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artificial reduction glazes

updated wed 27 jul 11

 

Larry Nakanishi on mon 25 jul 11


Thank you all for sharing your experiences. Still in the process of settin=
g
up our glaze area and the next couple of firing will be for an up coming
festival. Hope to do some trials toward the end of August and will report
if anything interesting happens.

The book has been checked out from the OVCAG library but I will look to
purchase a used one. Amazon is asking $177.00 + for a new book...
Currently learning about glaze and function of various materials. Long way
to travel but this seems to fit into the journey.

Thanks again!
Larry


On Mon, Jul 25, 2011 at 6:48 PM, Steve Slatin wrote=
:

> I was doing this last summer, then went and did some
> quite different things and didn't get back to it.
>
> I could get quite good reduction results (bright
> 'reduction' toned reds with only 0.2 % copper
> as a colorant and 0.9 percent tin as an opacifier/
> brightener) using silicon carbide 0.15 percent to
> provide the reduction. (SC comes in different grades;
> I found the "FFF" grade to give the best results.)
>
> I also found that you could brush a pattern of SC
> onto a pot, glaze with the copper glaze without
> any of the SC in it, and it'd give a slightly blotchy
> pattern of red within the green. With this, interestingly,
> I found the coarser grades more effective.
>
> Problems -- I couldn't get it to work with most of
> my better copper green glazes; the glazes where it
> worked were generally runny, and it required a thick
> application to go red. It doesn't stay in the slurry
> at all well, you have to re-mix often or it all ends
> up at the bottom of the bucket and your 'red' pot
> will be green. Still, an interesting idea.
>
>
> Steve Slatin --
>
> N48.0886450
> W123.1420482
>
>
> --- On Mon, 7/25/11, Larry Nakanishi wrote:
>
> > Currently reading a book "Glazes for
> > Special Effects" by Herbert H. Sanders.
> > Using silicon carbide, aluminum carbide and perhaps boron
> > carbide in a
> > glaze using copper carbonate will result in copper reds
> > when fired in
> > oxidation to cone 10 - 11. Has any one tried using
> > this artificial
> > reduction on any glaze? If so, what type of clay body
> > and glaze used and
> > what were the results? I will probably begin to
> > experiment in the next
> > month or two and just looking for a beginning point.
> >
> > Thank you all for contributing to the knowledge of
> > beginners.
> >
> > Larry
> >
>

Larry Nakanishi on mon 25 jul 11


Currently reading a book "Glazes for Special Effects" by Herbert H. Sanders=
.
Using silicon carbide, aluminum carbide and perhaps boron carbide in a
glaze using copper carbonate will result in copper reds when fired in
oxidation to cone 10 - 11. Has any one tried using this artificial
reduction on any glaze? If so, what type of clay body and glaze used and
what were the results? I will probably begin to experiment in the next
month or two and just looking for a beginning point.

Thank you all for contributing to the knowledge of beginners.

Larry

William & Susan Schran User on mon 25 jul 11


On 7/25/11 4:39 PM, "Larry Nakanishi" wrote:

> Currently reading a book "Glazes for Special Effects" by Herbert H. Sande=
rs.
> Using silicon carbide, aluminum carbide and perhaps boron carbide in a
> glaze using copper carbonate will result in copper reds when fired in
> oxidation to cone 10 - 11. Has any one tried using this artificial
> reduction on any glaze? If so, what type of clay body and glaze used and
> what were the results? I will probably begin to experiment in the next
> month or two and just looking for a beginning point.

Have had the book since it was published and ran some tests with artificial
reduction copper reds. I think one thing that will contribute to better
results is using a very fine silicon carbide, at least FFF grade.
All my tests were dark muddy reds, but that was 30 years ago.

Bill

--
William "Bill" Schran
wschran@cox.net
wschran@nvcc.edu
http://www.creativecreekartisans.com

Steve Slatin on mon 25 jul 11


I was doing this last summer, then went and did some
quite different things and didn't get back to it.

I could get quite good reduction results (bright
'reduction' toned reds with only 0.2 % copper=3D20
as a colorant and 0.9 percent tin as an opacifier/
brightener) using silicon carbide 0.15 percent to
provide the reduction. (SC comes in different grades;
I found the "FFF" grade to give the best results.)

I also found that you could brush a pattern of SC
onto a pot, glaze with the copper glaze without
any of the SC in it, and it'd give a slightly blotchy
pattern of red within the green. With this, interestingly,
I found the coarser grades more effective.

Problems -- I couldn't get it to work with most of
my better copper green glazes; the glazes where it
worked were generally runny, and it required a thick
application to go red. It doesn't stay in the slurry
at all well, you have to re-mix often or it all ends
up at the bottom of the bucket and your 'red' pot
will be green. Still, an interesting idea.


Steve Slatin --=3D20

N48.0886450
W123.1420482


--- On Mon, 7/25/11, Larry Nakanishi wrote:

> Currently reading a book "Glazes for
> Special Effects" by Herbert H. Sanders.
> Using silicon carbide, aluminum carbide and perhaps boron
> carbide in a
> glaze using copper carbonate will result in copper reds
> when fired in
> oxidation to cone 10 - 11.=3DA0 Has any one tried using
> this artificial
> reduction on any glaze?=3DA0 If so, what type of clay body
> and glaze used and
> what were the results?=3DA0 I will probably begin to
> experiment in the next
> month or two and just looking for a beginning point.
>=3D20
> Thank you all for contributing to=3DA0 the knowledge of
> beginners.
>=3D20
> Larry
>

Paul Lewing on tue 26 jul 11


On Jul 25, 2011, at 1:39 PM, Larry Nakanishi wrote:

Has any one tried using this artificial
reduction on any glaze?

I tried it a few years back with a cone 5 oxidation copper glaze. I
found that to get it to turn red, I had to fire it to at least cone
7. And the SC from the ceramic supply store wasn't nearly fine
enough. I had some 800 mesh and 1000 mesh stuff that was made for
polishing stuff and that sort of worked. My conclusion was that if you
wanted reduction, you should do reduction. If you were doing
oxidation, you should stick with what oxidation does well.

Paul Lewing
www.paullewingtile.com
www.paullewingart.com