Clay, Application to Refinement-Steels

The main purpose of a steel is to transform the roughly "sketched-in" clay surface, to a smooth clean surface, ready for the final presentation. Though there may be several levels of steeling until the final clean-up, the steel will remove any unwanted highs and lows on the clay surface when used by a skilled sculptor.

The steels come in various sizes and thicknesses and also in an assortment of different shapes. Many sculptors have a favorite shape which they then scale up or down in size and adjust the steel thickness to suit.

As you can see from the photograph on the right, the steels vary from large to small and are various thicknesses.

As a general guide, use the sizes below:

18"x 3"x 0.030" 15"x 3"x 0.025"

18"x 3"x 0.025" 15"x 3"x 0.020"

18"x 3"x 0.020" 15"x 3"x 0.015"

12"x 2 3/4"x 0.025" 8"x 2 1/2"x 0.020"

12"x 2 3/4"x 0.020" 8"x 2 1/2"x 0.015"

12"x 2 3/4"x 0.015" 8"x 2 1/2"x 0.010"

6"x 2"x 0.015" 4"x 1 3/4"x 0.012"

6"x 2"x 0.010" 4"x 1 3/4"x 0.007"

6"x 2"x 0.005" 4"x 1 3/4"x 0.005"

3"x 1 1/2"x 0.007" 3"x 1 1/2"x 0.005"

This list of straight steel sizes is an indication of what I personally find useful in my modeling kit. It is not complete by any means but would provide a good start for any modeler. Each individual has his or her own set of steels but would follow a similar size pattern.

One side of the steel is left smooth, for final clean-up of the clay surface, the other side normally has teeth filed in for surface development. You will find that during the course of sharpening that the teeth will begin to fade. This is the time to re-cut with a file.

The set of shaped steels to the right represent one shape that has been scaled down and then cut from different steel thicknesses. Each steel being used in its own unique situation.

The thickness for the largest steel is 0.012", diminishing to 0.010", 0.007" and the smallest 0.005".

By reducing the size on a photo-copier machine you are able to repeat a proven shape on a smaller scale, just reduce the metal thickness to suit.

The steels on the right represent another shape but on a larger scale. The largest being 12" long and 0.020" in thickness.

Each one is a reduction of the largest steel.

The steels can be left with a smooth edge or have teeth filed in. Steels that are serrated are primarily used for sketch modeling.

I normally make duplicates of steels that I use on a regular basis. One that is smooth for surface clean-up and one with teeth in, for development work.

To make the various shaped and straight steels, a selection of different thicknesses of blue tempered spring steel is required. This is easily obtained from McMaster-Carr under Blue tempered spring steel shim stock. It can be purchased in 6"x 25", 6"x 50" lengths or in a pack of varying thicknesses.

The photograph on the left shows the pack of blue tempered shim assortment, together with left and right off-set aviation tin snips.

With the aviation tin snips you can cut up to 0.015" metal thickness cleanly without bending the material. Any thicker material should be cut on a metal bandsaw or metal foot shear.

The photograph on the right shows the rough cut steels and plywood support block. The steel nearest to the plywood block has a photocopied steel shape spray mounted to the steel. The three steels are 0.005",0.010" and 0.015".

With double sided tape mount each steel together, then mount to the support block. If you are making several steels of the same thickness mount in a similar fashion.

There is no restriction on how many steels you mount together, although I would restrict it to 3-4 steels. It will just take longer to sand the steels to the desired shape on the disc sander.

If you have no disc sander, it is a longer process of filing to the desired shape.

As you can see, the block with the steels attached has been sanded on the disc sander. Check the steel shape before removing from the block. If there are any irregularities in the form, refine before removing.

The quickest way that I have found to de-burr the steels is to use an oilstone with oil. This will remove the burrs that you associate with grinding the steels to shape and also take away any high spots that are present from the metal forming process.

This will leave you with a nice sharp edge. Any grinding marks on the edge of the steel can be removed by "dressing out" with the oilstone or diamond stone.

Now that we have a smooth edged shaped steel for finishing the clay, the same procedure would be used to produce an identical steel for sketch modeling. The only difference is the teeth that would be filed in with a Swiss file.

As you can see from the photograph below, the teeth have started to be filed in, giving us a pair of shaped steels. One smooth and the other serrated. For additional information on straight steels, go to Steels2.

Steel Shapes A Steel Shapes B Steel Shapes C

Download the PDF files to make the various shaped steels.