OK, I've been asked by many how in the world do you find clay in an area you've never been to? Well, that's simple. The USDA has sampled almost all of the soil in the United States, so either get a physical soil sample book for the county you want to visit, or find the county on the web from this site: http://websoilsurvey.nrcs.usda.gov/app/HomePage.htm and learn your way around.
Del Rio is nicely mapped. I was able to find an outcrop of soil/clay and using the net and my gps I found the area which was sampled in the report.
The area was baron, but in a different from the rest of the area.
I dug down and took a small amount of clay from about 6 inches from the surface. I tested the plasticity: Could I make a coil without it cracking too much, and could I smash it and do it again. I could.
So I dug about 40 pounds and placed it in my truck. And off I went back home. 8oo miles round trip.
And I started testing. How can I separate the undesirable from the clay? First I made a slurry out of the clay with water, then I sponged off the top (thinking about the Tera Sigillata: I knew clay would "ride" on water because of the small particle size and that the heavier, non clay particles would sink.) Then I ringed the sponge out on some plaster bats.
Clay. Del Rio 2335. (named after the FM road it was found near.)
I was able to throw a nice cylinder. This clay does not have the impurities I found in the Ellis County Brown clay I dug earlier so I am hoping when it's fired it will stay strong. It has a very plastic quality and I might be able to pull a handle from this clay.
My next post will document the cleaning process.
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