Marley Wolhud on fri 20 mar 98
I have been firing at the local pottery place. I am unhappy with the
way they treat my things so I am going to begin firing at home. The
problem is they have a wonderful celadon glaze that comes out great in
their propane fired kiln. I will be using an electric kiln. Is there a
recipe that gives a nice traditional celadon with an electric kiln?
Jon Pettyjohn on sat 21 mar 98
Hi Marley,
unfortunately Celadon is by definition a reduction glaze, meaning
that the smoke created from cutting back the oxygen supply to a fuel
burning kiln will produce the wide range of greenish or gray green colors
called Celadon in glazes that have a small amount of Iron Oxide in them,
as little as .25 to 3% or so. The Iron could also be present in the clay
only, and the glaze could be clear and still show the typical Celadon color.
Similar (though not exactly the same) colors can be produced in
oxidation glazes by adding a small amount of Copper Oxide or
Carbonate. Around 1 to 3% of Copper Oxide or double the amount of
Copper Carbonate in a transparent or semi transparent glaze might
make a sort of "fake" Celadon in an electric kiln at cone 6 and
above. Honestly sometimes it's difficult (not impossible) to distinguish
the real thing from the "fake" oxidation version.
It might also be possible to create "real" reduction effects in an
electric kiln firing by adding small amounts of silicon carbide to
the glaze or introducing smoke or other reducing gasses somehow during the
firing. If you search the Clayart archives you might dig up some info on
this.
One of the beautiful things about Celadon is the way it colors lightly
engraved or etched decorations in the clay surface, if this is the effect
you're looking for it can certainly be produced using many kinds of colorants
in a transparent glaze. Small amounts of Copper, Cobalt or Iron will all
work well.
You didn't mention what temperature you're firing too, or the exact
shade of green in the "traditional" Celadon you want to reproduce.
There are a wide range of colors called Celadon and bear in mind
also that the type of clay you're using will have a big influence,
porcelain or stoneware for example. Maybe if you could tell us what
cone you're firing to someone could suggest a suitable base glaze
to add the colorants to.
Jon Pettyjohn
Manila
jon@mozcom.com
> ----------------------------Original message----------------------------
> I have been firing at the local pottery place. I am unhappy with the
> way they treat my things so I am going to begin firing at home. The
> problem is they have a wonderful celadon glaze that comes out great in
> their propane fired kiln. I will be using an electric kiln. Is there a
> recipe that gives a nice traditional celadon with an electric kiln?
>
Karen Gringhuis on sat 21 mar 98
Marley - how 'bout a "nice celadon for today"?? If you can flex your
definition & eye, IMHO & experience, you can get some lovely results
w/ 1% copper carb. in oxidation. I like & riends respond to
Chappell's Opaque White Satin Matt from his big book w/ 1%
Cucarb. If you can't find the book or the recipe, I can post it
AFTER NCECA. Take any glossy base you like & TEST TEST TEST.
Final advice - do NOT waste time pining away for reduction if
you're firing electric. There's a world of electric COLOR just
waiting for you.
DIANA PANCIOLI, ASSOC. PROF. on sun 22 mar 98
Marley:
We make a fake celadon at cone 04 with Batz maiolica and small amounts of
grey and green stains.
Diana
EMU
On Sat, 21 Mar 1998, Karen Gringhuis wrote:
> ----------------------------Original message----------------------------
> Marley - how 'bout a "nice celadon for today"?? If you can flex your
> definition & eye, IMHO & experience, you can get some lovely results
> w/ 1% copper carb. in oxidation. I like & riends respond to
> Chappell's Opaque White Satin Matt from his big book w/ 1%
> Cucarb. If you can't find the book or the recipe, I can post it
> AFTER NCECA. Take any glossy base you like & TEST TEST TEST.
> Final advice - do NOT waste time pining away for reduction if
> you're firing electric. There's a world of electric COLOR just
> waiting for you.
>
Dwiggins, Sandra on wed 25 mar 98
Marley--
I posted a ^6 Celadon to the list a few years ago. It's in the glaze database
under Faux Celadon. It works, colorwise, but it's a bit tricky to use.
Sometimes it crazes, depending on the clay. It looks great on porcelain.
Sandy
| |
|
