Natural clay deposit

[SchwarzenSchafe]

I'm just getting into sculpture, and finding that buying clay in a store is expensive. Last weekend I was on a river trip (saskatchewan river) and found a nice clay deposit beside the river. It seems pretty strong and has a nice consistency when wet. It's a dark grey. I think because it dried as one enormous piece there are stress cracks all through it. What's the best way to use it? Dry it out completely, grind it to a powder, then add water as I need it? Any advice related to using natural clay deposits for sculpture is appreciated. I hope it works well, I have 100lbs and for another 2 hours of driving and 2 hours of work I could fill a pickup truck bed with it.

[Arrow]

I wish you luck. I have thought about doing this too. I don't know the physical make up of the natural clay your digging up, but exercise caution with powdered clay bodies. Wear respirator.

[SchwarzenSchafe]

Thanks, I do a lot of autobody work so I have plenty of safety equipment.

[grayem]

The times I have seen people do this, they had to add ball clay or fire clay into it.
You would have to do a few experiments with it to find out what temperature it can handle, that may not be worth your rime after digging it up, dragging it around etc.

[GaryR52]

I seem to recall, from a book on clay I read a while back, that, if you're going to use clay you've quarried yourself, you'll want to remove any organic matter from it and that the way to do it is just as you've described, i.e., dry it, powder it, but then, to remove any organic debris (grass, other plant material, rocks, etc.), you need to sift it with a fine wire mesh screen to screen out the debris. Once that's done, you've got clay flour. Just add water.

Gary

[SchwarzenSchafe]

I don't know if it's necessary for me to fire it... I want to take molds off it with silicone. I figure afterwards I could even re-use the clay, but I'm new at this. It's already pretty clean, I got the deep stuff so it looks pure, no debris. It was a little moist because the river was recently so high, so I've just dried a chunk tonight to test out.

Any links on working with clay? I can't seem to find much with google.

[GaryR52]

Well, in that case, you won't need to sift it for organic debris. Just dry, powder and reconstitute with water so you've got a plastic clay again. You could reuse it, too, by simply grinding it up again. Cheaper than buying a supply of Roma Plastilina, I guess.

Here's what I was able to find just Googling:

http://va.essortment.com/clayworkingwit_rrfk.htm

http://artsedge.kennedy-center.org/content/2202/2202_dollsculpture_workingclay.pdf

http://www.sculptor.org/Books/ClayTerracotta.htm

http://www.artshow.com/resources/ceramics.html

Not exactly what you're looking for, I know. It's pretty tough to find anything that isn't related to polymer clay!



Gary

[SchwarzenSchafe]

Yeah, that was my problem, sorting through all the polymer clay info to find the stuff I want... Heres some of the more interesting things I've found following the links you've given and through more searching:

http://www.studiopotter.org/articles/art0019.htm
http://www.claytimes.com/claybscs.htm#anchor509923

[fritchie]

Schwarzen - I've only known one person who collected natural clay, and I don't think she ever used it. This was a somewhat older lady who had taken quite a few private classes with experienced sculptors, and she got this from a local riverbed. She gave me some years ago, and I may have played with it, but was advised by more experienced workers not to spend time with it.

It actually is a mix of colors - yellowish, purplish, and reddish. The stream was mostly gravel, and I suspect the clay came downstream from a range of deposits. This lady also fired small clay sculptures, and I think that’s what she may have had in mind.

When I first brought this material up wth the other sculptors, they said things like “fat” clay, and so on. It seems some clay simply will crumble into bits as it dries, and what you want in sculpting is a clay that will become quite hard as it nearly dries, but that will not shed dust or crumble. You should be able to see what happens as you work with it. Just be forewarned to be careful with your time.

[SchwarzenSchafe]

Thanks for the reply.

Well, I made a quick test with it, it's workable when wet and I can bend it without it cracking. I rolled a piece the size/shape of my pinky finger and it's fairly dry right now (as dry as 24 hours gets clay, not completely). I snapped it in half and it took a fair bit of pressure. It sands beatifully. The grain reminds me of soapstone but strength is weaker. It doesn't seem like it'll hold fine detail like store-bought clay. Maybe not ideal but how much money would YOU spend on materials to model a life-size elephant? I'm just futzing around and learning the basics of sculpture and mold making so for me, right now, I think it's perfect.

