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crawling shino issue

updated sun 11 oct 09

 

Lee Love on fri 9 oct 09


On Fri, Oct 9, 2009 at 12:24 PM, wrote:
> Lee- it was listed as a Gustin recipe.=3DA0 I left out soda ash because
> unbisqued pots were falling apart with soda
>
> F-4 =3DA0 =3DA0 18.4
> Spodumene 15.2
> OM4 (ball)=3DA0 =3DA0 15
> Neph Sye =3DA0 45
> EPK =3DA0 =3DA0 =3DA0 2.4

Doesn't look like you have too much clay. I would recommend thinner
applications.
--
Lee Love, Minneapolis
"The tea ceremony bowl is the ceramic equivalent of a sonnet: a
small-scale, seemingly constricted form that challenges the artist to
go beyond mere technical virtuosity and find an approach that both
satisfies and transcends the conventions." -- Rob Sliberman
full essay: http://togeika.multiply.com/journal/item/273/

Paul Haigh on fri 9 oct 09


I have a problem with my shino crawling (unwanted) in my wood kiln. Some=
=3D

pots come out awesome- my tests were good- made up a batch. This has
happened on pots that were single fired and those that were bisqued.=3D20=
=3D20=3D


An interesting observation- the side that faces the fire seems to rarely =
=3D
if
ever have a crawling issue. Is this because of ash flux changing the gla=
=3D
ze,
or because it wants to be a higher temp before reduction (I reduce at ^01=
=3D
0)?=3D20=3D20

I suspect that some pots were not bisqued to a very high temp- like in th=
=3D
e
09-08 range. Would a ^06 bisque possibly fix this?=3D20=3D20

Thanks,
-pH
http://wileyhill.com

Lee Love on fri 9 oct 09


012 bisque works well with shino.

Share your reciped. It can give clues. Also, thick applications or
salt in the glaze will enhance chances of crawling.

--
Lee Love, Minneapolis
"The tea ceremony bowl is the ceramic equivalent of a sonnet: a
small-scale, seemingly constricted form that challenges the artist to
go beyond mere technical virtuosity and find an approach that both
satisfies and transcends the conventions." -- Rob Sliberman
full essay: http://togeika.multiply.com/journal/item/273/

Paul Haigh on fri 9 oct 09


Lee- it was listed as a Gustin recipe. I left out soda ash because unbisque=
d pots were falling apart with soda

F-4 18.4
Spodumene 15.2
OM4 (ball) 15
Neph Sye 45
EPK 2.4


----- Original Message -----
From: "Lee Love"
To: "Paul Haigh"
Cc: Clayart@lsv.ceramics.org
Sent: Friday, October 9, 2009 12:31:15 PM GMT -05:00 US/Canada Eastern
Subject: Re: Crawling shino issue

012 bisque works well with shino.

Share your reciped. It can give clues. Also, thick applications or
salt in the glaze will enhance chances of crawling.

--
Lee Love, Minneapolis
"The tea ceremony bowl is the ceramic equivalent of a sonnet: a
small-scale, seemingly constricted form that challenges the artist to
go beyond mere technical virtuosity and find an approach that both
satisfies and transcends the conventions." -- Rob Sliberman
full essay: http://togeika.multiply.com/journal/item/273/

John Britt on fri 9 oct 09


Paul,

Check the amount of clay in the recipe. (exclude the soda ash if there i=
=3D
s any)

If it is over 20 - 25% it may crawl. You could apply it thinner or calcin=
=3D
e half=3D20
the clay,

John Britt
www.johnbrittpottery.com

Edouard Bastarache on sat 10 oct 09


Hello all,

maybe some sort of temperature differential
between the 2 sides of the pot, who knows?

David is a ceramic engineer, maybe he could discuss
my hypothesis? I am stuck

Gis,

Edouard Bastarache
Spertesperantisto

Sorel-Tracy
Quebec

http://edouardbastarache.blogspot.com/
http://substitutions.blogspot.com/
http://www.flickr.com/photos/30058682@N00/
http://albertpaintings.blogspot.com/
http://cerampeintures.blogspot.com/





----- Original Message -----
From: "L TURNER"
To: ; ; ;
;
Sent: Friday, October 09, 2009 11:59 PM
Subject: Re: Crawling shino issue


> Gentlemen:
>
> Paul Haigh
> Lee Love
> John Britt
> David Finkelnburg
> Edouard Bastarache
>
> All of the replies have presented "true" information, but ss any of
> this really helping Paul with his crawling problem?
>
> Paul said:
> "An interesting observation- the side that faces the fire seems to rarely
> if
> ever have a crawling issue.".
>
> No one has addressed or explained why a pot that wants to crawl would
> only want to crawl on the side away from the fire.
>
> Using calcined clay address mainly the shrinkage of a glaze as it
> dries before it is placed in the kiln. If the absence of calcined
> clay were the cause, why would the pot only crawl away from the heat?
>
> If the problem is dust or poor adhesion why would this only occur away
> from the heat?
>
> Surface tension is a glaze composition and temperature property. So
> why is it higher on the crawling side than on the non crawling side?
>
> So far Paul has only standard answers to a problem that is not standard.
>
> Paul,
>
> I need more data.
>
> Is this a recent problem, or one that has been on and off over a long
> period (several firings)?
> When you are reducing, how do you judge that you are in reduction? Is
> the kiln smoking? Is the firebox and kiln filled with soot, or is it
> just murky red?
> Where in the kiln are the pots being placed? Are they the first thing
> the fire sees when it comes into to the ware chamber? Are other pots
> having any problems (crawling or whatever)?
> How thick is the glaze application?
> How long have the pots dried after glaze application before firing
> starts? Are they bone dry, or just without sheen?
> During the heatup of the kiln, is the kiln atmosphere moist or dry?
> Are the kiln bricks wet or dry when firing starts?
> Do you have a gas or electric kiln and have fired the shino there?
> Does it crawl there or only in the wood kiln?
> With some of this information perhaps we can think of some
> "non-standard" possibilities for why the glaze crawling.
>
> What is the temperature profile during the firing? How much hotter is
> the pot on the fire side than on the cool side?
>
>
>
> Regards,
> L. Turner
> The Woodlands, Tx
>