Home > Listing of Enamels > Vintage EnamelClick Image To View Larger 50-A White (op) Hard Fusing! $8.00 Weight 1 oz ($8.00) 8 oz ($64.00) 16 oz ($128.00) 6050:=:8,6055:=:64,6056:=:128 Quantity: - + Opaque, cataloged, Thompson Enamel for Copper, Silver, Gold, Iron and Steel. This enamel is "hard fusing" and should be fired at 1500 to 1575 degrees F. for approximately 2 to 4 minutes. All Enamel is pre-1990, 80 mesh and lead bearing.