I'm going to do another test side-by-side comparison with store-bought clay.

[Ameenah]

This may help.
http://www.mudfire.com/index.htm
I'm thinking of checking this out myself.
Ameenah

[fritchie]

Thanks for the reply.

Well, I made a quick test with it, it's workable when wet and I can bend it without it cracking. I rolled a piece the size/shape of my pinky finger and it's fairly dry right now (as dry as 24 hours gets clay, not completely). I snapped it in half and it took a fair bit of pressure. It sands beatifully. The grain reminds me of soapstone but strength is weaker. It doesn't seem like it'll hold fine detail like store-bought clay. Maybe not ideal but how much money would YOU spend on materials to model a life-size elephant? I'm just futzing around and learning the basics of sculpture and mold making so for me, right now, I think it's perfect.

I'm going to do another test side-by-side comparison with store-bought clay.

Good to take a practical approach. Keep us up to date, as I'm sure we all will learn from this.

[SchwarzenSchafe]

I've had a chance to play around with it. I pulverized it on a tray with a hammer and added water till it was a thin liquid and all the chunks were dissolved. After letting it sit the water can be poured off the top and it can be laid on a tray to dry. Theres only the odd grain of sand in it so I don't think I need to filter it, but I could strain the soup through a cloth if I wanted I'm sure. Once given the chance to fully dry it's strong... I haven't done extensive tests because it's more than strong enough for my needs but it seems easily as strong as the store-bought stuff I have.

In short, it's absolutely perfect and I'm very happy with it! No idea how it'll fire though, I'm not interested in clay as a final medium so I don't really care how it fires.

[SchwarzenSchafe]

I was just playing around some more comparing it to the stuff from the store...

It holds detail very well, nice and malleable doesn't crack when it bends. When dry it seems like the store-bought stuff is finer grained or it has something else in it. The river stuff carves like a weaker soapstone, but the store-bought stuff doesn't seem as dry, like I'm carving off chunks that are still pliable and they bend even though it's fully dry. The river stuff doesn't do that, when it's dry it doesn't bend at all, only breaks.

[fritchie]

Thanks for this run-down. It's been quite a while since I used "store-bought" clay, but the material I had also was too stiff to move at all when it nearly was dry, and it broke or crumbled if you tried too hard. In fact, a major concern when using this water-based clay in sculpture classes was keeping the clay a good working consistency.
People would wrap the sculpture in a carefully dampened, not wet, cloth, and then wrap that in plastic, tied tightly. That would hold the piece for 2 - 4 days until the next class (or even longer if necessary). A mist spraying bottle was used on the clay periodically during class.

[Ameenah]

Water based clay seems like allot of trouble ,unless your using it for pottery. Am I missing something? Why bother? Oil based clay lasts forever and you can reuse the clay after casting. Well I guess if you are thinking about cost and being able to fire your work at will. Then I can understand. :)
Ameenah

[sculptor]

reminds me of the tale of Camille Claudel----on a rainsoaked paris night---down in a pit under a paris street dug by the sewer repair guys-----rainsoaked dress and hair looked like a mad woman hacking out clay and carrying off baskets of the stuff---police failed to see the artist behind the facade of madness and hauled her off----shadows of things to come?

ok-----dig your own---great idea-
--i have built lifesized pieces with waterclay(ISIS and Angelicus)
great stuff----works easier than oil clay and if you let it dry a bit to leather hard it strengthens the armature and later holds detail well and can be easily altered with slip------when done, I throw the stuff inna bucket and cover with water----then into an old washtub with a hole in the bottom (with a hose connected) I get it real soft and kneed it through my fingers and pick and float out the gathered debris then pass it through a screen to get out the smaller nonfloating debris then onto a tray to partially dry...when it's near the hard end of being workable, I roll and pound and punch and beat it up until it's plyable, then wrap in freezer rap(kind of heavy plastic rap) and store in a closed cabinet till needed-----
double edged sword----water clay is easier to work and easier to control the hardness while working, but it needs to be covered with a moist sheet and plastic while resting between workings-----rumor has it that some of Rodin's fractured pieces got that way from clay neglect, and/or freezing----so oil clay is a lot more forgiving of neglect------seems wierd to save on clay and cast in silicon rubber which ain't cheap.
When he returned to Florence, Cellini practiced with the local clay for sculpting, and building the ceramic shell over the wax for his Perseus and Medusa and bust of the Duke----in the life he said that clay is different everywhere he worked, and needs to be studied carefully.

