Formula (by Volume)

• Gerstley Borate 8 cups
• Bone Ash 2 cups
• Copper Carbonate .5 cup
• Cobalt Oxide .25cup
• Optional: Cobalt Carbonate 2%

How Robert Piepenburg fires this glaze –

Apply the glaze using almost any method: spray, pour, brush, or dip. Fire in oxidation or reduction to approximately 1875F. Pull piece and place in a bed of straw in a sand pit. Then cover the piece with a metal container pushing the rim into the sand and wait 3 minutes. Burp the can for ½ a second, then wait until piece cools (15 to 45 minutes). Feeze the colore and finish cooling by spraying with or dunking in water.