Bobbie Fenton on thu 14 feb 08
Not sure were you are - I'm down on the gulf coast. Clay we pull out of the river banks is useable straight from the river and fires just fine. Look for blue or yellow clay - works well. The red stuff has too much sand and cracks. The white streaks that may be found in blue (sometimes blue green gray) are fine and don't seem to bother anything. There is a pure blue clay if you can get to it here that has a heavy silver content. You can mix ball clay or grog with any of it to suite your texture. There are several artists down here that use this clay. I rather like just opening a box myself and haven't messed with any of the natural clay just because it's a real pain to haul it by bucket out of the creek and up to the truck, ect., ect. I'd rather spend that time making pots!
Bobbie Fenton
Mississippi Stone Pottery
Justin M Smith wrote: I recently started teaching for clovis adult school in fresno ca. (centeral
valley), one of my students have expressed an interest in finding and
digging her own clay. Now while most of us enjoy 25# of mud in a bag in
relation to the great deal of work of mining clay, I dont want to discurage
the student. Does anyone have any suggestions on one goes about finding
usable clay in nature? Any help or information regarding mining natual
clays would be helpful.
Justin Smith
Clovis Adult School.
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Marcia Selsor on thu 14 feb 08
Dried river beds are a good place to start. Also road cuts in the
sides of hills.
I use to teach a class where we mined our own clay in Montana.
We mixed a slurry, screened it and dried it in plaster vats to a
workable consistency.
Be sure to test with tests in bowls or a catch basin just in case the
clay is very low fire.
Marcia Selsor
http://marciaselsor.com
Justin M Smith on thu 14 feb 08
I recently started teaching for clovis adult school in fresno ca. (centeral
valley), one of my students have expressed an interest in finding and
digging her own clay. Now while most of us enjoy 25# of mud in a bag in
relation to the great deal of work of mining clay, I dont want to discurage
the student. Does anyone have any suggestions on one goes about finding
usable clay in nature? Any help or information regarding mining natual
clays would be helpful.
Justin Smith
Clovis Adult School.
James and Sherron Bowen on thu 14 feb 08
There should be glaze making materials as well in your area of California.
JB
----- Original Message -----
From: "Justin M Smith"
To:
Sent: Thursday, February 14, 2008 1:38 AM
Subject: mining local clay
Duff bogen on fri 15 feb 08
JSmith
I'd say don't re-invent the wheel- look around at whose used clay in your area before.
I googled fresno brick manufacturers and got to this link-
http://calbricks.netfirms.com/index.html His intro =
"This is about California bricks, California brickmakers, and their history. My initial interest in bricks began when I found a salmon firebrick with the brand name "Carnegie" stamped into its face. This brick was made at the Carnegie brick works in San Joaquin County, California,"
Also look for "Fireclay" and "Coal"
http://calbricks.netfirms.com/brick.livermorefbco.html
Yes digging clay doesn't make economic sense but niether does making pots... and digging clay is certainly a good way to learn about clay.
Justin M Smith wrote:
I recently started teaching for clovis adult school in fresno ca. (centeral
valley), one of my students have expressed an interest in finding and
digging her own clay. Now while most of us enjoy 25# of mud in a bag in
relation to the great deal of work of mining clay, I dont want to discurage
the student. Does anyone have any suggestions on one goes about finding
usable clay in nature? Any help or information regarding mining natual
clays would be helpful.
Justin Smith
Clovis Adult School.
______________________________________________________________________________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here: http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpots2@visi.com
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William Lucius on fri 15 feb 08
I applaud your student for wanting to connect with the clay at its =
source. And it is easy if you break it down for him/her. Sounds like a =
wonderful excuse for field trips!
First of all, pull out a bit of you commercial clay and inspect its =
physical characteristics. When wet, it is plastic. That is, its =
physical structure is such that water lubricates tiny little plates =
which allows them to slip paste each other - the water acts as the =
lubricant. When it is dry, it has a characteristic soapy feel, not as =
much as soapstone but in the same order. Take a bite of it, and you =
will note that in addition to being gritty due to the added aplastics =
that it has a characteristic mouth feel. Sort of hard to describe but =
think of Kaopectate.
Then go out into the landscape and find stuff that is comparable. It =
helps immensely to have a strong geology background, but in lieu of that =
begin by driving along the long, narrow trenches that your Department of =
Transportation has carved for your convenience (they think of them as =
roads) and look clay outcrops in the road cuts. Of course do not =
attempt this on the L.A. or any other freeway - stick to the back roads =
where there is a shoulder. All you need is a trowel or small shovel and =
a collection bucket or sack. It is a good idea to bring along a =
notebook to record location, appearance, etc. Remind them that this is =
schoolwork!