[GaryR52]

---shadows of things to come?

Maybe, if you're mining for clay in a cemetery. ;)

Gary

[Louie Arce]

Sorry I didnt read all the posts. So if I repeat an answer forgive me. When I was in school i would just look in the lockers at the end of the semester in the art dept. for students old projects that air dried /and would allso find old solid rock hard bags of clay. With a little time and water just dump all the air dried clay into a five gallon bucket add some water /cover it...and presto in some time you will have new clay. The cermaics instructor did this at the end of every semester and he never purchased clay. If your not in school just drop into the local junior college at the end of the semester ...find the lockers before they clean them out and you will have a consistant supply. I have not purchased clay in about ten years. Just think of it as recycling unwanted horrible projects.

[rootdoctor]

I have just been delivered a load of dirt with huge chunks of the most beautiful bue clay. Some of the chunks are deep cobalt blue and others are a more medium and azure and sky blue. It is definately several shades of blue. (no green) It has incredible adhesion. Can anyone tell me how to refine this...to get the black dirt off of it so I can use it for sculpting? The black dirt is not really mixed into the chunks...its more on the outer surface. I read somewhere about mixing with water and then after a day the dirt and sand will all be on top and pour off. Can anyone advise or lead me to directions for refining natural found clay? Thank you. Maggie

[melholms]

I'm new at working with clay and am really enjoying it. I've just started digging natural clay and working with it and I was wonder where you guys find the different colors. Also, if any one has any tips for me on what type of area is most beneficial to dig, I'd greatly appreciate any advice I can get.

Melissa

[wideman]

I too have been trying to refine my own clay (I just built a kick-wheel and just want to use it, I'm not worried about firing yet).
I got my clay from a couple feet underground when I was digging a hole for a fence post, and was at a lose as to how to get it clean enough to use. After a little poking around I found this site, http://www.rain.org/global-garden/soil-types-and-testing.htm which, although it doesn't say anything about pottery, has a diagram showing how soil separates, and clay, having the smallest (lightest) particles of the ingredients, settles last and is the top layer. So what I did was completely saturate the clumps I had and break them up in the water. After a vigorous stirring and then a few hours of settling time, the water on top was clear, so I first poured off the excess water, than poured the next layer (presumably clay) into a separate container. The thickest and darkest layer underneath was silty mud, and I stopped before that went out with the clay. All that remains is to dry my clay. I poured it through a screen to get any debris out (alot went out with the water before though) and then I left half of it out, hoping a day of sun would evaporate the water, it didn't do much. I poured half of it through and old shirt yesterday, and that seems to have done it. It still needs to dry more, but I am fairly certain it will be 100% clean smooth clay when it does. I'm just making this process up as I go, but it should work, I'll let you know if the results are disastrous.

[wideman]

Well, I made a bowl with it, and it worked great. What is the best way to make clay into a powder? I might want to try that route next time...
As far as where to find it, there's stream beds of course. It's my impression though that clay is found there because it settles out of the water, and the stream cuts down low enough to expose clay already in the bank. The clay itself is eroded feldspar, which could be anywhere. My first dig was in a low area where water drained through, and the topsoil was very thick. My best luck was on slightly tilted ground above the drainage route, that is where the topsoil is thinner and the clay is easier to reach.

[Landseer]

Water based clay seems like allot of trouble ,unless your using it for pottery. Am I missing something? Why bother? Oil based clay lasts forever and you can reuse the clay after casting. I for one don't like the texture oil clay has when tooled, the little sharp edges and balls that wind up developing in details as you work it, it's also sticky on the hands and usually smells like an old gas station bay or oil refinery.
It also gets contaminated with bits of plaster, lacquer if you spray it on for molding, stray hairs, dirt etc.

