Opinion - Bisque Firing Cone 06 or 04

"Andrew Werby" wrote in message
...

"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has suggested
firing to cone 04 to help eliminate various glaze problems. Any opinions
on
this?

[We were having pinholing problems in low-fire ware (not just Gerstly
Borate
glazes). Firing the bisque to a maturity as high or higher than the glaze
helped eliminate the holes. I think these clays contain something volatile
that outgasses at peak temperatures, and makes its way out through the
molten glaze. On the other hand, the body was marginally less absorbant of
glaze, if that's an issue.]

Andrew Werby
www.computersculpture.com



I bisque to con 06, well I guess its 06 I hardly ever do a cone reading on a
bisque (I know I should) but I always soak for 30 minutes at temp. So I set
the kiln for 1000C, (1830F) and soak for 30 minutes. When I did not soak
so long I was having problems with pin holing. I also soak my glaze firing
for 30 minutes. I do use cones for my glaze firing, so have to take into
account the soak. I think though that the soaking ensures that the glaze
has time to mature and any volatile substances have time to escape.

"walamalacalucy" wrote in message
m...
"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has suggested
firing to cone 04 to help eliminate various glaze problems. Any opinions
on
this?

04 fires it to maturity (or should if your kiln reaches the proper
temp.) for best results the bisque firing should be done 2 cones
higher than the glaze firing. the extra time and cost is minimal but
the result is a whole lot better, eliminating some of the blips that
can happen otherwise.

Oh I disagree, it would mean that it would not be porous anymore and
applying glaze then becomes a difficulty. I prefer dip glazing where
possible. I have no problems with pin holing since doing a soak with both
bisque and glaze. I have few glaze problems actually other than if I have
applied it too thick, too thin, or it is a new glaze I am testing and just
didn't work )

"annemarie" wrote in message
...

"walamalacalucy" wrote in message
m...
"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has
suggested
firing to cone 04 to help eliminate various glaze problems. Any
opinions
on
this?

04 fires it to maturity (or should if your kiln reaches the proper
temp.) for best results the bisque firing should be done 2 cones
higher than the glaze firing. the extra time and cost is minimal but
the result is a whole lot better, eliminating some of the blips that
can happen otherwise.

Oh I disagree, it would mean that it would not be porous anymore and
applying glaze then becomes a difficulty. I prefer dip glazing where
possible. I have no problems with pin holing since doing a soak with both
bisque and glaze. I have few glaze problems actually other than if I have
applied it too thick, too thin, or it is a new glaze I am testing and just
didn't work )

How long do you do your soak on the bisque? We glaze fire to cone 6 and I
am trying to bully the administrator into letting us do ramp firings on
those but we are at a University and in today's new world everything is done
with an eye to 'making a profit' - don't get me started... It had never
occurred to me to soak the bisque to get rid of the LOI. I also dip glaze
but I have never really adjusted to the difference in humidity between the
west and east cost so I really do like the pots to be porous.

"jedi" wrote in message
...

"annemarie" wrote in message
...

"walamalacalucy" wrote in message
m...
"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has
suggested
firing to cone 04 to help eliminate various glaze problems. Any
opinions
on
this?

04 fires it to maturity (or should if your kiln reaches the proper
temp.) for best results the bisque firing should be done 2 cones
higher than the glaze firing. the extra time and cost is minimal but
the result is a whole lot better, eliminating some of the blips that
can happen otherwise.

Oh I disagree, it would mean that it would not be porous anymore and
applying glaze then becomes a difficulty. I prefer dip glazing where
possible. I have no problems with pin holing since doing a soak with
both
bisque and glaze. I have few glaze problems actually other than if I
have
applied it too thick, too thin, or it is a new glaze I am testing and
just
didn't work )

How long do you do your soak on the bisque? We glaze fire to cone 6 and I
am trying to bully the administrator into letting us do ramp firings on
those but we are at a University and in today's new world everything is
done
with an eye to 'making a profit' - don't get me started... It had never
occurred to me to soak the bisque to get rid of the LOI. I also dip glaze
but I have never really adjusted to the difference in humidity between the
west and east cost so I really do like the pots to be porous.


Always soak for 30 minutes. Thats my rule now )

"annemarie" wrote in message
...

"jedi" wrote in message
...

"annemarie" wrote in message
...

