Jose A. Velez on fri 15 nov 02
Tom, Snail, Roger, Hank et al:
Thanks for your comments on the Oxidation Vs Neutral Firing. It has =
been a revelation to me that an unvented electric firing might be a weak =
reduction atmosphere. Two mechanisms might be involved. In a small =
space heating the air to high temperatures will sharply reduce its =
density, therefore less total Oxygen. Then the effect of the off-gases =
from the clay and glaze, mentioned by Roger, can further contribute to =
the Oxygen starvation. Hard to argue with the observed differences in =
clay color during bisque firing.
Thanks,
Jose A. Velez
John Kimpton Dellow on sun 17 nov 02
This very true and especially if one is firing cadmium/selenium
glazes .
The kiln needs venting. While on cadmium/selenium glazes do not
put lead
,fritted or otherwise ,glazes in the same firing .
"Jose A. Velez" wrote:
>
> Tom, Snail, Roger, Hank et al:
>
> Thanks for your comments on the Oxidation Vs Neutral Firing. It has been a revelation to me that an unvented electric firing might be a weak reduction atmosphere. Two mechanisms might be involved. In a small space heating the air to high temperatures will sharply reduce its density, therefore less total Oxygen. Then the effect of the off-gases from the clay and glaze, mentioned by Roger, can further contribute to the Oxygen starvation. Hard to argue with the observed differences in clay color during bisque firing.
>
> Thanks,
>
> Jose A. Velez
>
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John Dellow "the flower pot man"
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