What Clay to Use

Hello Everyone,

I am currently teaching pottery workshops. I was wondering what everyones opinion on clay was. What are your opinions on local clay in comparion to commerical clay? We sure do have lots of clay around Atikokan!!!

Thanks

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Atikokan Arts
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Hi.

I'm kinda a newbie, but that also means that I have a fresh memory of clays during the learning process. I think the most important thing in a clay for beginners is ease of use. A plastic clay that is kind to the touch - without too big "bits" in it that will scratch the surface when you are just sponging off the finished product. Also, if you are teaching on the wheel - pleeeeese use a clay that does not absorb water too quickly and doesn't have too large abrassive bits in it. We newbies spend a long time trying to center - I nearly buffed all the skin off the side of my left hand when I used my teacher's preferred clay. Fine for her - she centers in a minute - I spent 10-15 and wasn't in center then either.

That's my input - look for qualities of the clay, rather than locations. You want your students to enjoy the learning process. They will meet enough challenges along their way - "lousy" clay shouldn't be one of them :-)

Marianne

Reply to
Bubbles

Not bad input. For throwing I think a good fine plastic terracotta is good. Seems to have more tooth than fine white clays. For hand building a white slab clay is good for domestic ware, but for sculpture and coiling something strong and grogged IMO :o)

Reply to
Xtra News

I am using a white clay that has very fine (I think 0.2 mm) grog, which means that it is so fine, that it doesn't act like sandpaper when I am on the wheel, but it is still great for hand-building also - and very plastic. I wanted to use only one type of clay, since I have a teeny workshop and little space for handling 2 separate clays in the recycling process. Also makes for easier storage and cleanup, etc.

Here's the spec for the stoneware clay, in German

Apollo Steinzeugton 1000 - 1300°C

Westerwälder Steinzeugton ( WM2502 ), sehr fein schamottiert

Hervorragender Drehton, sehr plastisch, gute Standfestigkeit, auch für sehr grosse Stücke. Einfach und gut im Trocknen. Guter Glasurträger. Raku möglich.

Technische Daten Rohbrand 960 - 1000°C Brennbereich 1000 - 1300°C Sintertemperatur 1220°C Brennfarbe weiss - hellcrème - hellgrau Trockenschwindung ca. 5% Brennschwindung bei 1000°C ca. 5 % Brennschwindung bei 1300°C ca. 5 % Beimischung ca. 25% Ton-Hardstoff, Körnung 0 -0.2 mm

Marianne

Reply to
Bubbles

I think you're on about clay gathered in it's natural state - from sea or lake shore. I have done this.

It was hell on earth to cut it out from the beach and transport it to a vehicle - our wheelbarrow sank into a rut as it is very heavy. It wasn't very much either. Hysterics combined with histrionics, got us there.

Then you have to dry it out, and smash it into powder form. This you sieve to remove stones, sand and debris. It is then slaked in a bucket of water. Then you have numerous pouring off the water, and removing the liquid clay, leaving as much sediment behind as you can. Then comes the placing on plaster batts and the wedging. Traditionally, you then dig a pit and store the wrapped clay in the pit for as long as you can. It becomes more plastic and useful with time.

Chinese Potters would do this for their Grandchildren, whilst they themselves, used the clay stored for them by their Grandparents.

I think it is a great 'one off' exercise from a learning point of view, but is so labour intensive, it does not become the cheap source you think it should be. On the other hand, you may find you have a marvellous clay. It is cheaper and less painful just to buy it ready pugged.

Mine I shall use for sculpture work, that does not get fired but makes excellent models for casting in ciment fondue.

Hope it helps. Roz

Reply to
Roz Lacey

I once dug a small amount of clay from the lot on which a friend was building a house and used it as a glaze for a housewarming gift pot. The glaze was brown and a bit gritty, but not bad. It probably would have been a clay at cone 04 but it was a glaze at cone 6, and I didn't need more than a couple buckets of the clay to start with.

Janet

Reply to
Janet Price

My experience exactly, with "garden clay" from our yard. I did test it at c/04 and it was a nice pink clay. The small amount of sand in it wasn't a problem since I am a hand-builder, but it also had plenty of lime specs that caused "lime pops" after firing. So, since the digging was a lot of work (and since the amount available from the garden was limited anyway), and since it had to be sieved pretty fine to get rid of the lime, I use it only as a glaze. Instead of a mediocre low-fire body, I get a nice c/6 glaze (about like Albany Slip?) that will go a lot farther for the effort it took.

Best regards,

Bob Masta dqatechATdaqartaDOTcom D A Q A R T A Data AcQuisition And Real-Time Analysis

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Bob Masta

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