Saturday, September 25, 2010

Earthenware, Round 2

Joe and I spent a little time this afternoon looking over the second round of my earthenware tests. Once again, I was really happy with the results-- the vivid purple-reds and rough texture give the clay a unique look and a lot of depth.

When I was finished making my tiles and test pots, I mashed all of my remaining test scraps together and made a bowl. I covered it with sig left over from my class at Arrowmont with Joe Pintz, and...taa daaaaa--my first official (usable) earthenware pot!

The bottom even got a wee bit of flashing around the wads!

The winning recipe (so far...but I've only done 31 blends...) consists of:

83% Ivey Red (named for Ivey Construction, the local company that digs it for us)
5% Silica
7% Fine Grog
5% Wollastonite

Running a close second is:

68% Ivey Red
10% Yellow Banks 401
5% Silica
3.5% Each Fine and Coarse Grog
10% Wollastonite

I'm going to mix up a few more tests based on these two. For my previous tests, I had kept the grog at the level of our current stoneware clay, but since Joe isn't interested in earthenware, I'll probably increase it for my handbuilding. I did have some problems with my clays cracking while drying, and I hope increasing the grog will reduce that issue. Now if we could just get that jaw crusher of our dreams, I would toss in some of the red bricks we salvaged from the former "walkway" on our property and make myself some red grog...

We are going to fire next weekend, but the entire kiln will be taken up with stoneware so I won't be able to do any tests this time. I need to get started on the inevitable hundreds of glaze tests I have in mind, though, and fortunately a friend has promised me space in an electric or gas kiln this winter.

Speaking of winter...

We're ready! The wood is cut, and we cleaned the chimney last weekend. We have a little fire going tonight even though it's only in the 50's. Sweet.



Pat said...

Congratulations, Christy, on your continued progress with earthenware. I love your bowl, but what is sig? I love your blog!

Joe and Christy said...

"sig" is terra sigillata, pat. it is a very fine slip that is often burnished to a shine--think of red and black ancient grecian urns. when it is applied without burnishing, it gives a more matte finish that allows the character of the clay to come through.

although i initially felt lost without good written resources on local earthenware clay bodies, i am feeling all the more confident for finding my own way!

ang said...

nice one, congrats on the testing and i hope you get there soon:)) mmm a lil fire,, mine's still going as it's still chilly here... nice....

Ron said...

Good to hear you are having success. How's the porosity? I look forward to seeing were this goes. I know you'll make some great earthenware pots.

Lara O'Keefe said...

You two always inspire me with your diligent testing!!!

Joe and Christy said...

we are a little on the testing-nerd side, lara!

ron--the absorption tests on my clay bodies have been between 8 and 15%