Denise King on tue 29 sep 98
hey ho clay puppies. i got a question about mid range firings. I need some
sugestions on how to keep my form from bowing in on itself during bisques. any
suggestions? thanks Denise King Uof F wooo hooo go gators.
Earl Brunner on wed 30 sep 98
Denise, you need to give a whole lot more information before most of us could
answer the question. Get as specific as you can. What temp. (cone) are you
firing to, reduction, oxidation? What clay are you using? What is exactly the
nature of the problem you are experiencing, on what kind of forms? That was
unclear to me. We can't see the problem so it has to be discribed in detail.
Good Luck
Earl Brunner
Cindy on fri 2 oct 98
Denise,
What sort of form are you using? I've never had a problem with this, though
I throw quite thinly, and I bisque to ^04 regularly. The only time I've
noticed trouble with pots changing shape in bisque firing is with
bowls/cups/etc. which have been accidentally warped, then re-rounded during
the wet to near leather-hard phase of drying. If you warp them, the rule
seems to be, they are warped. They may dry round, but the bisque firing
will tell the true story. Otherwise, no problems in bisque. If you could be
a little more specific . . . ?
Cindy Strnad
Earthen Vessels
Custer, SD
USA http://blackhills-info.com/a/cindys/menu.htm
Edouard Bastarache on sat 3 oct 98
Hello Cindt,
maybe it is "clay memory" that makes re-rounded bowls/cups
become warped again at the bisque stage.
Edouard Bastarache
edouardb@sorel-tracy.qc.ca
http://www.sorel-tracy.qc.ca/~edouardb/
----------
> De : Cindy
> A : CLAYART@LSV.UKY.EDU
> Objet : Re: firing help
> Date : 2 octobre, 1998 13:38
>
> ----------------------------Original message----------------------------
> Denise,
>
> What sort of form are you using? I've never had a problem with this,
though
> I throw quite thinly, and I bisque to ^04 regularly. The only time I've
> noticed trouble with pots changing shape in bisque firing is with
> bowls/cups/etc. which have been accidentally warped, then re-rounded
during
> the wet to near leather-hard phase of drying. If you warp them, the rule
> seems to be, they are warped. They may dry round, but the bisque firing
> will tell the true story. Otherwise, no problems in bisque. If you could
be
> a little more specific . . . ?
>
> Cindy Strnad
> Earthen Vessels
> Custer, SD
> USA http://blackhills-info.com/a/cindys/menu.htm
Hannah Brehmer on sun 1 nov 98
First-time user here: I just built an up-draft gas kiln and did my first =
glaze
firing. It's small - 2'x2'x2 l/2' - with four venturi burners in the =
bottom.
It fired very unevenly - cone 10 flat on the bottom, cone 6 barely starting =
on
top. Any suggestions?? My shelves are l0=22x20=22. I'm at a high =
elevation: 6200'
at Lake Tahoe, if that matters. Hope somebody can help?=21=21 Hannah
RedIron Studios on mon 2 nov 98
A couple things I could help you with from my experiance firing an Olympic
Updraft.
1) The baffle shelf (The shelf smaller than all the others that will have a
1.5" - 2.0"
gap between it and the exit flue (hole on the top ;) If your kiln does not have
one
then it will still work just be somewhat more inefficent at temperature rise. I
never
fired my old kiln without the baffle shelf. This could be one of the factors.
2) You must ensure adequate flow along the sides of the shelves and up through
the
middle.
3) This I find is the number one problem with people firing for the first time.
If it was
a reduction firing I bet you were supplying far more gas than was required. This
can
lead to the problem you were having. So watch your back pressure (i.e I'm sure
you
are controlling reduction by bricking the exit flue over) and the amount of gas
you are
supplying to the kiln.
Cheers,
RedIron Studios
-----Original Message-----
From: Hannah Brehmer
To: CLAYART@LSV.UKY.EDU
Date: Sunday, November 01, 1998 8:17 AM
Subject: firing help
>----------------------------Original message----------------------------
>First-time user here: I just built an up-draft gas kiln and did my first glaze
>firing. It's small - 2'x2'x2 l/2' - with four venturi burners in the bottom.
>It fired very unevenly - cone 10 flat on the bottom, cone 6 barely starting on
>top. Any suggestions?? My shelves are l0"x20". I'm at a high elevation:
6200'
>at Lake Tahoe, if that matters. Hope somebody can help?!! Hannah
>
Mike Gordon on mon 2 nov 98
Hi Hannah,
I may be wrong but 4 venturies in a kiln that small seems like overkill,
can you fire it with 2 maybe? slow it down to let the temp even out.
Mike in Walnut Creek, got snow yet?
Hannah Brehmer on tue 3 nov 98
Thanks, friend, for responding to my call for help. What you say rings
true. I'll put shelves close to the flue - but I wonder how close? Then I
won't turn the gas up as high so that the temp. rise is slower. If I don't
happen to hear from you again, I think I'll have those top shelves about 4"
below the opening. Thanks again. Hannah
-----Original Message-----
From: RedIron Studios
To: CLAYART@LSV.UKY.EDU
Date: Monday, November 02, 1998 9:31 AM
Subject: Re: firing help
>----------------------------Original message----------------------------
>A couple things I could help you with from my experiance firing an Olympic
>Updraft.
>
>1) The baffle shelf (The shelf smaller than all the others that will have a
>1.5" - 2.0"
>gap between it and the exit flue (hole on the top ;) If your kiln does not
have
>one
>then it will still work just be somewhat more inefficent at temperature
rise. I
>never
>fired my old kiln without the baffle shelf. This could be one of the
factors.
>
>2) You must ensure adequate flow along the sides of the shelves and up
through
>the
>middle.
>
>3) This I find is the number one problem with people firing for the first
time.
>If it was
>a reduction firing I bet you were supplying far more gas than was required.
This
>can
>lead to the problem you were having. So watch your back pressure (i.e I'm
sure
>you
>are controlling reduction by bricking the exit flue over) and the amount of
gas
>you are
>supplying to the kiln.
>
>Cheers,
>RedIron Studios
>
>
>
>-----Original Message-----
>From: Hannah Brehmer
>To: CLAYART@LSV.UKY.EDU
>Date: Sunday, November 01, 1998 8:17 AM
>Subject: firing help
>
>
>>----------------------------Original message----------------------------
>>First-time user here: I just built an up-draft gas kiln and did my first
glaze
>>firing. It's small - 2'x2'x2 l/2' - with four venturi burners in the
bottom.
>>It fired very unevenly - cone 10 flat on the bottom, cone 6 barely
starting on
>>top. Any suggestions?? My shelves are l0"x20". I'm at a high elevation:
>6200'
>>at Lake Tahoe, if that matters. Hope somebody can help?!! Hannah
>>
>
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