the huge hump was a task in itself, and I used warm water
which I thought might warm it up a little and make it a tad softer, but
that didn't work. After my elbows started hurting, I tried not to slap
the clay which would have made it worse. I woke up the next morning with
a strained left wrist... and my elbows were fine. If the hardness of the
clay was my only problem, how could I have softened it? I'm fairly sure
our wedging setup is good, if you look back at the email I sent with
links to pictures, you can see our wedging table behind me in the ones
where I'm trimming. Help me save my elbows! :-)

Tim See wrote:
> Marek,
> you need to understand that when you post a response to a text like this or about a video what
> you say relates to the previous text. example
> bowl pics
> hi guys here are some bowl pics sarah
> re: bowl pics
> wow i have never seen such a sorry excuse for a
> pottery let alone a bowl. Tim
> re:bowl pics
> oh thanks mr god of pottery get a life Sarah
> re:bowl pics
> oh no i wasnt talking about your bowl i was talking about Kevin purplefart
> why on earth would you have thought i was
> talking about your bowl? Tim
> Do you see how that can be misunderstood. I dont like hurt students either. what would be nice if
> you gave us a link to the bad video/videos you are talking about and maybe have an intervention
> with the person that posted them. maybe draw an quarter them. or post a response on there video
> warning and giving an alternative. Tim See
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Kendra Bogert

Marek & Pauline Drzazga-Donaldson on thu 8 nov 07

Dear Kendra,

your RSI from a 15 lb of clay makes me think that the clay is certainly =
too stiff. But also 30 minutes is far too long. Kneading and wedging an =
amount of clay should not take longer than 3 - 4 minutes max. So you are =
doing it too long.
Table height for anyone, whether you are built like a gibbon (my trainee =
Ian is 6 foot 3 inches tall
but uses the same table height as me - short arse 5' 7", long torso =
short arms and legs), or ideal proportins, is judged by standing and =
facing the wedging table relaxed, and your fingers just brushing the =
Stance is vital also, keep the clay at a full arms length, so that your =
angle of attck is about 45 degrees, one leg in front of the other =
(interchangeable to suit) and rock your whole body using your body =
weight and not the strength in your arms, but from your shoulders. It =
should be a fluid movement, and when the clay starts to move towards you =
move it away again. You need only deal with a very small part of the =
clay at any one time, so a 25 lb lump of clay will equate to about 5 lb =
when you are kneading properly.
Throwing large amounts of clay demand that the clay be soft, and also =
when you are dealing with a large amount on the wheel, you need only =
consider about a fifth of the total weight. Also remember that the =
larger the piece of clay the greater the dynamics, so it is easier to =
throw a large piece that a small one, if you control the fear factor, =
keep the wheel going slow and haved the clay soft, then it should be =
easy peasy.

happy Potting Marek

Hand made Architectural Ceramics from No9 Studio UK
Fully Residential Pottery Courses and more at Mole Cottage =
"Tips and Time Travel from a Vernacular Potter" reviews on =
an irreverent point of view after 35 years in the game Marek =
Drzazga-Donaldson =20
Assemble a dragon finial at
Free Works and Mole Cottage DVD's and Video content on all the sites
Drzazga Video Promotions at Submit address for DVD

Michael Wendt on thu 8 nov 07

You might consider stack and slam wire wedging.
Thus method is low impact, easy on wrists and
hands and it allows you to change the moisture
content of clay easily.
a mass of clay (5, 10 or 15 LBS ) is selected that
is an even multiple of the desired weight for the
It is cut in half by a wire strung against the wall
at a 45 degree angle next to the wedging table.
The two pieces are stacked, then slammed on
first the one side and then the other to join
That piece is cut in half and the process is repeated
until the mass is uniform.
Once you get fast, it takes as little as one minute
to make almost any reasonable to lift size of
clay even in moisture.
Drying clay requires some clay that is too stiff
to add to clay that is too wet.
Moistening clay requires a spray bottle to
mist the joining faces prior to each joining until
the desired softness is reached.
10 doublings is over 1000 layers
20 doublings is over 1,000,000 layers
30 doublings is over 1,000,000,000 layers
from this it is clear why this works so well
and is much easier on the wrists and hands
than spiral wedging.
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501

Lee Love on thu 8 nov 07

On 11/8/07, Digital Studio wrote:
If the hardness of the
> clay was my only problem, how could I have softened it? I'm fairly sure

If you have a clean floor (don't want to raise dust) drop the bag
of clay on each of the six sided before wedging. Some clays will
soften with this.

