Earl Brunner on mon 17 apr 06
Oxygenated fir
So Lee, if the originals didn't have lead in the earthenware glaze, then what was the preferred flux in those glazes?
http://www.chass.utoronto.ca/~kovacevi/whatismaiolica.htm
lee love wrote:
--- In clayart@yahoogroups.com, Lili Krakowski wrote:
> maybe tin and some zirconium product, but once the lead is out, the true
> majolica look is gone.
This didn't sound right to me, so I did a little surfing. The
original Spanish and the Middle Easter Maiolica/Majolica and many of
the European and American versions, contained no lead. So, there is
no need for it to include lead to be "authentic."
A related quote, related colonial majolica:
"A clear lead glaze to which has been added tin-oxide in a proportion
of approximately 1:3. The addition of tin-oxide to the glaze created
an opaque, generally whiter surface that was often decorated with blue
and polychrome designs. The glaze, however, is fragile and easily
separates from the body. Because the tin content in the glaze was a
more expensive ingredient than the lead, some potters in England (and
presumably in Holland as well) sometimes used a lead or a greatly
thinned tin-glaze on the backs of plates, dishes, and chargers. Lead
glazes do not appear to have ever been used on the back of Spanish
majolica dishes." (Noël Hume 1977:42-43; Deagan 1987).
Deagan, Kathleen
1987 Artifacts of the Spanish Colonies of Florida and the Caribbean,
1500-1800, Volume I: Ceramics, Glassware, and Beads. Smithsonian
Institution Press, Washington, D.C.
Noël Hume, Ivor.
1967 Rhenish Gray Stonewares in Colonial America. Antiques, 2: 349-352.
--
Lee In Mashiko, Japan
http://togeika.googlepages.com/
http://seisokuro.blogspot.com/
Earl Brunner
e-mail: brunv53@yahoo.com
Lili Krakowski on mon 17 apr 06
Oxygenated firing; majolica sans lead
1. I know this is me being hateful, but, as someone who has vile luck
looking things up in the archives, I question subject lines on serious
topics which then cannot be looked up unless one gets the original joke.
Leaving aside that Bourry is a genuine surname, and people named Bourry no
doubt have heard it all, to write about Boring Boxes when giving very useful
info about them, is not being as helpful as one might want to be.
2. Being hateful (see above) I long have protested the use of the name
"majolica" for glazes which, but only to the untrained eye, look like tin
opacified, lead earthenware glazes but are not. May: there are dozens and
dozens of beautiful white glazes that will give a majolica like look. No
reason the one you found should not. I prefer to use tin as opacifier, or
maybe tin and some zirconium product, but once the lead is out, the true
majolica look is gone. "Weep no more, my lady"....just accept reality as
she is lived.
3. Those were the days! And somewhere I still have a few small bags of
stains (discarded now for toxic content) from Steward. That was the time my
studio was on Cornelia Street....With that said, they made great bodies, BUT
most of those wonderful clays are gone....gone are Jordan, Monmouth, Fetzer,
Perrine, Dalton....So I doubt any of the bodies Steward made are duplicable
(IS there such a word?) today....
4. Thank you Ivor. But a ?. How do you classify muffle kilns? They do get
auxiliary air up their pipes....I have NO idea what actually happens in the
chamber. For the youn'uns a muffle kiln was a box within a box...sometimes
a solid inner chamber with the flame roaring up and around it, other times
rows of tubes around the chamber with the flames roaring up them. I weel
recall a nice Revelation muffle kiln at SAC, which, now that I am
countrified, I realize was a regular large cast iron stove--as found as
furnace in a house, with a muffle arrangement built in.
Lili Krakowski
Be of good courage
lee love on mon 17 apr 06
Oxygenated fir
--- In clayart@yahoogroups.com, Lili Krakowski wrote:
.
>
> 4. Thank you Ivor. But a ?. How do you classify muffle kilns?
>They do get auxiliary air up their pipes....I have NO idea what
>actually happens in the chamber.
One way to find the topic you are looking for (no way to find this
bit about muffle kilns from how you titled it Lili) is to search the
body of the email and not just the title. Google is a hand way to do
this.
Hamada's enamel kiln, that he also used to bisque teabowls in at
the end of a work cycle, is a "box in a box" design. So are the
traditional charcoal fired raku kilns.