Finding the clay is actually only the beginning. It has to be =
processed. Excellent clay only needs enough water to make a pliable =
mass. Otherwise add an excessive amount of water and stir vigorously, =
letting the coarse fraction settle to the bottom. Discard that and then =
let the bucket stand overnight and begin pouring off the water until you =
can move it to a plaster bat, which will dry it out to a workable =
consistency. Unless the clay is self-tempered (archaeology talk) you =
will need to add an aplastic such as molochite to reduce shrinkage and =
minimize heat shock. Stay away from quartz sand! Then you need to make =
test tiles of some sort to determine if it useable.
If the student has not given up by this time, it is time for test =
firing. If it bisques without cracking, exploding or otherwise =
undergoing spontaneous destruction, dip the test tile into a low fire =
glaze (unless they are white refractory clays, it is unlikely that they =
will tolerate temperatures above cone 4) and fire. I would recommend =
only oxidation firing since the iron content in most native clays is =
high enough to cause bloating or even melting under reduction firing. =20
Just a few thoughts that might help you along the way. Remember to tell =
you student that the journey promises to be interesting. And it would =
probably be helpful to remember that during most of the last 11,000 =
years that folks have been making pottery that there were no 25 lb. bags =
of pugged commercial clay with a cone 10 stamps on the box.
William A. Lucius, Board President
Institute for Archaeological Ceramic Research (IACR)
845 Hartford Drive
Boulder, CO 80305
iacr@msn.com
www.instituteforceramicarchaeology.orgaeology.org/>
www.leuppkilnconference.org
http://groups.msn.com/LeuppKilnConferenceConference>
Gail Fullerton on fri 15 feb 08
The=
central valley in California is covered with clay, it is everywhere, gen=
erally the valley floor is either clay or sand and mostly it's clay. =
; It is the bane of architects, engineers and builders who want to preven=
t their buildings from sinking into the ooze in the winter, and rising ab=
ove ground in the summer when the clay dries and shrinks, or maybe one co=
rner of the building rises while the opposite corner sinks. Finding=
clay is no problem, finding clay good for pot making might be a little h=
arder. The first thing to learn is what we in the building world ca=
ll the "spit test," crumble a little promising dirt between yo=
ur fingers into the palm of your hand, spit into it and see if it be=
comes like clay. Can you roll it into a ball which doesn't cru=
mble, can you flatten the ball into a pancake, and then can you roll it i=
nto a thin coil and wrap it around your finger? If so, you have a c=
andidate for further testing if you want to make pots. If that is y=
our building site, it's time to mutter your favorite profanities and begi=
n the process of finding the best way to deal with the stuff.
Che=
ck with any local structural engineer or architect, the US dept of agricu=
lture, the geology faculty at Fresno State and/or Fresno City, the Fresno=
County building dept. The dirt that is the worst for construction =
or growing crops will most likely be the best for your purposes.
Gail Fullerton, former c=
enral valley architect, now Fairbanks Alaska architect (sometim=
es) and potter (most of the time) - 50 below a few days ago, 30 abov=
e yesterday, zero and snowing today. A person can't ever get bored =
with the weather here.
------ Original Message ------
Received: 01:26 PM AKST, 02/14/2008
From: Justin M Smith <clovismud@GMAIL.COM>
To: CLAYART@LSV.CERAMICS.ORG
Subject: mining local clay
I recently started teaching for clovis adult school in fresno ca.=
(centeral
valley), one of my students have expressed an interest in finding=
and
digging her own clay. Now while most of us enjoy 25# of mud in a =
bag in
relation to the great deal of work of mining clay, I dont want to=
discurage
the student. Does anyone have any suggestions on one goes about f=
inding
usable clay in nature? Any help or information regarding mining n=
atual
clays would be helpful.
Justin Smith
Clovis Adult School.
_________________________________________________________________=
_____________
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change =
your
subscription settings or unsubscribe/leave the list here: http://=
www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at melpo=
ts2@visi.com
=
Ivor and Olive Lewis on fri 15 feb 08
Dear Justin M Smith,=20
I would suggest that your student purchase a Post Hole Auger, size 4 =
inch dia. This can be used to cut through top soil into the under strata =
of prospective sediments. Drilling down two to three feet will yield =
enough for evaluation before getting the back hoe out.
caveats.
Always fill the holes that are made to prevent an injury to another =
person or an animal.
Always ask permission of the land holder.
