Does anyone at DMS know anything about digging or finding and using local clay for pottery?
Sue has. There was a man at Northlake that had also, The clay varies
across the area The clay from east of Dallas and from the Grand Prairie ares
vould be more alike than Dallas clay
Thanks, Cairenn, but was it any good?
It shrunk LOT What Sue dug in her yard would have made a nice slip, It has to be adgusted, Talke to her
She s better with clay chemistry than I am
Local clay is a random event. Be prepared to do science. How much does it shrink? What other things are in the clay? These affect fired color, what you can make with it, and firing temperature. It is an art form with LOTS of work.
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There used to be a major clay works (stoneware) in Denton County in the 1800s because of some clay deposits there. The deposit is usually referenced as Eagle Ford (or Form). The USGS website lists it as Eagle Ford. There might be maps if you dig hard enough.
There are some scattered articles referencing historical Denton county stoneware, but it takes some digging and google-fu. I found a good article in the past on either the lewisville or denton county government site one time when looking for something. I lean towards maybe lewisville since the Denton county historical society doesn’t appear to have online articles.
Some of those articles, once you find them, might have enough clues to track down actual areas and much like rock hunting, maybe if you find a potential place, you could get permission to dig a little.
Acme brick still digs in Denton County.
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I’ve never had an interest in mixing my own clay. To much work. I have talked with several potters that dig up thier own clay. It has to be strained a several times to get the rocks and organic materials out. Vinegar is sometimes added when mixing it up. They used clay from the same place so fires at the same temp every batch.
You have to fire several test batches to find out what the vetrification temp is. Commercial clay may have several additives but, I don’t think there are any additives “have to” put in dug up clay, like I said I’ve heard of just vinger, YouTube has videos, please watch several to get different points of view.
I’ll be in Ga next weekend and plan to visit with several potters there. I’ll try to ask more questions about clay bodies.
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My boys and I played a little in our backyard a few years ago.
Not scientific at all and I knew it wouldn’t be the quality of professionally-made clay/slip - it was fun and it worked 
http://halfpasteight.com/blog/playing-in-the-mud/
http://halfpasteight.com/blog/caution-slip-hazard/
http://halfpasteight.com/blog/all-fired-up/
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Jchon_Paradise - looks like a lot of fun! the fire pit is a great idea.
Thanks! I’m getting a lot of helpful information. I’ve been on YouTube and watched a few videos and I vaguely remember seeing a map of soil types in north Texas. In case you’ve never seen that map it looks a little like swirled tutti-fruity ice cream; all the soils in this area are mixed around in random areas. One of the YouTubers recommended looking for clay that was a light color. Is that a good thing to do?
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I assume you’ve already seen this, and I have zero personal experience, but the Caddo were the cats people pointed to when I was a youngster learning about local cultures and the awesome things they could with the resources at hand.
https://www.texasbeyondhistory.net/tejas/clay/making.html
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Not necessarily. Sue harvested some black clay when they were building some of the Las Colinas area, and it was fine. She says that most clay in the metroplex (and indeed, most clay you find) is a low-fire clay. Nothing wrong with that, but it means it doesn’t really vitrefy (or become stoneware). I’ve done a couple of test-fires where I wasn’t sure if the bag of clay that had been abandoned was high or low fire. That YouTuber probably preferred the light clay for the same reason I prefer a white clay. It may be that if it’s light, it’s more likely to be clay, and not just dirt.
And here’s some history for no reason – China had the high-fire clays, and developed the technology to actually get a wood fire up hot enough to take advantage of that characteristic. The vast majority of Europe had low-fire clay. That’s one reason pottery didn’t tend to be valued by the nobility, unless it came from China. Later on, you get stuff like majolica. Germany with its’ salt fired items is about the only European high-fire I’m aware of.
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I checked the clay last time I went out to the barn and it is coming along nicely. I’ll strain it, dry it a little, and might have some to bring to DMS this weekend.
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When I dug my own clay, this is what I found.
North Dallas black clay yard mud (sticky in spring, cracks in dry summer) fires to 05-06 and vitrified around that temp. Fires out a nice Terra cotta color. At cone 10, it makes a nice brown glaze, similar to Albany slip, which is no longer available. The working characteristics are poor, it is very short (not real plastic). Good for brick, not so good for pots. It might be improved by the addition of bentonite, but I didn’t get that far in my research.
At the same time I was able to visit a construction site in Las Colinas, which had been excavated for a large building. Below the black clay layer (similar to my yard mud) was a yellow ocher color layer. It had about the same working characteristics, firing temp, and end color as the black clay. At cone 10, there was a small difference in glaze color.
The process I used to prepare the clay was to soak it in water, pour off any floating leaves, etc. Then run it through a strainer to get out gravel and sand. Then run it through an 80 mesh sieve, pour it out on plaster bats to dry out a little, then balled it up. Most of the balls I put in the freezer for a day or so, then thawed it out, then repeated the cycle until I got tired of looking at it. This mimics the natural freeze-thaw cycle which naturally ages clay. And slightly improved the working characteristics.
I still have a few small pinch pots I made from this clay, and the glaze test. I could bring them in if we want to have a discussion on this topic sometime.
It was a fun project, but I don’t recommend it for the bulk of your clay needs.
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I checked out your clay today and it felt pretty darn nice! Sandy, but I sometimes like that in a clay body. I wish I had looked at Talk during Open House, I was within talking distance of Sue all day and could have brought over a bit for her to look at. It would be interesting at this point to make up a couple of test tiles and dry them slowly, see how it shrinks and moves and then we could fire them on some test trays (in case they go full melt). If you would like some help with that, just let me know. I’m always game for an experiment.
(I put a plastic bat over the top to keep the clay moist, it gets dry very quickly in the workshop.)
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Yeah I took a pinch of it and rolled it in my fingers. It wasn’t plastic at all and twisted off. Sue, I figure it is similar to the clay you tested but is from Kaufman co. and colored brown-gray a little like chocolate milk. Dry its a little more ash gray. Good to hear it would make adequate bricks, though. I’d like to see how it fired as a pot.
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