Marcia Selsor on sat 27 jul 02
I have fired ^6 reduction for over 20 years and have achieved tenmoku,
celedons, copper reds, iron reds, etc. Usually reduce heavier for an
hour when the cone is going. Reduce lightly from ^010 for copper reds
and throw a few sticks in as it cools for a couple of hours. All the
glazes are in the archives. Michael bailey is writing a book on cone 6
reduction glazes.
Best wishes,
marcia selsor in Montana
it is raining!!!!
Jeff Longtin wrote:
>
> "no reduction firing was used for the low temperature glazes because it is
> not generally practiced to the
> same extent."
>
> The above quote caught my eye and I wonder if those more familiar might chime
> in.
>
> For years I've regretted the fact that, by and large, the majority of cone 6
> glazes do not have the same depth and richness as say cone 8 and 10 glazes. I
> thought this was so because I presumed that a reduction atmosphere is less
> effective at the lower temperatures, i.e. the metals that reduction would
> effect are not as active at the lower temperatures and hence, not affectable
> (excluding raku glazes for the moment).
>
> Am I correct in this presumption?
>
> Not too long ago it was mentioned that powdered silcon carbide could be used
> as a localized reducing agent for copper red glazes. Could it, or some other
> agent, be used in tenmoku and oil spot glazes for instance, to give them an
> added richness at cone 6?
>
> Thanks
>
> Jeff Longtin
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
--
Marcia Selsor
selsor@imt.net
http://www.imt.net/~mjbmls
http://www.imt.net/~mjbmls/Tuscany2002.html
Jeff Lawrence on sat 27 jul 02
Jeff Longtin wrote:
> For years I've regretted the fact that, by and large, the majority of cone
6
> glazes do not have the same depth and richness as say cone 8 and 10
glazes. I
> thought this was so because I presumed that a reduction atmosphere is less
> effective at the lower temperatures, i.e. the metals that reduction would
> effect are not as active at the lower temperatures and hence, not
affectable
> (excluding raku glazes for the moment).
> Am I correct in this presumption?
Hi Jeff,
Without claiming to have mastered them, I've produced in cone 6 reduction
most
of the effects associated with cone 10 reduction, such as copper reds,
celadons,
blue celadons, shinos, black temmoku, tea dust temmoku, etc. I found out
that
reducing earlier was necessary and also found that a soak at temperature and
a
slow cool-down helped glaze surfaces look better than usual. Glaze
application
matters more at lower temps, too, since there is less time for imperfections
to
heal and drips to smooth out.
There were a lot of good comments on slow firing and cooling earlier this
month,
for which I thank all who shared their experience.
I think the evidence points to oxides reacting to a reducing environment at
both
high and low temps. Personally, I managed once to over-reduce so heavily at
cone 6
that a copper red with 3% tin produced metallic tin crystals on the glaze
surface.
Tichane, a more reliable source, points out that once the glaze has sealed
over,
copper is pretty much impervious to the oxidation/reduction state of the
kiln,
hypothesizing that the reducing gases can't get past the surface easily.
My cone 6 glazes never did look as rich and finished as the cone 10 glazes
that delight mine eyes, but I suspect it was due more to my having a lot to
learn than the impossibility of getting those effects at that mid-fire
range.
Happy experimentation!
Jeff Lawrence
jml@cybermesa.com
Jeff Longtin on sat 27 jul 02
"no reduction firing was used for the low temperature glazes because it is
not generally practiced to the
same extent."
The above quote caught my eye and I wonder if those more familiar might chime
in.
For years I've regretted the fact that, by and large, the majority of cone 6
glazes do not have the same depth and richness as say cone 8 and 10 glazes. I
thought this was so because I presumed that a reduction atmosphere is less
effective at the lower temperatures, i.e. the metals that reduction would
effect are not as active at the lower temperatures and hence, not affectable
(excluding raku glazes for the moment).
Am I correct in this presumption?
Not too long ago it was mentioned that powdered silcon carbide could be used
as a localized reducing agent for copper red glazes. Could it, or some other
agent, be used in tenmoku and oil spot glazes for instance, to give them an
added richness at cone 6?
Thanks
Jeff Longtin
iandol on sun 28 jul 02
Janet Do Boos, a prominent Australian Potter and Ceramics Teacher, =
published a book of glaze recipes in 1978, She provided a range of =
glazes to cover maturing temperature from cone 07 to cone 10. From the =
first page of recipes to the last this lady included notes on results =
obtained by firing in both reduction and oxidation.
The first recipe ^07/^05 is for a fritted copper glaze mad with a =
proportion of soda ash. In oxidation this is said to be a bright clear =
turquoise and in reduction where thin to be streaked with red.
To say "no reduction firing was used for the low temperature glazes =
because it is not generally practiced to the same extent." seems a bit =
illogical or tautologous(?). Are the authors telling people they have no =
interest in this area? Rather a negative attitude.
Leaves the field wide open for the explorers and adventurous glazers.
Best regards,
Ivor Lewis. Redhill, South Australia.
| |
|
