mel jacobson on mon 21 may 07
being a long time high school teacher gives me a reasonable
history about school glazes and bottles of glaze loaded with
very bad chemicals.
in the fifties and sixties most schools, ours included, bought
glazes...even flesh tone...(for white kids only). i can clearly remember
asking other teachers the question....`what in the hell is in that crap?`
i even wrote an article for the minneapolis tribune about the danger
to teachers and artists using lead in glaze. i was much more concerned
about teachers ingesting that stuff. kids come and go, teachers use it
for 30 years. it all landed on deaf ears.
that was about the time i decided to focus more and more on clay...to
teach an entire class ceramics. it just exploded with popularity. soon
i was teaching six classes a day. and wound up for the last twenty years
teaching full time clay.
no program could stand the cost of bottle glazes with that many students
glazing hundreds of pots each. so.....i looked into home made glazes for
my kids. bulk glaze...and a standard glaze just for my department. i had
to do something. i landed on the basic behrens` idea of volcanic ash and
gertsley borate. just two ingredients...simple...volcanic ash came in a
60 lb bag, gertsley was in a 40 lb bag...so i used 60/40 and it worked
just great at cone 4. added some zircopax...and any oxide for color.
bingo...a fifty gallon bucket in the middle of the room with a canoe paddle
in the bucket...(IT WAS ALWAYS GETTING STIRRED). we moved the
base glaze to 5 gallon pails....colored each differently...and changed them
every week. always a new adventure.
but, the best news...kids could figure out what glaze was...glass coating.
they then learned to make their own `secret formula`.
the glaze was safe, easy to make, a great learning tool and it took a huge
financial burden off my department. the fifty gallons cost 20 bucks. water
was free.
after i retired, they went back to bottled glazes. of course, what else?
home made glaze could be dangerous. hmmmm, now that is really a hoot.
they use lead based glazes and thought mine was dangerous...silly fools
with silly science. but, all you have to do is order from a catalog. ready
to go...the easy way is often the hardest way, and a terrible decision.
mel
from: mel/minnetonka.mn.usa
website: http://www.visi.com/~melpots/
Clayart page link: http://www.visi.com/~melpots/clayart.html
John Rodgers on tue 22 may 07
Mel said > "it all landed on deaf ears"
Wow, have I heard that before.
Anyway - Mel - the Behrens 60/40 volcanic ash/ gerstley borate glaze -
what amount or percentage zircopax would you recommend as a good middle
of the road amount to add? I have some volcanic ash I collected in
Alaska years ago from three different volcanoes that erupted near my
home when I was there - Mt. Augustine, Mt. Redoubt, and Mt. Spur. The
stuff will be interesting to to play with.
Thanks,
John Rodgers
Chelsea, AL
mel jacobson wrote:
> being a long time high school teacher gives me a reasonable
> history about school glazes and bottles of glaze loaded with
> very bad chemicals.
>
> in the fifties and sixties most schools, ours included, bought
> glazes...even flesh tone...(for white kids only). i can clearly remember
> asking other teachers the question....`what in the hell is in that crap?`
>
> i even wrote an article for the minneapolis tribune about the danger
> to teachers and artists using lead in glaze. i was much more concerned
> about teachers ingesting that stuff. kids come and go, teachers use it
> for 30 years. it all landed on deaf ears.
>
> that was about the time i decided to focus more and more on clay...to
> teach an entire class ceramics. it just exploded with popularity. soon
> i was teaching six classes a day. and wound up for the last twenty years
> teaching full time clay.
>
> no program could stand the cost of bottle glazes with that many students
> glazing hundreds of pots each. so.....i looked into home made glazes for
> my kids. bulk glaze...and a standard glaze just for my department. i
> had
> to do something. i landed on the basic behrens` idea of volcanic ash and
> gertsley borate. just two ingredients...simple...volcanic ash came in a
> 60 lb bag, gertsley was in a 40 lb bag...so i used 60/40 and it worked
> just great at cone 4. added some zircopax...and any oxide for color.
> bingo...a fifty gallon bucket in the middle of the room with a canoe
> paddle
> in the bucket...(IT WAS ALWAYS GETTING STIRRED). we moved the
> base glaze to 5 gallon pails....colored each differently...and changed
> them
> every week. always a new adventure.
>
> but, the best news...kids could figure out what glaze was...glass
> coating.
> they then learned to make their own `secret formula`.
>
> the glaze was safe, easy to make, a great learning tool and it took a
> huge
> financial burden off my department. the fifty gallons cost 20 bucks.
> water
> was free.
>
> after i retired, they went back to bottled glazes. of course, what else?
> home made glaze could be dangerous. hmmmm, now that is really a hoot.
> they use lead based glazes and thought mine was dangerous...silly fools
> with silly science. but, all you have to do is order from a catalog.
> ready
> to go...the easy way is often the hardest way, and a terrible decision.
> mel
>
>
>
> from: mel/minnetonka.mn.usa
> website: http://www.visi.com/~melpots/
>
> Clayart page link: http://www.visi.com/~melpots/clayart.html
>
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>
>
Sean Burns on sat 26 may 07
mel wrote:>
to do something. i landed on the basic behrens` idea of volcanic ash and
>gertsley borate. just two ingredients...simple...volcanic ash came in a
>60 lb bag, gertsley was in a 40 lb bag...so i used 60/40 and it worked
>just great at cone 4. added some zircopax...and any oxide for color.
>bingo...a fifty gallon bucket in the middle of the room.
Hi Mel,
I worked a simple base glaze in 5 gal. buckets at my school
that I had students color with the usual oxides for several years. While
this was effective I kept running into the kids telling me they wanted
flashy glazes, bright glazes, red glazes etc. That led me to delve into
mixing more complicated glazes which means more materials and time- some
of theirs but mostly mine.
I like the simplicity of the Behrens 40/60 and am going to give
it a whirl next year as a way for kids to really get the idea of what a
glaze is- that does get lost when it is just me and the advanced kids
mixing up the buckets. What I want to know is some of the tricks you may
have used to jazz it up- and is that the only glaze you used at your
school?- did students want to try other mixes- get some of those flashy
effects found in a bottle they may have used or seen elsewhere?
regards,
Sean Burns
Williamsburg, Ma.
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