If you need to make it softer, before you leave the studio,
soak a towel and wrap the clay up with it. Put the plastic bag over
the wrapped clay and close it. Should be softer the next day.

Lee in Minneapolis, Minnesota USA

"Men are born ignorant, not stupid. They are made stupid by
education." -- Bertrand Russell

Taylor Hendrix on thu 8 nov 07

My Gawd Kendra!

Too long, you're wedging that piece of clay way way too long. Of
course you know that now that every tom, dick, and harry on the list
has told you that. Don't you wish there were more toms and harrys on
the list to balance out all the ... never mind. How did you keep your
clay from crumbling into dust? hee haw.

For the love of Pete, get your clay soft, soft, soft. Lee and others
have repeatedly encouraged me to soften my clay. It solves all kinds
of problems with throwing. Of course it might cause other problems,
but you can deal with them easily as they come up. Your joints will
thank you.

The wire wedging method is fantastic for getting clay even in
moisture, but it will quickly kick your butt if the clay is too hard.
Better to just slab the clay with the wire, add water and bag it for a
time. Marek's vids are fantastic for seeing how to wire wedge, but man
does he use a bunch of clay! See this youtube vid for a more managable
amount of clay. That clay is SOFT, lady. Look at that jug go! I wire
wedge just exactly as he does now.

Any clay I have that won't spiral or wire wedge easily goes on the
hump molds for a real spanking. Thanks Russel. He's the man.

Rock on Kendra,

Taylor, in Rockport TX

On 11/8/07, Digital Studio wrote:
> Tuesday was our last day to throw in my ceramics class, so I wedged up
> about 15 or so pounds of clay to make last minute bowls. It took me
> about 30 minutes to wedge the whole thing, taking breaks every minute or
> so.

Ivor and Olive Lewis on fri 9 nov 07

Dear Michael Wendt,=20

10 doublings is over 1000 layers
20 doublings is over 1,000,000 layers
30 doublings is over 1,000,000,000 layers

An interesting piece of mathematics, illustrating the Power of Two. But =
at what point to those layers you are making become thinner than the =
clay crystals that comprise the clay ? And do the layers reduce in =
thickness if the clay is passed through rollers ?

Michael Wendt on sat 10 nov 07

The uniformity is in the moisture.
Slam wedging is not milling the clay.
Despite wedging on a wet table,
at 25 doublings, the clay seems
to begin to stiffen. I measured
the yield with my clay stiffness
tester and confirmed this.
I suggest that the clay is so
uniform and the electrostatic
charges are so evenly distributed
that it becomes perceptibly
stronger... no soft spots to initiate
What do you suggest as an explanation?
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501

Ivor and Olive Lewis on sun 11 nov 07

Dear Michael Wendt,=20

I have used the cut and slam system. Learned to do that at Sunderland =
College of Art back in the 1960's. I would confirm making similar =
observations, that after a period of time clay does stiffen as you =

But I also get a similar effect using spiral kneading. In fact, =
resistance to motion becomes quite remarkable. However, even though this =
firmer clay stands up well it remains easy to centre.

This seems to suggest there is a paradox at work. It is generally =
thought that the water works as a lubricant so a stiffening of the clay =
would suggest that water is being lost, not enough water to provide =
sufficient lubrication and the intervention of frictional forces as clay =
particles contact each other. Obvious pathways are adsorption into the =
wedging table or evaporation.=20

I would speculate that the effect we notice is the result of breaking =
down and refinement of Floc Structures. When a clay water mixture is =
newly formed by dewatering original slop it has a natural "Shortness" =
and will fracture due gravitational stress, indicating it is almost =
structureless. I have recorded large smooth shear surfaces similar in =
form to "Slickensides" . After being wedged and kneaded , then dried and =
etched it is possible to reveal flow structure and estimate the size of =
the flocks. Flocks tend to be small at the surface but are larger =
towards the interior.

Michael, you may recall my views on the Clay/Water relationship are =
somewhat heretical. The Electrostatic Charge distribution of a Kaolin =
crystal and the van der Waals forces of H/O\H molecules engenders a =
greater volumetric influence than we appreciate if we subscribe to the =
models of Lawrence and West. Their invocation of Zeta Potential =
(Electrokinetic Potential) would seem to be improbable since this factor =
describes potential differences across boundaries between a fluid in =
motion and a fluid layer fixed to a solid surface. It is an attractive =
model but it cannot account for the high volumetric relationship of =
water to solids in a plastic clay (contrast the views of Hamer and =

Best regards,