Gail Dapogny on mon 4 jun 07
Hi Dawn,
Wiser heads will give you more information, but it sure sounds like
your glaze was too thick. Malcolm uses a somewhat thin glaze
solution (never thick) and layers it here and there, also blowing on
it in places for feathering results. If you are not getting
toastiness on your body, then your early reduction is too light.
Gail Dapogny in Ann Arbor, MI
On Jun 4, 2007, at 11:16 AM, Dawn Raburn wrote:
> Well, I just opened the kiln and the shinos are white! Dang. Here's
> what I did and ya'll critique. I used Malcolm's Shino, glazed the
> Thurs before firing on Sat. Application was pretty thick...that is
> probably it. The glaze is very crawled and crazed and white with
> just barely a blush of peach where I had layered plastic wrap. Not
> at all what I wanted. Hank, I couldn't get your shino ingredients so
> I mixed what I had. I did body reduction at 012 (I'm still
> eyeballing it cause can't afford an oxyprobe yet). Then up to cone
> 10 at 14 hours (the last 20 min were oxidation) total firing time. I
> then left damper and ports open for 1 hour and then closed down to
> slow cool. I am a little worried that the damper may have had about
> an inch opening accidently. The other glazes are as follows: mattes
> are very matte, temmoku is part shiny and part sorta satin and not a
> good smooth surface (that was on a sink so the thickness and size may
> be the reason), the tomato red is nice, but the copper red test tile
> is a great celadon green! From looking at the clay body I don't
> think I got heavy reduction as they are not quite as dark as my first
> firing. So can you all deduce anything from my results? Any
> suggestions? I will try to get pictures if that would help. Thanks
> so much Hank, Larry, Ian and Lee for your input!
>
> Dawn
> in Tennessee
>
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Dawn Raburn on mon 4 jun 07
Well, I just opened the kiln and the shinos are white! Dang. Here's
what I did and ya'll critique. I used Malcolm's Shino, glazed the
Thurs before firing on Sat. Application was pretty thick...that is
probably it. The glaze is very crawled and crazed and white with
just barely a blush of peach where I had layered plastic wrap. Not
at all what I wanted. Hank, I couldn't get your shino ingredients so
I mixed what I had. I did body reduction at 012 (I'm still
eyeballing it cause can't afford an oxyprobe yet). Then up to cone
10 at 14 hours (the last 20 min were oxidation) total firing time. I
then left damper and ports open for 1 hour and then closed down to
slow cool. I am a little worried that the damper may have had about
an inch opening accidently. The other glazes are as follows: mattes
are very matte, temmoku is part shiny and part sorta satin and not a
good smooth surface (that was on a sink so the thickness and size may
be the reason), the tomato red is nice, but the copper red test tile
is a great celadon green! From looking at the clay body I don't
think I got heavy reduction as they are not quite as dark as my first
firing. So can you all deduce anything from my results? Any
suggestions? I will try to get pictures if that would help. Thanks
so much Hank, Larry, Ian and Lee for your input!
Dawn
in Tennessee
Hank Murrow on mon 4 jun 07
On Jun 4, 2007, at 8:16 AM, Dawn Raburn wrote:
> Well, I just opened the kiln and the shinos are white! Dang. Here's
> what I did and ya'll critique. I used Malcolm's Shino, glazed the
> Thurs before firing on Sat. Application was pretty thick...that is
> probably it. The glaze is very crawled and crazed and white with
> just barely a blush of peach where I had layered plastic wrap. Not
> at all what I wanted. Hank, I couldn't get your shino ingredients so
> I mixed what I had. I did body reduction at 012 (I'm still
> eyeballing it cause can't afford an oxyprobe yet). Then up to cone
> 10 at 14 hours (the last 20 min were oxidation) total firing time. I
> then left damper and ports open for 1 hour and then closed down to
> slow cool. I am a little worried that the damper may have had about
> an inch opening accidently. The other glazes are as follows: mattes
> are very matte, temmoku is part shiny and part sorta satin and not a
> good smooth surface (that was on a sink so the thickness and size may
> be the reason), the tomato red is nice, but the copper red test tile
> is a great celadon green! From looking at the clay body I don't
> think I got heavy reduction as they are not quite as dark as my first
> firing. So can you all deduce anything from my results? Any
> suggestions? I will try to get pictures if that would help. Thanks
> so much Hank, Larry, Ian and Lee for your input!
