John Post on fri 8 aug 08
Lee Love talks about how the materials we use as potters here in the
U.S. are way more refined than those he and other potters use in
Japan. How is it then that Otto can use our materials to recreate a
lost Japanese glaze?
John Post
Sterling Heights, Michigan
:: cone 6 glaze website :: http://www.johnpost.us
:: elementary art website :: http://www.wemakeart.org
Wyndham Dennison on fri 8 aug 08
>
> Date: Thu, 7 Aug 2008 16:57:07 +0000
> From: James F
> Subject: Re: Otto's yellow
>
> Wyndham...
>
> FWIW=2C I tried subbing Sr for Ba in Alfred/Woo Yellow=2C a chemically clos=
> e relative of this glaze. Went from a beautiful mustard yellow to a harsh=
> =2C nasty greenish-yellow=2C replete with typical strontium pinholes. Sr m=
> ight sit right next to Ba in the spice cabinet=2C but they sure taste diffe=
> rent. YMMV.
>
> All the best.
>
> ...James
>
>
>
>> > If this is the famous yellow=2C why not sub Strontium carb=2C somewhere
>> > around 180 Wyndham
>>
James, I'm not saying that this will work right out the box because
there are many things going on in this glaze, heat rise rate, personal
idea of what reduction is etc. But what I'm trying to encourage is
learning why something happens. In every kiln try a test, maybe there's
only 10 % strontium needed, maybe the zinc keeps other glaze ingredients
in check till the glaze gets pass a certain point.This glaze would be a
wonderful example of independent test with each person here branching
out to see what happens and 6 months from now. maybe someone will find a
great green or maybe everybody will make a crappy awful glaze and
that's great.
BTW if you calcine strontium carb it might prevent the out gassing but
it drops like a rock in a glaze so you need something to keep it in
suspension. It also may need only about 1200 deg calcine, there's
another test area. I may be in the minority on this but I love to test
and make mistakes. Some of my mistakes ended up later as production
glazes that no one would consider because it didn't follow what the book
says.Just think of the testing Otto did and if I remember correctly, I
believe I remember some healed over pin holes in the photo. Just a few
thoughts, Wyndham
| |
|
