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cracks and linen

updated tue 15 feb 11

 

mel jacobson on sun 13 feb 11


i had a visitor from germany years back.
she was really a fine figurative sculptor.

she said....`plastic can be really hard on long term
sculpture projects. i use linen strips, wrapped around long
appendages, like arms etc as i work on them. it may take
me three days. if i wrap with plastic sheeting, the water
comes to the surface and just lays there. ruins things.`

i used this same theory with some potters in mata ortiz, mexico.
those three part wedding pots were cracking at the apex
of spout and two handles. (maybe fifty hours making one, and
crack. and of course three grand pesos lost.)

i `suggested` to them (you never tell fine potters
what to do, even if you know it is wrong.) to turn the pot over on a grid
of scrap wood
and cover the entire pot with cotton tee shirts. spout down.
it worked. some of those pots were like 28 inches across.
lots of shrinkage tension. i did get an email from a trader that
said `tell the big gringo to come on back to mata ortiz any time
he wishes...he knows his stuff.` i was glad i was right...they
are really fine potters. i just could not bite my tongue any longer,
as i knew what was causing the problem.

the natural fiber kept the pot from drying too fast.
just slows it. yet the pot breaths.
that is why i punch holes in my plastic sheet tent.
don't trap the moisture like a rain forest. the water
just drips back on the pots. you want a natural, slow
drying. the tighter your clay body, the slower you have
to dry. porcelain being the most difficult...my grog filled
sand filled body goes dry like a bansheee. few cracks,
ever.

our big damp closet in japan had a vent out the top to the
outside. not tight.
we had big plaster batts on the floor, and we dumped water
on them. but, the room was a slow drying room, not a storage
of wet pots room. they had to be leather for the next day.
far too many folks just cover too tightly. and, that can be as
bad as leaving the pots out all night. pots are ready when they
are ready. make sure you know how to help them along.
you may have to trim those 12 bowls at midnight.
mel
from: minnetonka, mn
website: http://www.visi.com/~melpots/
clayart link: http://www.visi.com/~melpots/clayart.html
new book: http://www.21stcenturykilns.com
alternate: melpots7575@gmail.com

Kathy Forer on sun 13 feb 11


On Feb 13, 2011, at 1:26 PM, mel jacobson wrote:

> the natural fiber kept the pot from drying too fast.
> just slows it. yet the pot breaths.

I'm quite fond of super-cloths. They're also great for absorbing =3D
unexpected flooding. http://www.GoodWillToo.com/browse.cfm/4,3327.html =3D
has them, aka shammy cloths. Though linen is better with delicate work, =3D
shammys hold more water, less on the surface, and seem better at =3D
resisting mold.

You can also use toothpicks or other support to raise the cloth above =3D
your work to create a tent. I wrap them in plastic after cloth. A dark =3D
plastic cover seems to transmit less daylight heat to the piece.=3D20

My teacher at the Art Students League, Jos=3DE9 de Creeft, used to =3D
compliment us on the way we wrapped our clay studies. The wrap was =3D
better form than what was inside. We got really into wrapping them after =
=3D
that!


Kathy Forer

Snail Scott on mon 14 feb 11


On Feb 13, 2011, at 12:26 PM, mel jacobson wrote:
> she said....`plastic can be really hard on long term
> sculpture projects. i use linen strips, wrapped around long
> appendages, like arms etc as i work on them. it may take
> me three days. if i wrap with plastic sheeting, the water
> comes to the surface and just lays there. ruins things...


This is especially prevalent when you get a cold
snap., when the condensation on the inside upper
regions of the plastic are even worse.

I don't use linen, though. (If I could afford linen, I
wouldn't use it in the studio.) I like cotton sweatshirt
fabric. It is cheap, holds a lot of moisture so it does
a good job of containing the condensation, and can
be heavily wetted without dripping if a stint of clay
rehydration is needed. It can mildew if left for a long
time (I've had projects that stalled out, and I kept
them wet for up to six months before I figured out
the solution.) Synthetics don't mildew, but they don't
hold the moisture nearly as well. The knit fabric
conforms well to the curvature of complex pieces
without pulling or biting into soft clay; woven cloth
is less accommodating.

