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comment on overfired bisque experience

updated mon 13 feb 06

 

Randy McCall on sat 11 feb 06


I had a kiln load overfire in electric, yes left it unattended-real time
lesson.
Tried to save it by going ahead and glazing it. Took three afternoons to
apply the glazes because it took so long for the glazes to dry. Used a
commerical glaze as it adhered better to overfire bisque clay. Took extra
time to let glaze dry. Also fired extra slowly.

Really wasted my time with it.

When I opened the kiln after the glaze fire the glaze had popped off on the
inside of the bean pots I had made in small places. Outsides were ok. Only
a few pieces made it through.

Keep learning something everyday. Maybe this will help someone in the
future.

Randy

Pottery Web Site
members.tripod.com/~McCallJ/index.html
South Carolina

Donna Kat on sun 12 feb 06


On Sat, 11 Feb 2006 11:05:30 -0500, Randy McCall wrote:

>I had a kiln load overfire in electric, yes left it unattended-real time
>lesson.
>Tried to save it by going ahead and glazing it. Took three afternoons to
>apply the glazes because it took so long for the glazes to dry. Used a
>commerical glaze as it adhered better to overfire bisque clay. Took extra
>time to let glaze dry. Also fired extra slowly.
>
>Really wasted my time with it.
>
>When I opened the kiln after the glaze fire the glaze had popped off on the
>inside of the bean pots I had made in small places. Outsides were ok. Only
>a few pieces made it through.
>
>Keep learning something everyday. Maybe this will help someone in the
>future.
>
>Randy


We had a serious overfired bisqued (we don't know what it went to but it it
was hot enough that the 112 had gone buff brown in color - this was for a
cone 6 firing). Weathered bronze green worked fine on it as did a clear
glaze we had (I would have to check on the recipe). Heating up the pot
before glazing helped to get the glaze thick enough. Some use corn syrup on
the pot before glazing in a case like this. Pinnell's bronze green seems to
be an extremely forgiving glaze. It can fire from cone5 even though it was
originally made for I believe cone 9.

Bate's Clear,
Clear,
Glossy,
6,
,
,
Works nicely over other glazes,
,
Feldspar--Kona F4 ,3500,
Flint ,2200,
Gerstley Borate--1999 ,1800,
Kaolin--EPK ,1000,
Strontium Carbonate ,800,
Whiting ,800,

pikeur69 on sun 12 feb 06


Thank you, Rany for this post!

I have asked a lot of questions to the community lately about why my
glazes don't behave and why they don't dry on my bisque ware. I
mentioned that I overfired the glaze load of the kiln t=E1nd that's the
reason the glazes came out all wrong. But OF COURSE I also overfired
the bisque kiln because it has the same computer! So my bisque was
overfired and the glaze pooled, came off and behaved bad in general.
Now at least I know what to deal with...

Theresa




>
> I had a kiln load overfire in electric, yes left it unattended-real time
> lesson.
> Tried to save it by going ahead and glazing it. Took three
afternoons to
> apply the glazes because it took so long for the glazes to dry...
> When I opened the kiln after the glaze fire the glaze had popped off
on the
> inside of the bean pots I had made in small places. Outsides were
ok. Only
> a few pieces made it through.
>
> Keep learning something everyday. Maybe this will help someone in the
> future.
>
> Randy
>
> Pottery Web Site
> members.tripod.com/~McCallJ/index.html
> South Carolina
>
>
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