Ceramic Figurative Sculpt, 'Morning Cuppa', Firing Problem Caused Failure
by CliftonSears in Craft > Art
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Ceramic Figurative Sculpt, 'Morning Cuppa', Firing Problem Caused Failure
This instructable is about creating a stylized figurine in ceramics.
The idea is to communicate your concept through the figures form and position with minimal use of detail.
It is a great way to work with figures in clay. You can place less emphasis on proportions, and more on creating something interesting. An upside is that, If you make many figurines, you will develop a better feel for proportions and pose. It can be a loose, creative way to work.
The technique used to make this figure is to forming the clay from the ground up, with only a little support as needed. This approach works well for a piece like this.
You can the methods described here to copy along, if you like, or apply it to own concept.
I like to make these type of figures entirely from my imagination and not refer to pictures or posed friends. But you should use whatever method you feel comfortable with.
Concept
Of course, it begins with an idea or image in your mind's eye. To help solidify the idea, you can ask someone to pose, and take pictures or make some loose scribble drawings. I made a few such scribbles when I wanted to work out how best to position the hand that supports her head.
I am working with a purchased, white firing, stoneware, sculpture clay. This method will work with any clay as long as you use good binding methods and fire slowly or pre-dry in an oven. More on that later.
I don't knead, or punch, or jump on purchased clay. No need to beat it into submission. It comes ready to use from the manufacturer. If it has been stored for a while, as this was, I will add about 1/8th cup of water to the bag in order to keep the clay moist and soft to work with. It will absorb into the clay over time.
I use a wire with sticks on each end to cut off a hunk and form it with my hands. You can use almost any wire you have available to make one of these.
The base I used for this piece is a plastic bat, normally used on a potter's wheel. It is 12 inches in diameter. Old pieces of laminated desk, cut out rigid plastic, or any flat, stiff surface will work. It mustn't bend or flex. If the surface is slick, you can rough it up with sandpaper to allow the clay to stick.
Since the clay is moist, I can just mush pieces together to create the basic shape I am looking for. I like to keep the walls of the form fairly thick. The photo doesn't show this well. Thick walls give me room to remove clay from the outside later.
Initial Form
In the first sitting I can usually establish a basic form. I built up the figure to this point by adding pieces of clay and shaping with my fingers. The clay is supporting itself.
The arms are made solid as they are not thick enough to be a problem in firing.
I seldom have a lot of hours to work on a given piece. To keep it moist and ready for the next session, I store it under a plastic bag.
If I can't get back to it for several days, I will sometime mist the clay with water from a spray bottle.
Finishing the Basic Form
Making the piece in a few steps has the advantage that the clay stiffens as it dries out a little, and can better support itself. Otherwise it is necessary to build a framework to support the clay while it 'sets up'.
The weight of the head makes a support necessary. In this case I used straws that have the flex joint in them. Make a bend, cut with scissors, and push in place. A little bit of clay will hold it at the base. For more elaborate support you can use a small, hot glue gun to make a straw framework.
The little ball on a stick allows me to push from the inside of the figure, while shaping the outside. The ball is purchased from a hardware store and in this case glued to a chop stick. A dowel works as well.
The scraper I used for removing clay and shaping was made by bending a paper clip, and gluing it in the end of a dowel.
The head is too large to leave solid. I make it hollow by balling up some tissue, and forming clay around it. If someone else is firing your work, you will need to make a small hole into this cavity. Perhaps under the chin or under the hair at the back of the neck. Those plastic stirring straws, used for coffee, will make a nice small hole. Since I fire my own work, I don't need to do this. More on that in the firing step.
OK. The basic form is finished. Time to step back and think about it. I was aiming for something more abstract, but it looks OK. I think I'll add a house coat to give a morning feel. Partly open to add a little detail. Hmmm. And maybe draped just so to add interest ...
I add a little water with a paint brush, to make sure the clay I add will bond well with what is there. I use a stiff bristle brush at this point and use a soft brush for smoothing the surface of the clay. don't get too mush water on clay or it will get too soft to work with.
Final Work Before Beginning the Drying Steps
It will usually be necessary to leave the supports in place for at least a day of setting up under the plastic. In this process water is migrating from the inside of the clay to the surface and the form shouldn't be bent again. It can crack or sometimes return to its original position as though it had memory.
The final smoothing can be done and any marks from supports can e filled in and smoothed over.
It was at the point that my better half saw the work. She looked at it in surprise, and exclaimed, "Her boobs are on the table". Taking great delight in this she said, "I like it." And, after much chuckling, " It's OK honey. Some mornings mine are resting on the table too."
After recovering from the artists angst, I decided to press on.
The next step is to set it aside for drying. It should not be completely dried just yet. The goal is to have it dry enough that it separates from the base. I leave it open to the air. In a cool place it will take about 3 days. In a warm dry environment, it can be ready the next morning. You can use plastic to slow this process. Don't rush it. the gallery will wait.
Drying and Ready for the Final Finishing.
After 3 days in a cool and slightly damp place I check in on the piece.
It had separated from the base and was dry enough to pick up.
Be very careful, the figure is very fragile at this stage and can be easily broken.
Now is the time to trim off the edges with a knife and fill in any thin areas on the inside of the body. Also a perfect time to smooth out under the arms and such.
But ... I was working night shifts and off to work. To make matters wore I left it out on my work bench where it is warmer and dryer.
I should know better ... in the next step I deal with the consequences.
Repairs
The piece dried too much too quickly and cracked on the sides where the clay was thinnest and dried more quickly.
Decision time.
It might be wise to just crumple up the work, toss it in a freezer bag with a little water and reuse the clay. Clay does seem to have memory and the cracks could return in firing. Still, it is a fair amount of time invested and the clay is not that expensive.
I use a knife to trim off the clay edge and cut in where the cracks have formed. Then moisten the figure with water.
Next I mix up a paste of clay and vinegar. This will be my filler. I also have a small amount of vinegar to brush into the cracks. The acetic acid in the vinegar will help the wet clay penetrate into the dryer part and may make the repair a success.
After the repairs are made I spray the figure down with water 2 or 3 times and set it under a plastic bag with a small container of hot water. Later that day I replaced the water with fresh hot water. The moisture will penetrate into the clay and I will dry the whole thing a little more carefully this time.
You might notice that I cleaned off the base so as to give a smooth flat surface to set the work on for final drying.
After a lot of attention over several days I managed to get the piece dry and without any obvious cracks. It might fail in the kiln but it looks ok. Given the problem in drying, I decided to do a single firing and coat the work with a copper finish glaze. I had made another partial figurine and did the same with that one.
Firing Fail
I have a new setup with a different kiln, home made kiln vent, and metal heat shield. This one is a small doll kiln and fits my work methods a little better. The ramp / soak temperature controller is the same, with a relay used to turn the kiln on and off, but a problem with the sensor caused the temperature of the kiln to rise too quickly.
The wires leading to the temperature sensor had crossed during the installation, and were touching each other. The controller did not sense the temperature properly and kept the kiln on more frequently, resulting in a quick rise in real temperature.
Both figurines went pop in the kiln as moisture converted to steam. The figures were in a hundred pieces when the kiln was opened.
Oh well. I should have known better. After this kind of work on a kiln, a test firing is a must.
I decided to post the instructable anyway, just to show some of the things that can go wrong when working in ceramic sculpture. Especially if you follow my example and get overconfident or careless.