Ann Brink on thu 29 may 03
Lynne, I looked up lepidolite in Rhodes' "Clay & Glazes for the Potter" and
he says:
"Lepidolite (HO2F)2KLiAl2Si3O10) is a lithium mica and is sometimes used as
a source of lithium in glazes. It has a lower fusion point than most
feldspars, and the lithia will serve to make most glazes more shiny than
when a potash or soda spar is used.Lepidolite, however, seems to cause
boiling and pitting in some glazes".
Hope this is of some help. Maybe someone else will have a recipe, or more
direct experience for you.
Ann Brink, Lompoc CA
----- Original Message -----
From: "Lynne Burke"
To:
Sent: Thursday, May 29, 2003 5:34 PM
Subject: Chemical Expiration?
> I have recently received a gift of a myriad of chemicals from a private
> school which is no longer mixing its own glazes. I was told that many of
> these chemicals may be over 10 years old! My question is, is there a
shelf
> life/expiration for most chemicals? Are any notoriously short-lived?
>
> Among the chemicals was a container of lepedolite--probably about 25 lbs.
I
> searched the archives and was unable to locate any glaze recipes
containing
> this chemical. Anybody out there have recipes they would share? Or, does
> anyone have a recipe they loved but have been unable to use because of the
> unavailabilty of lepedolite--if so, I will be delighted to send it to you.
>
> Thanks in advance for all help!
>
> Lynne
>
> visit our website at www.potteryabroad.com
>
> .
Fredrick Paget on thu 29 may 03
>Most ceramic chemicals don't go bad with age. Many of them if not
>most are ground up minerals that are already millions of years old.
Perhaps some like CMC may go bad but that is a man made organic
chemical and is susceptible to caking if it gets moist.
> My question is, is there a shelf
>life/expiration for most chemicals? Are any notoriously short-lived?
--
From Fred Paget, Marin County, California, USA
G.M. Schauer on thu 29 may 03
Retry a Google search for 'lepidolite glaze' (your spelling is wrong.) It
is a high lithium feldspar, and there are a number of references to its uses
in glazes.
Galen Schauer
Minnesota
----- Original Message -----
From: "Lynne Burke"
To:
Sent: Thursday, May 29, 2003 7:34 PM
Subject: Chemical Expiration?
> I have recently received a gift of a myriad of chemicals from a private
> school which is no longer mixing its own glazes. I was told that many of
> these chemicals may be over 10 years old! My question is, is there a
shelf
> life/expiration for most chemicals? Are any notoriously short-lived?
>
> Among the chemicals was a container of lepedolite--probably about 25 lbs.
I
> searched the archives and was unable to locate any glaze recipes
containing
> this chemical. Anybody out there have recipes they would share? Or, does
> anyone have a recipe they loved but have been unable to use because of the
> unavailabilty of lepedolite--if so, I will be delighted to send it to you.
>
> Thanks in advance for all help!
>
> Lynne
>
> visit our website at www.potteryabroad.com
>
> _________________________________________________________________
> Tired of spam? Get advanced junk mail protection with MSN 8.
> http://join.msn.com/?page=features/junkmail
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>
____________________________________________________________________________
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> Send postings to clayart@lsv.ceramics.org
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>
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>
>
Louis Katz on thu 29 may 03
Red Copper Oxide eventually turns black.
Manganese carbonate eventually seems to turn to the dioxide.
Some materials pick up water. Not much changes much though.
Lepidolite, petalite and Spodumene are Lithium Alumina Silicates.
Some materials become more expensive; Albany, gertsley. Others become
unavailable; Avery Kaolin, Michigan Slip.
Some other materials become junk. My last batch of Missouri Fireclay
for example.
Try my rewritten old glaze calculator online at:
http://falcon.tamucc.edu/~lkatz/gc1/input.htm
On Thursday, May 29, 2003, at 07:34 PM, Lynne Burke wrote:
> I have recently received a gift of a myriad of chemicals from a private
> school which is no longer mixing its own glazes. I was told that many
> of
> these chemicals may be over 10 years old! My question is, is there a
> shelf
> life/expiration for most chemicals? Are any notoriously short-lived?
>
> Among the chemicals was a container of lepedolite--probably about 25
> lbs. I
> searched the archives and was unable to locate any glaze recipes
> containing
> this chemical. Anybody out there have recipes they would share? Or,
> does
> anyone have a recipe they loved but have been unable to use because of
> the
> unavailabilty of lepedolite--if so, I will be delighted to send it to
> you.
>
> Thanks in advance for all help!
>
> Lynne
>
> visit our website at www.potteryabroad.com
>
> _________________________________________________________________
> Tired of spam? Get advanced junk mail protection with MSN 8.
> http://join.msn.com/?page=features/junkmail
>
> _______________________________________________________________________
> _______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
>
Lynne Burke on thu 29 may 03
I have recently received a gift of a myriad of chemicals from a private
school which is no longer mixing its own glazes. I was told that many of
these chemicals may be over 10 years old! My question is, is there a shelf
life/expiration for most chemicals? Are any notoriously short-lived?
Among the chemicals was a container of lepedolite--probably about 25 lbs. I
searched the archives and was unable to locate any glaze recipes containing
this chemical. Anybody out there have recipes they would share? Or, does
anyone have a recipe they loved but have been unable to use because of the
unavailabilty of lepedolite--if so, I will be delighted to send it to you.
Thanks in advance for all help!
Lynne
visit our website at www.potteryabroad.com
_________________________________________________________________
Tired of spam? Get advanced junk mail protection with MSN 8.
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