Monday, May 16, 2011
Florida Clay Slip
Ever notice if you like something your eye naturally seeks that item out? For instance, if you like chocolate, your eye naturally hones in on chocolate at the grocery or bakery, doesn't it? I like clay, so when I drive around I can't help but notice clay soil. That's just what happened to me recently. I noticed some rich red clay freshly unearthed in my neighborhood and being laid down as a base to a road widening project. Like a choco-holic I just had to have some of this red clay.
Doesn't it help to have the whole neighborhood involved in your pottery? I think so; and in my case it's true. Here's my neighbor, Jerry, the one who rode his golf cart to get me the trash can full of clay from the construction site. He stopped by the next day to find Gary and I preparing a small batch of the clay soil we took from this trash can full he brought to us.
Here's Gary pulverizing clay clods for my test batch. I put a small amount in a paper bag and Gary used a rubber mallet to break up the clods of clay.
Here's the sieve I'm using to sift the clay. I've placed it on the tailgate of Gary's truck parked in our front yard. The perfect location for preparing clay, don't you think?
I don't have a ball mill and I'm not mixing perfect terra sig like Ben Carter does. I guess I'm really making a fine Florida clay slip.
Maybe it's my imagination, but this clay soil seems much finer and more red than the last batch I got from a similar location. The last batch was loose soil, sandier, and more orange in color. This soil is deeper red and is in clods, maybe it's finer clay with more iron in it. Tomorrow I'll give the soil my finger test. I'll take a small amount and rub it between my thumb and index finger and feel the consistency. Here's what the freshly sifted clay looks like.
Here's the sifted clay with water added to it. I stir it up really well and then set the mixture aside to sit undisturbed for 24 hours.
After 12 hours I only have about 1/8 inch of small particles. Not sure if you can see the small color difference at the top of the soil line. The theory here is the water goes to the top, the heaviest clay particles or sand settle to the bottom and the finest clay particles are in the middle, floating on top of the heaviest clay particles.
After another twelve hours, I will siphon off the water and then slowly siphon out the finest clay particles, being careful not to disturb the bottom layer of larger clay particles. I'll brush a little of this fine Florida clay slip onto a test tile in my bisque load. Normally I brush my slip on wet clay, not sure about putting it on a dry piece.
Update: this clay is smooth as silk between my fingers, not gritty at all, and I didn't even strain it. I put some on a few flowers for this bisque load, fired them and the kiln is cooling down right now.
Time will tell about this native Florida clay, but I had to try using it. And there are many more experiments in this kiln load. Please stay tuned, it should be intereting.