When I just need to wrap something overnight, I
simply drape a cloth over the work before putting
the plastic on. If I need to rehydrate an over-stiffened
piece, I wet the cloth first, then tuck it closely around
the form so that there is maximum contact between
clay and cloth. I do this without as much moisture if
I am setting something aside for a prolonged break.
For this, I just pull off the plastic and spray the cloth
every few days before re-wrapping. To slow-dry
something, I wrap it in dry cloth, then the plastic.
The cloth absorbs humidity and helps equalize the
moisture levels inside the bag, preventing skinny
or projecting bits from drying first. Every day, I pull
out the cloth and put in a fresh dry one while the
now-dampened cloth from the previous day dries
out for the next day's swap.

For faster drying, just the cloth without plastic is
a big help, as it allows for some evaporation, but
blocks drafts and evens out the humidity under it.
For this, I find a loose wrap works best. A paper
tent will also serve.

This is seldom needed for pottery, but for large
sculpture, it's very handy. Even with smaller work,
though, I often put a cotton rag on top inside the
plastic to catch condensation.

-Snail

Nancy Spinella on mon 14 feb 11


I know what you mean about linen!

I like the plain old cotton floursack towels. When they get too holey or
stained for the kitchen, into the studio they go. :)

--Nancy

On Mon, Feb 14, 2011 at 12:29 PM, Snail Scott wr=
ote:

> On Feb 13, 2011, at 12:26 PM, mel jacobson wrote:
> > she said....`plastic can be really hard on long term
> > sculpture projects. i use linen strips, wrapped around long
> > appendages, like arms etc as i work on them. it may take
> > me three days. if i wrap with plastic sheeting, the water
> > comes to the surface and just lays there. ruins things...
>
>
> This is especially prevalent when you get a cold
> snap., when the condensation on the inside upper
> regions of the plastic are even worse.
>
> I don't use linen, though. (If I could afford linen, I
> wouldn't use it in the studio.) I like cotton sweatshirt
> fabric. It is cheap, holds a lot of moisture so it does
> a good job of containing the condensation, and can
> be heavily wetted without dripping if a stint of clay
> rehydration is needed. It can mildew if left for a long
> time (I've had projects that stalled out, and I kept
> them wet for up to six months before I figured out
> the solution.) Synthetics don't mildew, but they don't
> hold the moisture nearly as well. The knit fabric
> conforms well to the curvature of complex pieces
> without pulling or biting into soft clay; woven cloth
> is less accommodating.
>
> When I just need to wrap something overnight, I
> simply drape a cloth over the work before putting
> the plastic on. If I need to rehydrate an over-stiffened
> piece, I wet the cloth first, then tuck it closely around
> the form so that there is maximum contact between
> clay and cloth. I do this without as much moisture if
> I am setting something aside for a prolonged break.
> For this, I just pull off the plastic and spray the cloth
> every few days before re-wrapping. To slow-dry
> something, I wrap it in dry cloth, then the plastic.
> The cloth absorbs humidity and helps equalize the
> moisture levels inside the bag, preventing skinny
> or projecting bits from drying first. Every day, I pull
> out the cloth and put in a fresh dry one while the
> now-dampened cloth from the previous day dries
> out for the next day's swap.
>
> For faster drying, just the cloth without plastic is
> a big help, as it allows for some evaporation, but
> blocks drafts and evens out the humidity under it.
> For this, I find a loose wrap works best. A paper
> tent will also serve.
>
> This is seldom needed for pottery, but for large
> sculpture, it's very handy. Even with smaller work,
> though, I often put a cotton rag on top inside the
> plastic to catch condensation.
>
> -Snail
>