Making Slip & Easy Hump Molds

To make slip I start off with scraps of my clay body and break them into as small of pieces as I can. I let them sit till they are bone dry.

I take them out of the bowl and put them in a ziplock baggy, seal it, and roll them till they are a very fine particle size.

I put the finely rolled clay back in a bowl and add water to cover the clay completely. If after several hours all the water is absorbed, add a little more water. At this point resist the urge to stir the mixture since this increases the amount of lumps. The idea is to end up with as smooth a mixture as possible.

I let the water and clay mixture sit till all the clay is evenly moistened, usually over night. The next day you can stir the mixture or usually I use a hand held mixer to blend up the slip mixture. Next I sieve the mixture and divide it up into pint sized containers with air tight lids.

Later I can use the slip as it is or add mason stains for colored slips. To mix in mason stains to a pint mixture (about a cup of slip) I start out with a teaspoon of mason stain and wet the mason stain in a small glass bowl with a bit of water. Then I add that to the container of slip till I think the color is good to my eye. Later I put a piece of tape on top of the jar of stained slip noting the amount of stain I have added for that particular color. For more details on mason stained slips click the link to Slip Slop Stain and Mixing Mason Stain Slips.

 Save those styrofoam trays which hold food from the grocery store, they make good hump or slump molds.

For these two plates I turned the trays over and rubbed them with Pam sprayed onto a paper towel. The Pam prevents the freshly rolled clay from sticking to the styrofoam and allows the plate to release more easily. For these two plates I rolled out a slab of clay and textured them.
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Then I draped them over the upside down styrofoam tray, let them firm up a bit then flipped them over and let them dry on a piece of wallboard till dry. Don't let the plates dry completely on the hump mold since the clay shrinks (contracts) as it dries and that may warp the plate. Once they were dry I sanded the edges with a green scrubby (wearing a mask). Dry clay is harmful to the lumg so please wear a mask. These two plates are in the kiln being bisque fired. Thanks for reading and for all your comments..

That's Not Pancake Batter & Cleaning Kiln Shelves

This time I used warm water when I made slip and it softened the bone dry clay much better than cold water. I covered the bone dry clay with the warm water and let it sit for several  hours without stirring till the clay is all softened. Then I stirred the slip really well. I didn't even need a mixer this time. I left the slip sitting on the counter for a couple of days because I had added too much water and wanted some of the moisture to evaporate. Gary asked if I was going to make him pancakes. I said that's not pancake batter, sorry. I use the slip for attaching the seams in clay and also for mixing with mason stain colors to brush on the clay for decoration. For more details on how I mix slip and stains, see out my previous post Slip, Slop, Stain.

I've had my kiln for two years and I've never cleaned the shelves. I've been extremely careful with glazing but it was time to clean them. Shame on me; it wasn't as difficult as I thought. I have 21 inch half size corelite shelves. I can carry a shelf with one hand hanging down; they're really light weight. I brought a table outside and put a piece of thin foam with newspaper over it and placed the dirty shelf on that. I wore a mask that filters fine particles and safety glasses. I scraped the old kiln wash off with a metal putty knife and any glaze drips. I dusted off the shelves and took a damp cloth and wiped off any remaining dust off the shelves. Then I re-coated the shelves with kiln wash. I noticed there's a divot (small depression) in two shelves from the plucking of one plate. Is there some way to fill in those low spots?

It takes at least three hours for the kiln wash to dry completely between coats. I put two coats on; one in one direction and the other in the opposite direction. I mix the kiln wash like thin cream. The kiln wash doesn't appear thick enough till it dries so it's easy to think I'm not getting coverage. After the second coat I let the shelves dry over night. Now I'm ready to do some marathon firings. My cabinets are overflowing with lots of plates and bowls. I better get busy. Thanks for reading and for all your comments.

Blue and Green Slip

All of a sudden it's cold outside again, so I decided to stay inside and continue my slip slop stain experiments. Remember this pinched porcelain bowl I made as a warm up after the holidays? Now I've used this same bowl to experiment with my first batch of sky blue slip. I decided to use a butterfly shape as a contrast to the colored slip. My pinched bowl is now a butterfly bowl. I don't have a clue what I'll do after I bisque the piece. Will I put a clear glaze over it? I'll wait to see how it turns after the bisque firing, then I'll decide.


A few weeks ago, I did some clay weaving. Today I put some of my green slip in a pattern on the woven tray. I do have a glazing plan for the remaining sections of this piece. I'm planning on using a matt yellow glaze with temoku accents over the top. I'll use clear glaze over the green stained sections.


Here's a porcelain wall pocket I made a few weeks ago. Again I am using a butterfly shape to contrast with green slip. I've no idea about the final outcome of this piece. That's half the fun of using clay as an artistic medium. Will it be glazed, pit fired, barrel fired, time will tell. Perhaps I will try it in a barrel firing. I'm still trying to get enough stuff bisqued for the barrel firing, hopefully next weekend I'll at least have one barrel firing.


This weekend I went to the feed store to get some straw (which was the last ingredient I still needed for my barrel firing). I noticed they had bales of rice hulls, so I got one bale. I knew I had read something about rice hulls before but couldn't remember what.

Now that I'm home I read rice hulls can be hard to burn, so perhaps I'll mix them in with some straw. I also read rice hulls contain large amounts of silica, but also contain sodium, potassium, calcium, magnesium, iron, copper, manganese and zinc. I plan to save the rice hull ash from the firing for future experiments. Wonder what would happen if I mixed some rice hulls into some wet clay? Or coffee beans - I think I remember something about them too. It's never ending, isn't it - so many ideas for clay and so little time.

How about you? What experiments have you done? Or what experiments would you like to do? Comments and advice are always welcome.

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.