Always carry a valid prospecting licence.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Paul Haigh on fri 15 feb 08
Try this link for an overview. http://www.kitcornellpottery.com/teaching/clay.html
Paul Haigh
Londonderry, NH
Mike on fri 15 feb 08
Bobbie,
Granted it's a ton of work, but the stuff you dig for yourself is nearly
always far more interesting to work with, and makes for interesting
work. You'll be doing yourself a huge favor if you use collected clay.
One way to make it less onorous is to do it with friends, and divide the
spoils. Digging clay is a great excuse to get together with friends and
drink beer, especially if they pot too!
Mike
in Taku, Japan
www.karatsupots.com
karatsupots.etsy.com
karatsupots.blogspot.com
Bobbie Fenton ????????:
> I rather like just opening a box myself and haven't messed with any of the natural clay just because it's a real pain to haul it by bucket out of the creek and up to the truck, ect., ect. I'd rather spend that time making pots!
>
>
>
Michael Wendt on sat 16 feb 08
I disagree with those who say digging
and processing your own clay makes
no sense. If you have the room to
spread and process clay without
bothering anyone or creating an
eyesore, it's very practical. Here's how:
Road cuts slough each year and road
crews go out with a loader and truck
to remove the material from the ditch.
After you determine the clay is to your
liking, find out who runs the crew.
If need be, "bribe" them with real promises
of pots made from the ditch clay.
They have to dump the clay somewhere,
why not on your land (if you have room).
The dumped clay can be processed a little
at a time without much work by any of
several methods that are well explained in
existing books.
We dry grind but is you have water available,
washing the pile with a sprinkler will effortlessly
remove and carry the clay to a collection tray
made of black plastic. Rain showers will do
the same thing. If the tray is large and flat,
it will dry quickly, allowing more clay to be
washed into it. This is then your base body
material to which you add amendments
like ball clay, feldspar, talc and silica...
It can be any scale that fits your needs.
Hydraulic mining is how Grolleg Kaolin
is mined.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501
U.S.A.
208-746-3724
wendtpot@lewiston.com
http://www.wendtpottery.com
http://UniquePorcelainDesigns.com
Carole Fox on sat 16 feb 08
My potter pal Maggie gets hers for free from the local sand and gravel pit.
I'll bet she compensates the owner with a few of her wonderful pots here and
there.
I went with her once...fun, fun, fun! Clay in all colors! I got some black
clay that fired to a light buff color. The owner was such a nice guy!
Hey- it doesn't hurt to ask...
Carole Fox
Silver Fox Pottery
Elkton, MD
silverfoxpottery@comcast.net
Fredrick Paget on sat 16 feb 08
This valley where I live is floored with a beautiful clay. I call it
Mill Valley Cream. Unfortunatly the valley floor is 100 percent built
out but there is a rebuilding going on where old houses are torn down
and new bigger houses built on the lots. The older houses here like
mine were built in the 1920's .
I keep my eyes open and when ever I see a tear down I look for clay
when they start digging.
There was a gooder last summer when they tore one down up the street
from here and proceeded to dig a huge basement hole (or was it an
indoor swimming pool??).
There was a huge front end ditch digger machine that had a reach of
about 50 feet and at the bottom of the hole the clay was beautiful.
It looks like orange earthenware at cone 04 but I have fired some to
as high as cone 8 oxidation and it goes gray and looks like
stoneware.
The owner said take all you want as it was going to the dump anyway
and he had to pay to dump it.
Fred Paget
--
Twin Dragon Studio
Mill Valley, CA, USA
Robert on sat 16 feb 08
There is clay nearly everywhere on the planet. Our most utilized
elements, as potters, also happen to be some of the most abundant on the
planet.
It is another question how to find them and how to use them
appropriately. Most common, earthenware clays can be used as glazes or
glaze components at stoneware temperatures. As a clay body, earthenware
is ideally suited for a number of traditional wares in which the
porosity is advantageous to the utility. Flower pots, water
jugs/coolers and cooking pots come to mind. Easy to find.
Finding a local stoneware body, which I favor, can be a little more
difficult. USGS and state geology or bureau of mines publications can
be very useful. They are commonly available at university libraries and
sometimes community colleges with decent, or formerly decent, geology
programs. There is really very little land in this country that hasn't
been analyzed for the mineral resources. Fortunately for potters there
are many known deposits that fall beneath the category of being
commercially exploitable. I think geologist might be in Mel's list, "a
potter is..." Good to have some basic understanding. I liked the brick
manufacturer suggestion too and have sometimes availed myself of their
knowledge of the local clays. Any local excavation work. Even
historical production can be a good pointer. I think most of the
California fireclays come from a bit further north in the foothills of
the Sierras but it wouldn't surprise me if there were deposits of the
"non-commercial" variety closer to Fresno. I think the foothills north
north east would be your best bet. Hit the books.