--
Lee In Mashiko, Japan
http://mashiko.org
http://seisokuro.blogspot.com/
"Really there is no East, no West,
Where then is the South and the North?
Illusion makes the world close in,
Enlightenment opens it on every side."
--Inscription inside Japanese Pligrim's Hat
lee love on tue 18 apr 06
Oxygenated fir
--- In clayart@yahoogroups.com, Earl Brunner wrote:
>
> So Lee, if the originals didn't have lead in the earthenware glaze,
>then what was the preferred flux in those glazes?
Alkaline, soda based frits, opacifide by tin. Baghdad was the center
of its development and creation.
"Glazes of the Middle East, are shiny and frequently transparent.
These glazes are composed mostly of silica (such as sand) and a form
of soda (such as nitre)."
Some more:
"Tin-glazed wares (majolica) originated in 9th century Mesopotamia,
most likely from a desire to imitate white T'ang Chinese wares.
Islamic potters created a semblance of the white surface by opacifying
their transparent alkaline glazes with tin oxide, effectively masking
the buff-colored earthenware clay body. Seduced by the white surface,
artisans began to decorate it with oxides. In time, distinctive
patterns emerged, becoming more sophisticated. The other important
development was that of the use of reduced-pigment lusters on tin
glaze in a third firing."
"In the 10th Century the Calif of Persia received a gift of over 2000
pieces of porcelain from the Emperor of China. Persian craftsmen were
amazed at the white and blue glazes. Thought they could not unravel
the secret of the Chinese glazes they were able to invent their own
techniques to duplicate the effect. The potters of Baghdad exported
their wares all across Northern Africa and many Islamic potters
migrated to Morocco and eventually Moorish Spain, bringing with them
their secret methods and formulae. Merchants based on the island
Majorca shipped so much of this pottery from Spain to Italy that it
became forever associated with the island. After the Moors were thrown
out of Spain, majolica potters set up small factories in Italy near
the mineral rich banks of the river Metauro in the towns of Deruta,
Gubbio, and Faenza where the finest clay deposits and minerals for the
glazes were to be found in abundance. In the 16th century luster
glazes similar to those used in Valencia and Talavera, Spain were
developed in Umbria as well as metallic gold and a ruby red iridescent
glazes."
--
Lee In Mashiko, Japan
http://togeika.googlepages.com/
http://seisokuro.blogspot.com/
"Love is the virtue of the heart
Sincerity the virtue of the mind
Courage the virtue of the spirit
Decision the virtue of the will."
--Frank Loyd Wright
lee love on tue 18 apr 06
Oxygenated fir
--- In clayart@yahoogroups.com, Lili Krakowski wrote:
> maybe tin and some zirconium product, but once the lead is out, the true
> majolica look is gone.
This didn't sound right to me, so I did a little surfing. The
original Spanish and the Middle Easter Maiolica/Majolica and many of
the European and American versions, contained no lead. So, there is
no need for it to include lead to be "authentic."
A related quote, related colonial majolica:
"A clear lead glaze to which has been added tin-oxide in a proportion
of approximately 1:3. The addition of tin-oxide to the glaze created
an opaque, generally whiter surface that was often decorated with blue
and polychrome designs. The glaze, however, is fragile and easily
separates from the body. Because the tin content in the glaze was a
more expensive ingredient than the lead, some potters in England (and
presumably in Holland as well) sometimes used a lead or a greatly
thinned tin-glaze on the backs of plates, dishes, and chargers. Lead
glazes do not appear to have ever been used on the back of Spanish
majolica dishes." (No=EBl Hume 1977:42-43; Deagan 1987).
Deagan, Kathleen
1987 Artifacts of the Spanish Colonies of Florida and the Caribbean,
1500-1800, Volume I: Ceramics, Glassware, and Beads. Smithsonian
Institution Press, Washington, D.C.
No=EBl Hume, Ivor.
1967 Rhenish Gray Stonewares in Colonial America. Antiques, 2: 349-352.
--
Lee In Mashiko, Japan
http://togeika.googlepages.com/
http://seisokuro.blogspot.com/
"Love is the virtue of the heart
Sincerity the virtue of the mind
Courage the virtue of the spirit
Decision the virtue of the will."
--Frank Loyd Wright
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