"walamalacalucy" wrote in message
m...
"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has
suggested
firing to cone 04 to help eliminate various glaze problems. Any
opinions
on
this?

04 fires it to maturity (or should if your kiln reaches the proper
temp.) for best results the bisque firing should be done 2 cones
higher than the glaze firing. the extra time and cost is minimal but
the result is a whole lot better, eliminating some of the blips that
can happen otherwise.

Oh I disagree, it would mean that it would not be porous anymore and
applying glaze then becomes a difficulty. I prefer dip glazing where
possible. I have no problems with pin holing since doing a soak with
both
bisque and glaze. I have few glaze problems actually other than if I
have
applied it too thick, too thin, or it is a new glaze I am testing and
just
didn't work )

How long do you do your soak on the bisque? We glaze fire to cone 6 and
I
am trying to bully the administrator into letting us do ramp firings on
those but we are at a University and in today's new world everything is
done
with an eye to 'making a profit' - don't get me started... It had never
occurred to me to soak the bisque to get rid of the LOI. I also dip
glaze
but I have never really adjusted to the difference in humidity between
the
west and east cost so I really do like the pots to be porous.


Always soak for 30 minutes. Thats my rule now )

Thanks, I will do this at home. I can't imagine how I'm going to get it
past the administrator on campus given that they bulked at a 10 min soak for
the glaze fire (Have I complained about bureaucrats here? - I try to limit
my rants..... ). I'm a bit worried about over firing and I do a ramp firing
on the glaze with a 15min soak... how much heat work do you think you get
with that long of soak... a half cone?

Dear Jedi,

There is another way around this; slow the firing ramp down in the final
sector, firing temperature curves always slow naturally - just
accentuate it a bit. I don't soak at all; I just fire slower and it
works really well as a technique at both Earthenware and Stoneware
temps.

Steve
Bath
UK


In article , jedi
writes


Thanks, I will do this at home. I can't imagine how I'm going to get it
past the administrator on campus given that they bulked at a 10 min soak for
the glaze fire (Have I complained about bureaucrats here? - I try to limit
my rants..... ). I'm a bit worried about over firing and I do a ramp firing
on the glaze with a 15min soak... how much heat work do you think you get
with that long of soak... a half cone?



--
Steve Mills
Bath
UK

"DKat" wrote in message ...
We have always bisque fired to cone 06. One of the potters has suggested
firing to cone 04 to help eliminate various glaze problems. Any opinions on
this?

thankyou for your reply, but i answered your query with the info you
gave.firing to c4 and c6 ( which you stated in your answer to me is
what you fire to !!!)is on a completely different scale to your query
which was about 04 and 06. hope you put all the other good people
who were kind enough to answer you in the picture.

"walamalacalucy" wrote in message
m...
"DKat" wrote in message
...
We have always bisque fired to cone 06. One of the potters has
suggested
firing to cone 04 to help eliminate various glaze problems. Any
opinions on
this?

thankyou for your reply, but i answered your query with the info you
gave.firing to c4 and c6 ( which you stated in your answer to me is
what you fire to !!!)is on a completely different scale to your query
which was about 04 and 06. hope you put all the other good people
who were kind enough to answer you in the picture.

We seem to have some confusion here. The question was in regards to a
BISQUE firing which we do at cone06. The GLAZE firing is cone6. We are
getting bubbles in one of our glazes (well three glazes but all with the
same base which uses Gerstly). This glaze has only recently been
misbehaving and I suspect it is the Gerstly which varies with each dig. One
of our potters suggested firing to a higher BISQUE to deal with the problem
in the GLAZE firing (the large case is for my benefit so that I am sure I am
making the right references... sorry but I'm verbally defective and since
whatever I posted seems to have lead to confusion I am doing the best I can
to clarify).

So far I think we are at the conclusion that raising the bisque fire does
deal with eliminating gasses in the body that may be an issue in the glaze
firing but so does soaking or a ramp firing. That yes, the issue is
probably the gerstley which we should be getting away from now that frits
are just as affordable... Soaking, ramping good, 04 bisque has mixed
results (loss of ability to suck up the glaze but sturdier bisqueware that
is safer to handle and may aid in the bubbling of glaze).... What I found
most interesting was the concept of ramping or soaking a bisque. I have
always gone with the candle forever then fire to cone. It never occurred to
me that there would be a reason to do otherwise. Now I know.