Hank Murrow on tue 31 oct 00
Michael Sowers wrote;
>This is a two-part question, after reading a post on ClayArt I went online
>and purchased Nigel Woods book on Chinese glazes. Can't remember who made
>the post but thank you. I am enjoying the book
>1. Has anyone tried making a glaze by just adding whiting, wollastonite, or
>washed wood ash to the clay body, up to 40%
>2. Does anyone have the chemical formula for Laguna's Rod's Bod and Takamori
>Thanks
Good Evening Michael;
Ii was one of several who posted this book reference since getting
it last January. I am mining hydrothermally altered rhyolites along the
pacific range which make nice C/8-10 porcelain bodies. They have 6-7%
KNaCaMg, 10% Al, and the rest SiO2; and vitrify anywhere from C/8 to C/11,
depending upon how much alteration took place and how much iron is present.
I have a couple of pics I can send off-list if you are interested, one
white, the other dark. Both are just as they were dug, processed and
prepared for throwing; and one is glazed with a beautiful celadon, which
was the body + wollastonite and talc. the other is fired nude in the
anagama.
David Stannard of Fairbanks, AK has been finding such deposits of
natural petuntse along the Pacific Rim for many years now, and I am
fortunate to benefit from his work. he was inspired both by his experience
growing up in Ling Po, China (using gorgeous wares since birth) and reading
the seminal work by Nigel Wood in '78. He has been to a porcelain
conference in Jingdezhen and walked into the petuntse mine there, from
which came so many sterling celadon glazed wares. they too, used the
petuntse with a limestone addition to make celadons.
Following his lead, I went up to British Columbia to dig an
unaltered rhyolite there which makes a capital blue celadon with only 5%
each of wollastonite and talc. The altered rhyolites will take up to 20%
limestone. Even well-washed wood ash will cause problems with already
problematic throwing quality, so try it with little expectation. BTW, a
useful material in the SW is Plastic Vitrox, which is an altered rhyolite
which I use sometimes in a porcelain body. Most western porcelains are too
Alumina-rich to work the way you imagine, but those based upon the Chinese
model are perfect made this way. Good Hunting! Hank in Eugene
Michael Sowers on tue 31 oct 00
This is a two-part question, after reading a post on ClayArt I went online
and purchased Nigel Woods book on Chinese glazes. Can't remember who made
the post but thank you. I am enjoying the book
1. Has anyone tried making a glaze by just adding whiting, wollastonite, or
washed wood ash to the clay body, up to 40%
2. Does anyone have the chemical formula for Laguna's Rod's Bod and Takamori
Thanks
Michael Sowers
www.classiclines.org
www.classiclinespottery.com
Michael Sowers on wed 1 nov 00
Thanks for your reply; I am just getting interested in this area. I like the
simplification of the process. Using the same body for throwing and as the
glaze base. I wanted to see what the chemical structure of some commercially
prepared clay was but Laguna refused (proprietary info). I guess I could
send some to a lab for analysis to get the AL and SiO2 ratios. I haven't
really gotten into digging my own at this point but I am interested in
seeing what you have done. If you could send me the pics I would appreciate
it.
Thanks again.
Michael Sowers
www.classiclines.org
www.classiclinespottery.com
-----Original Message-----
From: Ceramic Arts Discussion List [mailto:CLAYART@LSV.CERAMICS.ORG]On
Behalf Of Hank Murrow
Sent: Tuesday, October 31, 2000 3:02 PM
To: CLAYART@LSV.CERAMICS.ORG
Subject: Re: Nigel Woods, glazes, south china method
Michael Sowers wrote;
>This is a two-part question, after reading a post on ClayArt I went online
>and purchased Nigel Woods book on Chinese glazes. Can't remember who made
>the post but thank you. I am enjoying the book
>1. Has anyone tried making a glaze by just adding whiting, wollastonite, or
>washed wood ash to the clay body, up to 40%
>2. Does anyone have the chemical formula for Laguna's Rod's Bod and
Takamori
>Thanks
Good Evening Michael;
Ii was one of several who posted this book reference since getting
it last January. I am mining hydrothermally altered rhyolites along the
pacific range which make nice C/8-10 porcelain bodies. They have 6-7%
KNaCaMg, 10% Al, and the rest SiO2; and vitrify anywhere from C/8 to C/11,
depending upon how much alteration took place and how much iron is present.
I have a couple of pics I can send off-list if you are interested, one
white, the other dark. Both are just as they were dug, processed and
prepared for throwing; and one is glazed with a beautiful celadon, which
was the body + wollastonite and talc. the other is fired nude in the
anagama.
David Stannard of Fairbanks, AK has been finding such deposits of
natural petuntse along the Pacific Rim for many years now, and I am
fortunate to benefit from his work. he was inspired both by his experience
growing up in Ling Po, China (using gorgeous wares since birth) and reading
the seminal work by Nigel Wood in '78. He has been to a porcelain
conference in Jingdezhen and walked into the petuntse mine there, from
which came so many sterling celadon glazed wares. they too, used the
petuntse with a limestone addition to make celadons.
Following his lead, I went up to British Columbia to dig an
unaltered rhyolite there which makes a capital blue celadon with only 5%
each of wollastonite and talc. The altered rhyolites will take up to 20%
limestone. Even well-washed wood ash will cause problems with already
problematic throwing quality, so try it with little expectation. BTW, a
useful material in the SW is Plastic Vitrox, which is an altered rhyolite
which I use sometimes in a porcelain body. Most western porcelains are too
Alumina-rich to work the way you imagine, but those based upon the Chinese
model are perfect made this way. Good Hunting! Hank in Eugene
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