Chris R. on sun 29 apr 12
Hello All,=3D20
I am trying to make a clay that purposefully cracks and am hoping that
someone with more clay knowledge than myself can give me some ideas of ho=
=3D
w
to proceed! Or at least a good place to start...
The clay is not going to be fired. I need to fill a container with a 2" o=
=3D
r
so of clay slurry and allow it to crack as it dries....Like a dry lake be=
=3D
d.=3D20
I collected some clay just outside of Yellowstone several years ago and i=
=3D
t
does exactly what I need it to, but I need more....like a 1000 lbs plus. =
=3D
The
clay I collected in the wild is very dusty when dry, super silky when wet=
=3D
,
and cracks like crazy when it dries.=3D20
Any help would be appreciated!
Chris
Vince Pitelka on sun 29 apr 12
Chris R. wrote
"I am trying to make a clay that purposefully cracks and am hoping that
someone with more clay knowledge than myself can give me some ideas of how
to proceed! Or at least a good place to start... The clay is not going to b=
e
fired. I need to fill a container with a 2" or so of clay slurry and allow
it to crack as it dries....Like a dry lake bed."
Chris -
You just need high-shrinkage clays. Of the relatively cheap clays, ball
clays are the highest shrinkage, stoneware clays and earthenware clays a
little less. I am assuming that you are willing to buy clay for this, and
so, OM-4 is the ubiquitous ball clay carried by all clay suppliers. It wil=
l
give you serious "mudflat" cracking as it dries. You could do some
experiments adding sand and river silt, and you might get the results you
want using some free found materials.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net
http://iweb.tntech.edu/wpitelka/
Snail Scott on sun 29 apr 12
On Apr 29, 2012, at 3:55 PM, Chris R. wrote:
> I am trying to make a clay that purposefully cracks...
Add plenty of bentonite/montmorillonite. It'll crack!
-Snail
William & Susan Schran User on sun 29 apr 12
On 4/29/12 4:55 PM, "Chris R." wrote:
>Hello All,
>
>I am trying to make a clay that purposefully cracks and am hoping that
>someone with more clay knowledge than myself can give me some ideas of how
>to proceed! Or at least a good place to start...
>
>The clay is not going to be fired. I need to fill a container with a 2" or
>so of clay slurry and allow it to crack as it dries....Like a dry lake
>bed.
>
>I collected some clay just outside of Yellowstone several years ago and it
>does exactly what I need it to, but I need more....like a 1000 lbs plus.
>The
>clay I collected in the wild is very dusty when dry, super silky when wet,
>and cracks like crazy when it dries.
Might want to test just making some ball clay wet and see if it cracks on
drying.
Bill
--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com
>
Michael Wendt on sun 29 apr 12
Chris,
Check to see if Helmer Kaolin is available in your area.
It has 17.5% shrinkage from wet to dry and does jst
what you describe when made into a pure slip and dried
on any hard, non-shrinking substrate.
It is also available from me in bags or in bulk if
you live close enough to Lewiston, Idaho to pick
it up... or have it shipped.
Regardfs,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave
Lewiston, ID 83501
208 746 3724
youi wrote:
Hello All,
I am trying to make a clay that purposefully cracks and am
hoping that
someone with more clay knowledge than myself can give me
some ideas of how
to proceed! Or at least a good place to start...
The clay is not going to be fired. I need to fill a
container with a 2" or
so of clay slurry and allow it to crack as it dries....Like
a dry lake bed.
I collected some clay just outside of Yellowstone several
years ago and it
does exactly what I need it to, but I need more....like a
1000 lbs plus. The
clay I collected in the wild is very dusty when dry, super
silky when wet,
and cracks like crazy when it dries.
Any help would be appreciated!
Chris
John Britt on mon 30 apr 12
Try Ball clay or ball clay and bentonite.
Johnbrittpottery.com
Steve Mills on mon 30 apr 12
Hi Chris,
I think that ultimately going for that "natural" clay is still going to be =
y=3D
our best option.=3D20
At the start of my career I worked at an old country pottery which used ver=
y=3D
local clay. We added 30% sand to it which tamed it else it shrank so much =
i=3D
t almost self destructed.=3D20
I think it's going to be easier to dig than formulate!
Steve M
Steve Mills
Bath
UK
www.mudslinger.me.uk
Sent from my iPod
On 29 Apr 2012, at 21:55, "Chris R." wrote:
> Hello All,=3D20
>=3D20
> I am trying to make a clay that purposefully cracks and am hoping that
> someone with more clay knowledge than myself can give me some ideas of ho=
w=3D
> to proceed! Or at least a good place to start...
>=3D20
> The clay is not going to be fired. I need to fill a container with a 2" o=
r=3D
> so of clay slurry and allow it to crack as it dries....Like a dry lake be=
d=3D
.=3D20
>=3D20
> I collected some clay just outside of Yellowstone several years ago and i=
t=3D
> does exactly what I need it to, but I need more....like a 1000 lbs plus. =
T=3D
he
> clay I collected in the wild is very dusty when dry, super silky when wet=
,=3D
> and cracks like crazy when it dries.=3D20
>=3D20
> Any help would be appreciated!
>=3D20
> Chris
Vince Pitelka on mon 30 apr 12
Snail Scott wrote:
"Add plenty of bentonite/montmorillonite. It'll crack!"
Snail -
Actually, if you add plenty of bentonite it will crack too much. Bentonite
shrinks so much when it dries that it breaks up into chunks that look like
popcorn. You've probably seen that happen. It's a great demo to do for
students to demonstrate particle size and water layers. If you want to get
cracks like mudflats, then almost any normal clay would work better, and
ball clay would most likely work best.
- Vince
Vince Pitelka
Appalachian Center for Craft
Tennessee Tech University
vpitelka@dtccom.net
http://iweb.tntech.edu/wpitelka/
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