LynneBerma@AOL.COM on wed 9 aug 00
Could someone explain to me why the clay gets darker the more I burnish the
terra sigged pot? It must have something to do with compression and water.
True?
Lynne Berman at the Jersey shore
Shelley Corwin on sun 13 aug 00
it doesnt affect the finisphed color, sometimes it picks up silver from a
spoon too. i supposed it darkens from compression=light absorption instead of
reflection. s
Michael Banks on sun 13 aug 00
What tool are you using to burnish with, and what sort of clay Lynne?
Michael
in New Zealand
Lynne Berman wrote:
----- Original Message -----
> Could someone explain to me why the clay gets darker the more I burnish
the
> terra sigged pot? It must have something to do with compression and water.
> True?
LynneBerma@AOL.COM on tue 15 aug 00
Michael in New Zealand,
So nice to correspond such a distance. I was using white stoneware and
burnishing with either a Magic Slider (for use under refrigerators to move
them to clean underneath for those who care about such things) or that
wonderful teflon rib Bob Howell used to make. However, it matters not what
clay. It has something to do with compression I think.
Lynne at the New Jersey shore
Michael Banks on wed 16 aug 00
The reason I asked what you were using to burnish with, is that rubbing a
metal object on clay can darken it due to abrasion. Finely divided metal is
black in colour and enough metal particles are easily abraded off the
burnishing tool to darken the clay.
If the Teflon tool also darkens the clay, this would be due to another
effect (as Teflon is not easily abraded and is not black either). This
could possibly be by greater absorption of light by aligned clay platelets,
relative to non-aligned clay. On a macro scale, white micas (which
resemble kaolinite quite closely) seem to exhibit this quality, being
transparent to incident light parallel to their C-axis (at right angles to
the flat faces) but fairly opaque to light travelling parallel to the A and
B axes (short faces).
Michael,
Nelson,
New Zealand
----- Original Message -----
Lynne at the New Jersey shore wrote:
> I was using white stoneware and
> burnishing with either a Magic Slider (for use under refrigerators to move
> them to clean underneath for those who care about such things) or that
> wonderful teflon rib Bob Howell used to make. However, it matters not what
> clay. It has something to do with compression I think.
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