Loren JOnes on wed 4 nov 09
I am wondering if someone could shed some light on reduction. I fired last =
weekend and thought I was getting good reduction but had a rather odd resul=
t. The interiors of a few bowls that I had glazed with celadon were that li=
ght yellow color we all hate to get. But oddly enough the insides of the fo=
ot ring were nicely reduced. One would think that the glazes that had direc=
t contact with the flamey reduction atmosphere would stand a better chance =
of reducing rather than the bottom of the bowl that has no direct contact. =
I don't have the use of an oxy-probe so I go by flame appearance and the "=
murky" look of the interior of the kiln. Anyone...?
http://www.lojoclayworks.com
Randall Moody on wed 4 nov 09
On Wed, Nov 4, 2009 at 11:03 AM, Loren JOnes wrote:
> I am wondering if someone could shed some light on reduction. I fired las=
t
> weekend and thought I was getting good reduction but had a rather odd
> result. The interiors of a few bowls that I had glazed with celadon were
> that light yellow color we all hate to get. But oddly enough the insides =
of
> the foot ring were nicely reduced. One would think that the glazes that h=
ad
> direct contact with the flamey reduction atmosphere would stand a better
> chance of reducing rather than the bottom of the bowl that has no direct
> contact. I don't have the use of an oxy-probe so I go by flame appearanc=
e
> and the "murky" look of the interior of the kiln. Anyone...?
> http://www.lojoclayworks.com
>
My guess is that the small area of the foot ring sets up its own little kil=
n
like atmosphere. If the seal, for want of a better term is good between the
foot ring and the shelf the oxygen in that area can become more depleted
than the rest of the kiln leading to a reduction atmosphere in that area.
--
Randall in Atlanta
Michael McDowell on thu 5 nov 09
Loren,
You got one response suggesting that there might be a little different
atmosphere inside the foot ring of your celedon glazed bowls. That may be,
but it may also be that it is a little cooler there at the time you start
reduction. You might have started reduction just a little too late to get
proper celedon formation on the bowls. There is no going back for those
bowls, but next time you fire celedon you might try just a little earlier
reduction.
Michael McDowell
Whatcom County, WA, USA
michael@mcdowellpottery.com
http://www.McDowellPottery.com
Ron Roy on fri 6 nov 09
Hi Loren,
I tend to agree with Michael - if the clay becomes too tight it will not
take reduction properly - or if the glaze seals over before the reduction i=
s
started - the clay that is covered with glaze will not get reduced.
The other reason it may have happened - after a successful body reduction -
if you slip back into oxidation the body can become reoxidized. So staying
in reduction till the clay seals over enough to stay reduced is the answer
in that case.
Breaking the pot may be the clue you need to diagnose the problem - if the
clay is reduced inside the it is the second case. If not reduced at all
under the glaze then look to Micheal's solution.
On Wed, Nov 4, 2009 at 11:03 AM, Loren JOnes wrote:
> I am wondering if someone could shed some light on reduction. I fired las=
t
> weekend and thought I was getting good reduction but had a rather odd
> result. The interiors of a few bowls that I had glazed with celadon were
> that light yellow color we all hate to get. But oddly enough the insides =
of
> the foot ring were nicely reduced. One would think that the glazes that h=
ad
> direct contact with the flamey reduction atmosphere would stand a better
> chance of reducing rather than the bottom of the bowl that has no direct
> contact. I don't have the use of an oxy-probe so I go by flame appearanc=
e
> and the "murky" look of the interior of the kiln. Anyone...?
> http://www.lojoclayworks.com
>
--
Ron Roy
15084 Little Lake Road
Brighton, Ontario, Canada
K0K 1H0
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