Dear Dawn;
Is your body relatively dark? Sounds like the Malcolm Shino was on
pretty thick. For Hank's Shino you don't need McNamee...........use
6_Tile instead. Neph Sye and Low Melt Spod are then all you
need..........Georgies in Portland OR can supply the Low Melt. I do
want you to have success with my glaze, so keep trying and reporting
back.
Cheers, Hank
www.murrow.biz/hank
Lee Love on tue 5 jun 07
Dawn,
You will get folks telling you all different ways to glaze and
fire shinos and carbon trap glazes. I am with Tony about not letting
the glaze sit after glazing (I know others here have said to do
exactly that.)
I don't think the soda "evaporates", but I believe the quick
drying is more likely to pull solubles out of the body into the glaze
layer.
Can you share which Davis you are using? Remember: if you
are glazing porcelain or a white stoneware, you need to use the recipe
with red art in it:
Malcolm Davis Shino
Soda Ash 17.27
Kona F-4 Feldspar 9.82
Nepheline Syenite 40.91
Edgar Plastic Kaolin 18.18
Kentucky Ball Clay (OM 4) 13.82
Cedar Heights Redart + 6.0
I had trouble getting red in shino in my kiln
here in Mashiko until I started using high alumina shinos. What gave
me this idea, was that I noticed that the reddest things in my kiln
were the high alumina stilts. I highly recommend John Britt's
High Fire Glazes. You can find firing scheduals and also high
alumina shinos there.
> be the reason), the tomato red is nice, but the copper red test tile
> is a great celadon green! From looking at the clay body I don't
> think I got heavy reduction as they are not quite as dark as my first
> firing.
The copper red gives more information about a lack of
reduction. And Tomato likes oxidation.
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
Dave Finkelnburg on tue 5 jun 07
Dear Matt,
If carbon trapping is the goal of a firing, it is
only necessary to keep the kiln in reduction until the
glaze is fully melted. Once the carbon is trapped
beneath the glass of the melted glaze, it will stay
there despite oxidation.
Most people lose the carbon by either:
1. not reducing enough to produce soot (carbon) to
trap.
2. not reducing heavily early enough so that the
carbon can be trapped, i.e. before the glaze glosses
over.
3. not keeping the kiln in reduction from the point
of producing carbon until the glaze glosses over.
The third point is most problematic. If one
reduces too heavily for too long, all the pots are so
black as to be uninteresting. To avoid this is a
dance with the kiln...reducing heavily enough, but not
too heavily...long enough, but not too long...then
backing off on reduction to prevent forming more soot
but still maintaining enough reduction to prevent
oxidizing the carbon until the glaze melts over it...
Good potting,
Dave Finkelnburg
Date: Tue, 5 Jun 2007 13:19:21 -0400
From: "MacIntire, Matt"
I'd only add that my recollection is that Malcolm not
only reduces
early, but keeps the kiln in very light reduction for
the rest of the
firing. The rationale is that if you let the kiln
oxidize fully on the
way to cone 10, whatever carbon you have trapped will
most likely burn
away.
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MacIntire, Matt on tue 5 jun 07
Gail's advice about using Malcolm's shino very thin is excellent advice.
Too think and you lose the effect. =20
I'd only add that my recollection is that Malcolm not only reduces
early, but keeps the kiln in very light reduction for the rest of the
firing. The rationale is that if you let the kiln oxidize fully on the
way to cone 10, whatever carbon you have trapped will most likely burn
away.
In addition, Malcolm's pots are very thin. Thin walls seem to help the
soda ash crystalize onto the surface rather than get sucked into the
body. =20
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