Dig my own clay

[JT101]

So I'm starting to look at storage vessels now. In particular clay storage pots for wine, which are traditionally made of terracotta.

But the question is, what type of clay to use to make the pots, and where to dig it up. I'm in South-East London, so in the area or Kent. So far, all the clay I've seen is sort of orange or blue.

Does anyone know of any deposits or where I should be looking, and what type of clay to search for?

Thanks

[berry]

HAve you worked with clay before? Digging up your own would require a fair bit of manual labour and processing it thats why i've only ever done it once and even then I just made a simply air dried thumb pot and didnt fire it. It was a lazy weekend

After that It would be test! test! test! Only way to know for sure what your clay is like, how it will handle, how it takes a glaze etc

IF you ever do get pots made you could experiment with pot 'refrigerators'.

[doofaloofa]

See if you can find a potter in the area

i know a potter and he has a great knowledge of the different types of clay and where to find them

a brick works may be of help, if there are any in the area

[Wheelhead]

http://consult.kent.gov.uk/portal/min-d ... 7615823406

[Wheelhead]

Do you know how to process the clay JT101? Its a lot of hard work. Valentine Clays are good in Stoke on Trent http://www.valentineclays.co.uk
I don't think it matters what colour the clay is, the important thing is to find out what temperature it needs to be fired at :)

[doofaloofa]

don't let hard work put you off

it's character forming or something

[Wheelhead]

Sorry, didn't mean to sound defeatist :) The orange clay is probably terracotta :) just make it into a slip by adding water, then sieve it to get rid of the worms stones and twigs, dry it out on a plaster slab till its plastic again, and then you can use it after you have wedged and kneaded it to get the air out.

[JT101]

I'm no stranger to hard graft so that won't be an issue. I like a challenge

Ok, I've dried out some large lumps of clay that I cut into small pieces. Some of the clay I have to say was blue, some was orange and some was brown.

I tried to get all clay, but there is definitely some sand mixed in there. When I make the slip, how do I separate the clay from the sand and possibly bits of soil which will surely fall through a sieve?

And how do I decide what temperature to fire it at, once i get it pure?

[dustydave]

I'm not sure if sand is that much of a problem.Too much clay content means that the pot or brick or thumb pot will warp slightly when you fire it. That is why they add sand to brick clay; to get a standardised shape, unfortunately that means that the bricks don't weather quite so well.

The diferent colours you have depend on the ferrous - ferric state of the iron content, ie the deeper down you go the less oxygen and the greater reduction of the iron content and so darker green/blue colours, the higher up, and away from the water table, the greater the oxygen content and so the iron oxidises and has a rusty red colour. This is called the redox potential, or in agriculture it is called gleyic clays, ie in badly drained clays blue/grey mottling of the iorn in the clay indicates that the soil is badly drained. I hope that this whittering helps.

[Wheelhead]

You will need to do a few test firings. Usually you can bisque fire at 1000 degrees centigrade. Most clays are still porous after firing at this temperature and you can paint a glaze onto them and fire them again to melt the glaze. Some clay, like terracotta is glost fired at around 1100 to 1200 degrees centigrade, but you will have to do some tests because clays will slump at different temperatures.

[Wheelhead]

Obviously, you will need a pottery kiln to fire the pots in....:)

[Skippy]

You can of course use a clamp kiln . It's an ancient technique I've seen tried at an EH event a few years ago. It's almost in effect a glorified bonfire , so difficult to control and there were a number of failures from what I can remember. This is an idea of how it works ,
http://www.butser.org.uk/iafimg5_hcc.html
If you ever get the chance to run into this guy he knows pretty much all there is to know about clay and pots and is a very amenable bloke to talk to , Jim the pot
http://www.trinitycourtpotteries.co.uk

[John Headstrong]

I have also been playing with clay recently. The clay has come from my local community garden where we had a digger in to prepare that land for the second pollytunnel. We have used it for a pizza oven and I have used some in the form of a slip for a sealant on a heater in the pollytunnel.

when it came to firing, if I was to fire anything, I thought 'sawdust packed oil drum' was the way.