August 30, 2010 9:46 PM EDT
Since my detail from a panel I did is the header photo here, I thought I'd put a few notes on this piece. The copper is 18 g, and was made by inlaying a choice of heavy cotton lace sections from an old tablecloth into the asphaltum resist before it was completely hardened. I pushed it into the surface to contact the metal, and when very set, but not hard, I pulled off the lace carefully. This pulled resist from the lacy patterns, and the reverse was also covered to protect it.
 I etched it in a nitric acid bath in a pyrex dish, under a fume hood. To remove bubbles forming resist in unwanted portions, I used feather brushing to push away bubbles developed on metal exposed in the etch. This was in a school environment with correct precautions are easily taken. I have since found the ferric chloride etch is less undercut. But the undercuts appearing in this application were not objectionable.
After messy cleaning with petroleum solvents, mineral spirits, I cleaned all traces of oily residue, and applied counter enamel in a thick layer to a depth appropriate for the coming front layers. Cleaning the etched front of fire scale, the etch was not harmed.
Most of the enamels are leaded, Thompson, and applied with light Klyr fire and sifting. Be sure to wear dust mask protection and clean the area.
Layers of enamels were fired quite hot and fast, and clear. Because of the deep etch, it's a favorite panel of mine.
Terry Brake
Since my detail from a panel I did is the header photo here, I thought I'd put a few notes on this piece. The copper is 18 g, and was made by inlaying a choice of heavy cotton lace sections from an old tablecloth into the asphaltum resist before it was completely hardened. I pushed it into the surface to contact the metal, and when very set, but not hard, I pulled off the lace carefully. This pulled resist from the lacy patterns, and the reverse was also covered to protect it.
 I etched it in a nitric acid bath in a pyrex dish, under a fume hood. To remove bubbles forming resist in unwanted portions, I used feather brushing to push away bubbles developed on metal exposed in the etch. This was in a school environment with correct precautions are easily taken. I have since found the ferric chloride etch is less undercut. But the undercuts appearing in this application were not objectionable.
After messy cleaning with petroleum solvents, mineral spirits, I cleaned all traces of oily residue, and applied counter enamel in a thick layer to a depth appropriate for the coming front layers. Cleaning the etched front of fire scale, the etch was not harmed.
Most of the enamels are leaded, Thompson, and applied with light Klyr fire and sifting. Be sure to wear dust mask protection and clean the area.
Layers of enamels were fired quite hot and fast, and clear. Because of the deep etch, it's a favorite panel of mine.
Terry Brake
