Thursday, February 5, 2009
Slip Slop Stain
I've been wanting to experiment with some colored slips. I decided to try mason stains, since there is such a wide range of color choices. The perfect opportunity came when a green ware, palm tree sculpture I was moving fell on the floor. It was broken beyond repair. It took me forever making all those palm fronds and propping them up with crumpled pieces of paper bag. Boo Hoo! But it'll make the best slip, right?
I broke the sculpture up into a bunch of little pieces and laid them all out to dry out. One of my classmates walked by and was staring at the ware board of clay particles with a quizzical look. So I said to him (very seriously), "How do you like my sculpture?" He said, "Very nice, Linda". I replied, "I call it free form sculpture". He said, "OK, Linda". I didn't want to keep him in suspense so I told him what I was doing. Perhaps I should have just let him wonder. I took all the pieces of clay home to set them in the sun the next day to dry.
I usually mix up my slip with a large metal tablespoon. This time I wanted my slip to be real smooth, so after I let the dry clay slake in water, I took the bowl outside and mixed it up with my hand held mixer. It came out real creamy. Notice my professional looking cardboard box table top on the gravel driveway. It's supposed to rain tomorrow so I wanted to get this mixed up today. I sure wasn't going to mix it inside, clay would have splattered everywhere.
I am calling the 'real', scientific method of measurement I'm using a slip slop stain. I make up some slip, I slop it into a container and I add some stain. It's not quite that haphazard, but it isn't weighed either. I am using a type of volumetric measurement described recently in Ceramic Arts Daily.
In the article Sumi Von Dassow recommended using 2 tablespoons of stain for 8 ounces of glaze. That's about 12 percent stain. I want to try 5 percent and 10 percent stain in my slip. One cup of slip is 48 teaspoons or 16 tablespoons. Five percent of stain would be 0.8 tablespoons or 2.4 teaspoons and ten percent of stain would be 1.6 tablespoons or 4.8 teaspoons. I read when firing Cone 10, I should need less stain than I would at Cone 6, the opposite of what I would normally think. A higher temperature makes a brighter color with less stain. I know I'm putting the stains in slip not glaze, we'll see what happens.
Surely Jane Peiser and Vince Pitelka would cringe at my slip slop stain description and methods, but we all have to start somewhere with our experiments and I am beginning here. I will be testing Sky Blue, Ivy, and Best Black, mason stains. I am adding these to my porcelain slip and I will be firing to Cone 10. I may also try the same stains on my Soldate 60 stoneware body to see how they react with that clay body. I also want to try come colored clay inlays too. Whoh! That's a whole lot of experiments.
If you have any advice or experience using stains, please share. What do you store your small batches of slip in? I've got some small plastic containers I purchased in a pack of three and some larger ones I picked up at the dollar store. If I don't run out of time and slip, I'll also try some Copper Carbonate, Copper Oxide and Red Iron Oxide combos too.
Now that I've written all about the mixtures I'll be making, I better get off my d**f - uh, garden bench - and get busy making my slip slop stain. Look for more experiments in the future with Frit 3134 and some Nickle Oxide? Comments and advice are always welcome, this mad scientist can use all the help she can get. Toodles for now.