Lili Krakowski on sat 14 jan 06
Annapoorna Sitaram cannot get nepheline syenite or custer feldspar in =
India where she is.
I think it is Steve who wrote that spars are pretty interchangeable. =
Which they ARE, as witnessed by the endless number of published recipes =
that simply call for "feldspar" (The convention is that plain =
"feldspar" means potash spar, and that soda spar is specified as such.
But I became curious and looked up CULLET both in Parmelee and Cardew. =
(Cardew discusses it as "container glass".
Parmelee says cullet contains "approximately" 0.5 Na20, 0.5 CaO, Sio2. =
He also warns that it settles down quickly (something we can prevent) =
Cardew gives this Seger formula for cullet : 0.55 Na20, 0.22 CaO, =
0.22MgO, 0.01BaO, 0.04 Al2O3, 2.655 SiO2.
Obviously--and as both gents point out--cullet has too low an alumina =
content to stay on pots---but, it seems to me I'd give it a whirl could =
I not get neph., sy.
Now cullet --such a pretty word--is ground glass. And ground old glass =
is a constituent in making NEW glass--or so I have been told over and =
over again. Therefore a factory that makes glass, such as a factory =
making beer or soda bottles, possibly even one making window panes, and =
like that, should have some cullet. And I expect a small amount--like =
50 lbs--should be obtainable. Cullet, I imagine, is also used in making =
other stuff...NO IDEA...but a factory making whatever might part with =
some.....
Now then: QUESTION: In the dawn of prehistory, when studio pottery =
still was unknown in the US --i.e. before the 1950's--all of us potting =
then calcined stuff. We calcined zinc, borax, and I forgot what else. =
I would like to calcine some potassium --any idea at what temp? Do I =
need a cone, can I just heat till test kiln bright orange...or what?
Ideas?
Lili Krakowski
Be of good courage
Taylor, in Rockport TX on sat 14 jan 06
Dearest Lili and them othern what hefts a glass here in the Ram's Head,
I want you to know that I have a bag of blue cullet, the makings of which
David Hendley gave to me, sitting under my work bench. When I had access
to a ball mill at Baylor U (sigh) I turned the great blue glass bottles
David shattered for me into potential glaze material. If I can do it,
ANYBODY can. One only needs a blue-bottle-guy, a way to just get glass
bottles to slump, a bucket of water, protective gear, a ball mill, and
some spare time.
Do you know that I have probably a dozen blue bottles in my garagio
waiting to be turned into 'free' cullet. I haven't even used my original
batch yet!
I have only ever calcined EPK for some engobe trials. I just gave it some
room in a bisque (^04) firing, so I think a test kiln at orange would be
enough. Of course I've not been doing this for 40 years, so take my
advice with a grain of soda ash.
All good things,
Taylor
Ivor and Olive Lewis on mon 16 jan 06
Dear Lili Krakowski,=20
You ask << I would like to calcine some potassium --any idea at what =
temp? Do I =3D
need a cone, can I just heat till test kiln bright orange...or what?>>
Can you clarify please. Do you mean "Potassium" or do you mean "Potash" =
or do you mean "Caustic Potash" or do you mean "Pearl Ash" or do you =
mean "Potassium Felspar". I ask because all can be subject to high =
temperature but the results may or may not be of use.
Best regards,
Ivor Lewis.
Redhill,
South Australia.
Lori Doty on tue 31 jan 06
snip
> Now cullet --such a pretty word--is ground glass. And ground old
> glass is a constituent in making NEW glass--or so I have been told
> over and over again. Therefore a factory that makes glass, such as a
> factory making beer or soda bottles, possibly even one making window
> panes, and like that, should have some cullet. And I expect a small
> amount--like 50 lbs--should be obtainable. Cullet, I imagine, is also
> used in making other stuff...NO IDEA...but a factory making whatever
> might part with some.....
snip
I did a quick search on places that carry cullet and came up with this
website that
might help those who are looking for cullet without the hassle of
making it yourself. I found a reference to the Keystone Cullet company
in an older pottery book I had borrowed and they were referenced in it
about making glazes with the stuff.
The book for those interested is titled contemporary ceramic techniques
ISBN 0-13-169540-1 and authored by John W. Conrad. Mostly black and
white pictures but some color plates dispersed in the copy I have. It
features works of 100 ceramists that the author photographed all over
the US. Fascinating stuff and I haven't gotten through a third of it
yet.
Not sure if I'll try it or not but seems like a good starter to use
cullet to make a glaze.
Lori Doty
Nurse/Potter
Slowly turning the tide.
Rolla, Missouri
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