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beginners questions--about glaze ingredients

updated fri 3 nov 00

 

gretchm@BANET.NET on tue 31 oct 00


gretchm@banet.net wrote:

> First I just want to say this---- July 2, 1999 was my last day in the
> work force of the U.S. Postal Service. I retired after 30 years with
> the idea that now I was going to do pottery. I subscribed to this list
> and have met such wonderful and giving people. Thank you all for
> being who you are. Sometimes the stress of the everyday makes you
> think that we only meet other than nice people. My post is about a
> couple of ingredients that I have, that I inherited. One of them is
> from B.F.Drakenfeld & Co. - Fat Oil A-1078 . Also I have Umber.
> I have never seen it as a glaze ingredient. Could anyone tell me how
> they would be used?

One more question -- I burn wood for heat
> during the winter with various hard woods. To use as a glaze
> ingredient, how fine should it be? And also what tool [sifter] would
> be best? My thought was that I would buy a yard of the right mesh and
> stretch it on a 2X4 frame. Any suggestions would be
> appreciated. tia
> Best to all.
> Gretchen Morton in Valhalla, N.Y. about 20 mins north of N.Y.C.


Geralyn W. Barry on wed 1 nov 00


Hi Gretchen (and list),

Fat oil (aka fat oil of turpentine) is used as a medium or as one of the
components in an oil-based medium for china painting. You buy dry pigments
in little vials, grind them by hand with an oil- or water-based medium and
fire at *very* low temperatures (cone 014-020, depending on the pigments).
The oil is used to hold the pigment together until the piece is fired. Here
is a definition of fat oil from an article on china painting oils and
mediums at http://www.porcelainpainters.com/mediums.htm

"Also known as Dresden thick oil, French Fat Oil, and Thick Oil. Fat oil of
turpentine is made by evaporating pure spirits of turpentine until it is a
thick amber oil. Fat oil is one of the oldest and most commonly used media
for china painting. It is used for mixing colors and thinned with
turpentine or other media for painting."

At that same website are various recipes for mediums using fat oil.

I sometimes do many china paint (and/or luster) applications and firings to
my hand-built pieces after they have been reduction fired to cone 10. You
have more control over colors and fine details with china paints than with
glazes. Traditional china painters buy white china (called "blanks") and
paint on it. Needless to say, I do not consider myself a traditional china
painter...

Umber is a brown or reddish pigment that can be used in oil painting or
watercolor painting (no fire!) or china painting. It contains oxides of
iron and manganese. See description of raw and burnt umber at
http://www.sanders-studios.com/tutorial/historyanddefinitions/pigmentspresent.html
Not good stuff to breathe, since it contains manganese.

Drakenfeld is today called Cerdec. They used to deal in china painting
supplies, among other things. They now make pigments for many purposes,
including ceramic and glass colorants - see their website
at http://www.cerdec.com/companyinfo/drakhistory.html They probably
don't sell fat oil anymore.

Geralyn Wood Barry in rainy Wren, Oregon - making my first post to the list
gbarry@proaxis.com

At 03:47 PM 10/31/00 -0800, gretchm@banet.net wrote:
>gretchm@banet.net wrote:
>
> > My post is about a couple of ingredients that I have, that I
> inherited. One of them is
> > from B.F.Drakenfeld & Co. - Fat Oil A-1078 . Also I have Umber.
> > I have never seen it as a glaze ingredient. Could anyone tell me how
> > they would be used?
> > Best to all.
> > Gretchen Morton in Valhalla, N.Y. about 20 mins north of N.Y.C.