Using Bisques Clay As Armature

[jolieo]

Hi I have this figure of a woman w a hula hoop , haunting me. I want to make her, she of course w need an armature.

So two different takes on the armature: first : make her bones out of bisques clay . Would the bisqued clay take the clay being bisqued around it without causing structural problems? The whole thing would probably be paper clay.

Second idea : using a burn away armature. My pieces wouldn't be that thick so the material would have to be something like toothpicks. Would this be feasible or just a mess?

Any thoughts appreciated. Jolie

[Benzine]

Bisque clay, would not be a good armature. It would not shrink, along with the clay, causing cracks in the fresh clay, as it dries.

 

Wood, even toothpicks, would cause the same issue. The toothpicks, would have a bit more give, than the bisqued clay, but still would prevent the clay from shrinking normally, leading to cracks.

 

The metal armatures artists use, are temporary. They are kept in, just until the clay stiffens enough, that they can be removed, to allow the work to dry on its own. Other times, the clay work is just used to make a mold, to cast other materials. In either case, the armature is not kept in past the leather hard stage or so.

 

I've used external support, made from slightly dry chunks, of whatever clay body I am using. They are easy to form to the exact size needed, and dry at the same rate as the artwork. Usually, by the time the work has dried, I no longer have need for them. However, I generally make the supports hollow, just in case I do feel the need to fire them with the artwork.

 

I have used newspaper and cardboard as support before. The newspaper offers just enough support, while allowing the clay to shrink. Of course this is usually in large hollow forms, where there is space for the newspaper to expand a bit to the sides as it is compressed. The cardboard compresses less so, but didn't cause any issues.

[neilestrick]

Any time you put something hard inside the clay there's a good chance of the clay cracking as it dries. The clay shrinks, the armature doesn't. You may be able to get away with something small like toothpicks if the sculpture itself is not really small and thin. It is possible to build without an armature by building it in sections and joining them when they are leather hard, or by building it solid and then cutting it open and hollowing it out.

[Pres]

As Neil says, you could build this in sections, when pieces are cheese to leather hard. It may take some supports externally to help with stability while joins dry but it is doe-able. When you work with clay there are several concerns that need to be addressed. 1) Choice of clay body appropriate for the project-some clays will slump in firing or have a higher shrinkage than others. 2) Shrinkage of the clay body-some clays have a lower shrinkage rate than others making them more desirable for some forms of sculpture. Sculpture clays often have grog in them to help control the shrinkage and give them a wet strength. 3)Firing range-When doing sculptural projects, the firing range of the clay can be very important. Firing a body close to its vitrification point will raise the possibility of pieces slumping when they are thin, and unsupported. Clays with a wider range may be more acceptable compromise in this case. 4) Joins must be solid, as the stress on the joint of an unsupported arm or leg compromise that piece in the firing. I have had student work that I placed in the kiln, on a shelf that had supports made of clay to hold delicate areas in place during firing. These were often pierced with holes throughout to keep them from blowing in the firing. They were sturdy, but not joined to the sculpture. They were also put on the sculpture before it started to dry so that supports and sculpture could shrink together on the kiln shelf.

 

These are just a few of the things I can think of to help you when considering this project.

 

best

Pres

[Rae Reich]

Pres kind of threw away an important tip : build your sculpture on a kiln shelf, or piece of one, so it can be loaded into the kiln more easily. A sheet or two of newspaper on the shelf before building will let the base shrink while drying without cracking.

[Rebekah Krieger]

somebody pointed me in the direction of mary susan cate when I was asking similar questions. If you look at her facebook photos you can see how she builds things up without armatures.  

[yopi]

First, how big is this girl gonna be?

If it's just 60 cm tall you don't need any kind of armature. The maximum thickness is about 3 cm (about 1 inch), and your clay body must be heavily grogged (about 25%). This gives not much plasticity but that is something you don't need much in sculpture.

This girl in the photo is life sized and doesn't have any kind of armature inside her. No structure whatsoever.
So go for it, just use the right kind of clay. Raku clay is always good for sculpture.
I use the most amazing clay in the world, but you can't get it outside Mexico. It's called Barro de Zacatecas (zacatecas clay)