Roger Korn on thu 22 nov 01
Paul,
Why is tin necessary for COPPER reds? I have no clue yet, but I'm going to find out
somehow. When I grind thin cross sections of copper reds on porcelain and look at
them through a microscope using polarized light, I see several transparent layers
that comprise the glaze. Some sort of dichroic refraction/reflection at the
interface between layers may account for the red, but this is a guess.
Maybe iron reds are a similar phenomenon. Pure conjecture on my part, but I'm
looking for access to a scanning x-ray diffraction microscope to see if I can
investigate further. Robert Tichane has done some work in this area. I'll reread
his stuff on copper reds before proceeding. Just curious - the beauty of iron reds
is impressive even if Unknowable Magic is accountable.
That is one of the ways ceramics grabs me - every time I open a door, I find
another bunch of doors staring me in the face. Boredom seems extremely unlikely!
Happy Thanksgiving!
Roger Korn
McKay Creek Ceramics
In AZ: 928-567-5699 <-
In OR: 503-647-5464
Paul Lewing wrote:...
> I don't know why tin works better than zirconium in this glaze, or why the
> phosphorous in the bone ash helps in the development of this color, but I do
> know those are both true.
> Paul Lewing, Seattle
>
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