Julie Milazzo on mon 10 jun 02
So, yesterday, I decided it was time to finally
fire again. You can't open up a gallery without pots,
and all excuses (like business license, sign permit,
warm weather) had finally exhausted themselves, so I
loaded up for my third firing of my Olympic downdraft.
So, I glazed and loaded, glazed and loaded, putting
some of the pieces from my first two firings back in,
to see if they would be happier at cone ten, rather
than thirteen, or eight. Yes, the first two firings
were disasterous, one severely overfired, one severely
underfired. Oops... anyway, though I still can't see
the cone packs after 1900 degrees F., the kiln sitter
has come in handy.
So this firing lasted ten hours, and I opened the
door this morning to find that two of the refired
pieces had blown up (damn, I knew I should have read
the posts from a few weeks back, which discussed
firing refires more slowly...), sending schrapnel and
shards into every beautiful bowl and mug (but not,
incidentally, into the bvowl that split in half, and
the ones with really ugly glaze); it's good to know
that at least the explosive pieces are finicky about
where they land. Also, some glazed pieces ran, or were
underreduced, while others were underfired and
overreduced. How did my green and red turn black and
white? Sorry, rhetorical. I do know the answer to that
one.
I think that what happened was I have collected
great recipes from a few different places, and while I
just assumed that all of these places shot for heavy
reduction, the last one had more of an oxidation
atmosphere. At Fredonia State, Marv really reduced,
and I got some great recipes from there (which will be
great if I can slow the firing and cooling, and let
them mature), but in Sonoma, we apparently kept it
pretty light. I think that my main goal is to fire
faster in the beginning, and slow up once cone six
starts to go. I won't reduce too heavily, and may have
to fire down. I had thought about that after the kiln
was off, but it was midnight, I'd had a long day,
yaddah, yaddah... oh, and I thought that I'd open the
kiln and find some decent pots. I know that I'm one
step closer every time I fire, in theory anyway, but
my first firing, the one that melted part of the kiln,
was my best.
Is there any way to get those colors and that
depth without the blisters, slumping pots, ruined
kiln, etc? The running wasn't any worse than in this
firing, believe it or not, and I think my little
kilnsitter cone actually turned off the kiln at cone
nine. Ten had just begun, so maybe if I get some small
eleven cones, my favorite glaze will go back to it's
beautiful array of rutile-induced colors and patterns,
instead of "80's-bathroom-peach". I actually kept some
of those pieces anyway, because I figured they'd be
the first to fly off the shelves. They go great with
"mother-in-law-blue". Ecchhh... any suggestions?
Thanks, Jules
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Steve Mills on wed 12 jun 02
Dear Jules,
I can't remember what size you said the kiln was, but my initial
reaction to your problems is to slow down; you'll still get the heat-
work, albeit at a slightly lower temperature, and if you start your
reduction at 1000oC (1830oF) and keep it slow and mild, the heat will
get a chance to even up through the kiln and any gasses formed in the
wares will have a chance to escape before they turn into blisters.
Personally I have never liked fast firing except in the Raku process, I
feel the pots don't have time to get *comfortable* in the glaze, a bit
like rushing out of the door with your coat half on!
Best
Steve
Bath
UK
In message , Julie Milazzo writes
> So, yesterday, I decided it was time to finally
>fire again. You can't open up a gallery without pots,
>and all excuses (like business license, sign permit,
>warm weather) had finally exhausted themselves, so I
>loaded up for my third firing of my Olympic downdraft.
>So, I glazed and loaded, glazed and loaded, putting
>some of the pieces from my first two firings back in,
>to see if they would be happier at cone ten, rather
>than thirteen, or eight. Yes, the first two firings
>were disasterous, one severely overfired, one severely
>underfired. Oops... anyway, though I still can't see
>the cone packs after 1900 degrees F., the kiln sitter
>has come in handy.
> So this firing lasted ten hours, and I opened the
>door this morning to find that two of the refired
>pieces had blown up (damn, I knew I should have read
>the posts from a few weeks back, which discussed
>firing refires more slowly...), sending schrapnel and
>shards into every beautiful bowl and mug (but not,
>incidentally, into the bvowl that split in half, and
>the ones with really ugly glaze); it's good to know
>that at least the explosive pieces are finicky about
>where they land. Also, some glazed pieces ran, or were
>underreduced, while others were underfired and
>overreduced. How did my green and red turn black and
>white? Sorry, rhetorical. I do know the answer to that
>one.
> I think that what happened was I have collected
>great recipes from a few different places, and while I
>just assumed that all of these places shot for heavy
>reduction, the last one had more of an oxidation
>atmosphere. At Fredonia State, Marv really reduced,
>and I got some great recipes from there (which will be
>great if I can slow the firing and cooling, and let
>them mature), but in Sonoma, we apparently kept it
>pretty light. I think that my main goal is to fire
>faster in the beginning, and slow up once cone six
>starts to go. I won't reduce too heavily, and may have
>to fire down. I had thought about that after the kiln
>was off, but it was midnight, I'd had a long day,
>yaddah, yaddah... oh, and I thought that I'd open the
>kiln and find some decent pots. I know that I'm one
>step closer every time I fire, in theory anyway, but
>my first firing, the one that melted part of the kiln,
>was my best.
> Is there any way to get those colors and that
>depth without the blisters, slumping pots, ruined
>kiln, etc? The running wasn't any worse than in this
>firing, believe it or not, and I think my little
>kilnsitter cone actually turned off the kiln at cone
>nine. Ten had just begun, so maybe if I get some small
>eleven cones, my favorite glaze will go back to it's
>beautiful array of rutile-induced colors and patterns,
>instead of "80's-bathroom-peach". I actually kept some
>of those pieces anyway, because I figured they'd be
>the first to fly off the shelves. They go great with
>"mother-in-law-blue". Ecchhh... any suggestions?
>Thanks, Jules
>
>__________________________________________________
>Do You Yahoo!?
>Yahoo! - Official partner of 2002 FIFA World Cup
>http://fifaworldcup.yahoo.com
--
Steve Mills
Bath
UK
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