Layering Over Sgraffitoed Liquid

I make light switch covers that are site-specific functional fine art and sculptural vessels that are not at all functional. I sgraffito my design into dried Thompson's #533 liquid white enamel base coat. I layer transparent, opaque and opalescent enamels over it in many firings. The white liquid enamel base coat over the metal is similar to a coat of gesso over canvas in oil painting. In subsequent firings, the layers go from transparent to opaque or dark to light.

I usually enamel on 18 ga copper. I form my switch cover shapes from copper sheet pressed in a hydraulic press with a masonite die. I either buy copper vessel shapes and alter them or I fabricate them from copper sheets. I like either to cut holes in the vessels or cut pieces out of them and then sew the pieces with copper wire or rivet copper pieces over the holes.

The copper is cleaned by firing the pieces in the kiln for about a minute at 1500°F. After the copper cools, I remove any loose firescale with a toothbrush. The base coats, front and back, are applied with an airbrush in the spray booth. I usually clean and spray several pieces at the same time. Thompson's #533 liquid white needs to be stirred until all lumps are dissolved and also diluted with water, if need be, to the right consistency for the airbrush. I prefer the even coating the airbrush can achieve. An uneven application usually results in a myriad of colors and textures. I spray only a small amount of the liquid enamel at a time because the heavier enamel particles tend to sink and must be agitated to keep them dispersed in solution. The airbrush needle is set way back in its tip, and the aperture is wide open to keep the heavy enamel material flowing evenly through the airbrush. When all pieces are coated, they are dried with a heat gun. Industrially, this is called "bisquing" because drying at 1200°F creates a very hard surface.

The hard surface of dried, white, liquid enamel is sgraffitoed with a sharpened bamboo skewer. The pieces become drawings, sometimes with very noticeable strokes, sometimes with different width lines or with large areas of exposed copper created by first scratching with the skewer and then brushing the enamel away with a soft brush.

If I am working on the three-dimensional vessel forms I will spray all sides with #533 and sgraffito all sides. If I am working on switch covers, I will brush a Thompson liquid counter enamel on the backs of the covers after sgraffitoing the fronts and then sift 80 and 100 mesh enamel over the still wet counter enamel.

The switch covers, with both sides coated for the first firing, are fired with the white side down on a point rack. The points are coated with kiln wash and allowed to dry before they are used. The vessels are fired concave side down on either a trivet or a fired support constructed for the piece. I fire to maturity at around 1500°F. The kiln I use is an old 220V Vcella with a fairly large chamber. It is very energy efficient and retains an even heat.

After the first firing, the pieces are put in a Sparex 2 bath to remove the firescale that has formed over the exposed copper lines and spaces, then rinsed well and dried. My procedure of layering has developed as my knowledge of enameling has grown and as I have learned about the three-dimensional aspects of the color I am working with. The first layer of enamel over my sgraffitoed surface is a sifting with a 150 mesh sifter of never more than four or five colors of Thompson's #150 mesh lead free transparents. I overlap some of the transparent enamels to suggest an under-painting that I will develop with subsequent layers. On the three-dimensional vessels, I airbrush diluted 1:4 Klyr-Fyre before sifting. The wetted particles must dry before I fire. This layer of sifted transparents is fired to orange peel at 1500°F. When they come out of the kiln, the switch covers are weighted with a press plate to minimize warping. The heat changes the vessel forms slightly during cooling, and I incorporate these changes while I create the piece.

The rest of the firings involve applying thin layers of wet enamel, gradually building toward the depth and color contrast I want. I am looking for very subtle colors with an opalescent quality that play against the first layer of transparents, which I have fired over white and over copper. The order of application before each firing is to apply wetted particles, dry the enamel, sift flux and fire. The enamels I use for wet application are 325 mesh Thompson lead free opaques, Japanese opalescents and a few miscellaneous enamels that have been spooned into watercolor palettes and a few drops of tap water added. With a brush, I push and pull the enamels, not wet packing, but using the water to guide the particles. I like to bring the particles as close to my sgraffitoed lines as possible. I tend to use the lines to form boundaries between various colors. I also like to mix enamels for subtle shading on a piece. After the wet particles have dried and before firing, I dust on a very thin layer of flux with a 150 mesh sifter. The flux I use is Blythe C-10 from England. It has a slightly yellow cast. The flux minimizes break up, especially from the lead free opaques. I slightly underfire though with the kiln at 1500°F. As the layers build, I may fire at a lower temperature or for a shorter time to control the amount of transparency I want as the underlayer of white becomes more transparent.

At various stages, I add glass elements such as balls, squares, slivers, threads and beads as accents and to give texture. I may also incorporate gold and silver foils in the later layers. The foils act as accents and also add to the imagery of the work. The foils I use are the thicker Japanese ones, some with a black overglaze pattern, and the thinner Thompson foils. I seldom cut foil pieces larger than one inch. The foil is placed in position with a wet brush and held in place with a drop of diluted Klyr-Fyre. Before firing, I sift a layer of Japanese silver flux (N-1 or S-302) with a 150 mesh sifter over the whole piece . The Japanese flux is softer than the Blythe flux. I continue to use the Japanese flux for any subsequent layers I might need once I have placed foil on a piece. I sometimes wet the piece to float some 60 mesh or coarser transparents over the fired foil and flux to give it color and then fire again.

I sign my name on the front of my pieces with Thompson's P-3, underglaze black, mixed with pine oil. When the signature is dry from being on top of the kiln, I sift on a thin layer of flux for the final firing. It takes from six to sixteen firings to complete one of my enamel pieces.

One option for finishing the enamel surface of a piece is satin finishing that I do for my vessel forms. I first file away any oxidation on the edges and then glass-etch the surface first with B&B etching solution and etching cream. This brand seems to be less toxic than others. I then use abrasive papers to arrive at the finish I want. I have a tub of water sitting by my finishing station. I dip the piece and the papers in the water and change the water as it gets cloudy from use. I start with 800 grit diamond cloth (a diamond impregnated rubber pad), then go to a silicon carbide paper. I progress from 1000 to 1200 to 1800 to 2000 grit silicon carbide papers. All the work is done by hand except for any nooks and crannies where I use 3M impregnated bristle discs on my flex shaft.

The pieces I choose to satin finish are the sculptural, "destructed" vessel forms that I call "Burnt Offering." These pieces reflect the conflicts I often feel in working with enamel. I view enamel as a rendering medium but when used on a three-dimensional form, the rendering must be in harmony with the structure and yet be more than decoration, pattern or design. These pieces must be precious and show the possibilities of ultimate control of the medium and at the same time must seem to be dissolving in chaos and destruction, never to be used to fulfill a function.