In the field the rope/snake test gives a rough plasticity gauge, it's
usually obvious to a potter but sometimes clay with a high percentage of
very fine silica can fool you without the snake test.. I like the tooth
test myself for a clearer sense of particle size, get some strange looks
eating clay sometimes. Some areas you need to watch for lime
impurities. Soluble salts. I take samples of most clays I encounter. I
think I learned the standard tests from Rhodes' "Clay and Glazes..."
There are also some good suggestions on firing tests in the archives.
For clay bodies I prefer slip blunging. It gives a more plastic clay
with less aging and is relatively dust free. A five gallon bucket and a
drill mixer are more than adequate for small batches. Dry the clay
thoroughly. Slake the clay with excess water. Mix to a very wet slip.
Let settle. Strain through window screen. Another option at this stage
is how much of the coarse fraction you put back in the clay. It will
settle to the bottom and can be removed or included according to how you
pour it off. I usually leave the dregs myself. I like 2 x 6 frames
with 1/4" hardware cloth for drying racks. Roughly 10"x18" is a nice
size, not too heavy to handle. Line them with canvas or any fine thread
fabric (old sheets) and pour in the slip. Stack multiples with spacers.
Have fun,
Robert
Bill Merrill on sat 16 feb 08
Michael,
Processing your own materials can make sense. If you are a potter that
has specific needs, that industry doesn't cover, then exploring for
those materials can make a difference in your work. It depends of
course where you live. I go home to Wyoming several times a year.
During the summer months I hammer mill a beautiful feldspar. It can
vary , but I like to use=20
a more transparent spar so I kook for that in the raw spar. I also have
a site I dig an Albany like slip, that is black/green with titanium
flecks in it. I had it analyzed by Bondar clegg company. It didn't
cost much and it was fun to see what was actually in it. The slip was
high in calcium as the clay surrounded ancient oyster beds. Yep, there
was an inland sea that covered much of Wyoming. The are fossil part of
oysters in that clay.
Daniel Rhodes was a young potter/ teacher in '41. He was a craft
director in the Hart Mountain Relocation camp between Cody and Powell
Wyoming. He found a beautiful clay there. It is a warm toasty color and
be used right from the ground. I have a letter he wrote describing the
clay, with a map of the site. I use a little of that clay as something
I want to do on occasion. =20
Mining some of these materials is hard work. I find that it just makes
me feel better to do some physical labor. I am getting my left knee
replaced on Tuesday and will still do work in Wyoming during the summer.
I will have both knees replaced and recommend it to any
one with knee problems. =20
I have this saying. "Life is too short to use crappy materials". Be
Machiavellian, do and use what you have to do to get the job done!!
Keep making pots, the best one are yet to be made.
Bill
=20
-----Original Message-----
From: Clayart [mailto:CLAYART@LSV.CERAMICS.ORG] On Behalf Of Michael
Wendt
Sent: Saturday, February 16, 2008 8:47 AM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: mining local clay
I disagree with those who say digging
and processing your own clay makes
no sense. If you have the room to
spread and process clay without
bothering anyone or creating an
eyesore, it's very practical. Here's how:
Road cuts slough each year and road
crews go out with a loader and truck
to remove the material from the ditch.
After you determine the clay is to your
liking, find out who runs the crew.
If need be, "bribe" them with real promises
of pots made from the ditch clay.
They have to dump the clay somewhere,
why not on your land (if you have room).
The dumped clay can be processed a little
at a time without much work by any of
several methods that are well explained in
existing books.
We dry grind but is you have water available,
washing the pile with a sprinkler will effortlessly
remove and carry the clay to a collection tray
made of black plastic. Rain showers will do
the same thing. If the tray is large and flat,
it will dry quickly, allowing more clay to be
washed into it. This is then your base body
material to which you add amendments
like ball clay, feldspar, talc and silica...
It can be any scale that fits your needs.
Hydraulic mining is how Grolleg Kaolin
is mined.
Regards,
Michael Wendt
Wendt Pottery
2729 Clearwater Ave.
Lewiston, Id 83501
U.S.A.
208-746-3724
wendtpot@lewiston.com
http://www.wendtpottery.com
http://UniquePorcelainDesigns.com
________________________________________________________________________
______
Clayart members may send postings to: clayart@lsv.ceramics.org
You may look at the archives for the list, post messages, change your
subscription settings or unsubscribe/leave the list here:
http://www.acers.org/cic/clayart/
Moderator of the list is Mel Jacobson who may be reached at
melpots2@visi.com
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