clifton wood on tue 8 apr 03
well, i'm taking a glaze materials class...
and one assignment was to look at every material in the glaze pantry & figure out why
it's there.
so i made an inventory list & settled in with hamer & rhodes.
then i googled things i couldn't find.
but still... there are some things i don't even have a 1st grade understanding of why
they are there.
any help would be appreciated.
and are there other places i should have checked first?
thanks,
sabra wood
*antimony oxide
far as i can tell, this is an opacifier, but inferior to tin & zircon, both of
which we have. it's used for naples yellow stain with lead, but we don't have
lead. so why do we have this?
*barium sulfate
we don't have barium carbonate or barium oxide. but we do have barium sulfate. why
would we only stock the soluble form?
*boric acid
my reading says this is a neutral oxide (what's that mean?) which functions more as
a flux. says it lowers expansion & increases elasticity of glaze. also increases
gloss. but i can't find anyone who uses it. silly me, i initially thought it was
there as an eye wash!
we also have boric oxide, which people do seem to use to correct crazing & intensigy
colors.
*copper sulfate
books say it's a metallic salt used in red & gold lustres. but no one in studio
uses it.
*frit 5303
can't find any mention of it anywhere. could it be a typo for 5301?
*potassium carbonate
i read that it's soluble & rarely used in glazes... find in frits as source of
potassium. so why do we have it?
*pumice
cleaning hands, cleaning raku were my 1st thoughts. local studio residents say it
was used in hi phenom glazes in the 70s but is now thought to be ineffective,
yielding not very nice grey bubbled surfaces?
*soda bicarbonate
reading says it's sometimes used as a substitute for salt in salt firings & reduces
pollution by chlorine vapors. but we don't do salt firings.
*sodium nitrate
is this the same as soda nitre, which also seems to have the quaint name of chile
saltpetre? Reading says it's highly soluble sodium salt used in fritting. and that
it's too expensive to use in sodium oxide.
*strontium carbonate
reading says this is prepared from celsite. and that it has same effect as whiting,
but is more expensive. so why would one use it instead of whiting?
*tungstic acid
all i could find out is that it's from scheelite. big whoop. how it it used?
*vamullite
can't find out anything about this. someone in studio wondered if it was a trade
name for mullite? we don't have mullite.
*yellow ochre
reading says this is limonite. a soft, crumbly variety of iron ore - a bog ore.
useful in clay & glaze colorant. but when would you use it instead yellow iron
oxide?
Ababi on wed 9 apr 03
Hello Sabra
What does your teacher wants from your life?
Or... When did she last time read or studied?
I will follow your questions with my answer:
>*antimony oxide
> far as i can tell, this is an opacifier, but inferior to tin & zircon, both of
>which we have. it's used for naples yellow stain with lead, but we don't have
>lead. so why do we have this?
try this:http://www.digitalfire.ab.ca/cermat/index.php write antimony:
>*barium sulfate
> we don't have barium carbonate or barium oxide. but we do have barium
sulfate. why
>would we only stock the soluble form?
Yes the same wondering. I think you teacher lives in the past.
>*boric acid
Boric acid is the simplest source of B2O3 sometimes when you cannot have another
source when
you need a huge amount of B2O3 you might use it- might be with bad result.
>
> we also have boric oxide, which people do seem to use to correct crazing &
intensigy
>colors. Boric oxide is B2O3 It is part of borax and frits and Gerstly Borate!
The oxide is the smallest size of most minerals we use.
>*copper sulfate
> books say it's a metallic salt used in red & gold lustres. but no one in studio
>uses it.
I bought some but do not use it, it is a soluble material poisonous through the skin,
can give you beautiful effects in raku.
>*frit 5303
I can't find any mention of it anywhere. could it be a typo for 5301?
It is not in the link I gave you, must be a historic frit: Ask your teacher where you can
buy it.
>*potassium carbonate
> i read that it's soluble & rarely used in glazes... find in frits as source of
>potassium. so why do we have it?
Change your teacher. I dumped some K2O lately because it was useless
>*pumice The ash of the volacano eroption.
You better buy the Magic Of Fire from Tony Hansen and or Clay and Glazes for the
potter, not the exact name by Rhodes revised by Hopper might be some misspellings
but the right book. Hamer and hamer dictionary is a dictionary. You are not learning a
new language with a dictionary. The Hamer book will help you to understand deeper
the language latter on!
>*soda bicarbonate
I had it in a glaze was terrible to use, you may use it either as a backing soda or
use to avoid chemical weapon if you cannot find a mask!
> reading says it's sometimes used as a substitute for salt in salt firings &
reduces
>pollution by chlorine vapors. but we don't do salt firings.
Yes but is that what you do know?
*sodium nitrate
is this the same as soda nitre, which also seems to have the quaint name of
chile
saltpetre? Reading says it's highly soluble sodium salt used in fritting. and that
it's too expensive to use in sodium oxide.
>*strontium carbonate
> reading says this is prepared from celsite. and that it has same effect as
whiting,
>but is more expensive. so why would one use it instead of whiting?
This time I am your teacher best friend, See the first link I had given you.
>*tungstic acid
> all i could find out is that it's from scheelite. big whoop. how it it used?
I know they use it for making strong steel drills
This time I am your teacher best friend, See the first link I had given you
*vamullite
VERMICULITE
*yellow ochre
reading says this is limonite. a soft, crumbly variety of iron ore - a bog ore.
useful in clay & glaze colorant. but when would you use it instead yellow iron
oxide?
READ the right books learn from a good teacher!
Ababi Sharon
Glaze addict
Kibbutz Shoval Israel
About paperclay :
http://members4.clubphoto.com/ababi306910/803792/
Similar in Hebrew
http://members4.clubphoto.com/ababi306910/839502/
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