Paul Jadick on mon 17 nov 97
Just read Cameron Harman's post on oxidation etc. very helpful. I am
reminded of information from a lecture by a rep of Skutt Kiln Co. Something
I never knew, black coring in reduction can be the result of a too tightly
packed electric bisque. I used to think that it only happened because of
too much body reduction. Ever since, when I bisque, I leave the lid open
and adjusted my peeps to let in more air until I am on high. What do you
think of this. I have a hood with venting fan that draws air up (the kind
that you lower over the kiln). Very high commercial electric rates cause
me to try and get a good size load in, but I don't think I over do it. Any
comments on loading and venting a bisque? Can you get carbon coring by
firing the bisque incorrectly and weaken ware that is glaze fired in an
electric kiln?
Georgia Tenore@
pjadick@worldnet.att.net
Ron Roy on thu 20 nov 97
Hi George,
Sure can - don't fire fast between 700 and 900C and make sure there is
oxygen enough to turn any CO into CO2. If you don't the CO will get the O
it needs from Fe2O3 - reducing it to FeO. FeO is a strong flux -Fe2O3 is
not. If the FeO is there it will help to overfire your body leading to
breakdown and bloating.
To see if there is O in your kiln - stick a piece of cardboard or wood in a
spyhole - if it burns inside there is O.
Can you get carbon coring by
>firing the bisque incorrectly and weaken ware that is glaze fired in an
>electric kiln?
>
>Georgia Tenore@
>pjadick@worldnet.att.net
Ron Roy
93 Pegasus Trail
Scarborough,Canada
M1G 3N8
Evenings, call 416 439 2621
Fax, 416 438 7849
Studio: 416-752-7862.
Email ronroy@astral.magic.ca
Home page http://digitalfire.com/education/people/ronroy.htm
| |
|