I buy 1000# of boxed clay from Georgies in Portland. It's cheap, perfect for large pieces and cheap enough to throw away. Shipped via truck on a pallet they got a good rate for me. I figured it cost about 50 cents a pound with the freight for the 1000#

CC512 • Three-Finger Jack
TFJ's network of grog and sand form an internal structure for a incredibly plastic clay without excessive coarseness. Great for slabs and handbuilding, it's even throwable. Work large: this clay can take it. Shrinks 8% in firing.

500# is $170
1000# is $310
2000# is $560

As far as found clay as our colleague discovered, I would research a bit on this before digging it. I notice that clay is used to seal things or cover to prevent gasses or water penetration- like abandoned landfill, chemicals, sewer lines and other industrial sites.

I know here there is a layer of clay above, and one below a very old 12" diameter clay storm drain that is 6 feet underground, it was obviously PLACED there though it looks natural- were the pipe not there one could assume they were natual deposits, but these two layers are a uniform 6" thick and about 3 feet apart. The line dates to at least the 1880's and was long abandoned and sealed up before my house was built in 1930 as several sections were removed to put the basement in.

I'd check to make sure this clay isn't some kind of industrial waste clay/slurry that was dumped a few decades ago after being used for who knows what, or it could have been some kind of old industrial clay that was used for fill and backfilled with dirt above it.

So much illegal and careless dumping and other practices going on for so long, I'd be suspicious just happening upon a deposit of something that would bring money to a finder- wondering why others hadn't removed it earlier.
Sometimes theres a reason WHY.

When you can buy a half a ton of good clay, pre-packaged and ready to use for $310, I can't see spending 4 hours of driving and many hours digging and hauling, screening cleaning and conditioning it is going to really save any money.

[wideman]

Good point. I was assuming they would be looking in undeveloped areas, I definitely wouldn't poke around construction clay.
That said, there is alot of satisfaction (beyond economics) to be had in digging up your own clay. I would much rather have local ingredients than ship anything. I may just be lucky, but it's here, it's good, it's fun to get and clean, and 100 feet away is pretty local. Even if a car ride is involved, I think it's worth it for the feeling of shaping something directly out of the earth and into your art.

[Landseer]

Good point. I was assuming they would be looking in undeveloped areas, ARE there any, any more? those areas would be perfect dumping spots for late night dumpers...

I've read that New Jersey had clay found around the turn of the century that was perfect for architectural sculptures while the clay in nearby Staten Island was garbage and inferior, that shows clay quality can vary big just a few miles apart.
Wonder if the same clay from NJ is still available, most was a grey color and a lot was a buff yellow.

Another firm in the Chicago area got their clay in the 1930's as a side product of a large coal mine, turned out that about 4 feet below the coal seam there was a marvelous layer of clay that was just perfect for them, once the mine stripped the overlaying coal they only had to take off 4 more feet of dirt to reach the clay, so it was a win-win situation. They had the clay shipped in by rail cars, sometimes in the winter the clay was frozen in the cars and they had to use dynamite to remove it!

One time the guy used too much and it destroyed the car and a nearby shop building.
It would make sense coal and clay would be near each other.

[wideman]

ARE there any, any more? those areas would be perfect dumping spots for late night dumpers...

Well, I guess I'm lucky to be farming and in an area with clay under the topsoil. And no "dumpers"

I got alot more nartural clay! I used a skid steer to pile up the topsoil and the collected a couple hundred pounds of clay (with a little soil and roots) and dumped it in tanks and tubs of water. The clumps wouldn't break at first, but I left for a few days and when I came back everything stirred into the water smoothly. It's settling now.

Does anyone know what happens if it is... say, 10% soil? I know I can get pure, but I'm curious.... It's a beautiful dark color.

[sculptor]

clay mine story:

pleasant prairie Wisconsin
they stored dynamite in an abandoned tunnel
then
one fine day
it ignited around 6:am
cracked windows and scared people out of bed 10 miles away

I think the clay was used to make bricks