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an 'almost there' cone 6 ox copper red

updated mon 15 jan 01


David Malicky on sat 13 jan 01

I tried to develop a cone 6 ox copper red last year, and below is the best
of the experiments. It's loosely based on a Herbert Sanders c10 recipe.
The 'philosophy' of this one was to keep the alumina low for the red,
but max out the silica to prevent runniness. It seems to work - its only
moderately runny, and a nice bright red - BUT pinholes remain, no doubt
due to the SiC.

I offer this recipe for anyone who wants to do some experiments to improve it,
as I couldn't find a cone 6 ox cu red recipe that had decent color.

I did try subbing some Silicon (the element, not SiC) from Micron Metals
( but it was probably too fine (1-5 micron) as it
seemed to have burned out (no red). They also have 325 mesh, or
custom mesh, but I no longer have time to pursue this one.

Other things I have tried:
+2 Zinc - no effect
+5 3110 - no effect
+5 Silica - dull red
+0.5 RIO - dull red
+4 Bone ash - ugly lite purple

More ideas to try:
- cone 7
- a soak

I'd love to hear if anyone makes any progress.


SLD4 Copper Red w/ pinholes c6

Kona F-4 28
Frit 3110 28
Frit 3134 18
Zinc oxide 2
Flint 22

Tin oxide 0.9
Copper oxide 0.14
Silicon Carbide (1000 mesh) 0.14
Veegum 0.7
Bent 1.5

Na2O 0.44
K2O 0.09
CaO 0.38
CuO 0.01
ZnO 0.09

Al2O3 0.26
B2O3 0.25

SiO2 4.07
SnO2 0.02


Expansion: 79.2

David Malicky
Mechanical Engineering Department
Valparaiso University