Alyssa Ettinger on mon 5 mar 07
man, i wish i could find a glaze chemistry class.
ok, my main glaze is this: (and yes, i know, it does not add to 100.)
EPK Kaolin 10%
Fusion Frit F38 32%
Whiting 14%
Nepheline Syenite 26%
Flint Silica: 24
mason 1-4%
so, sage mason at 1% gives me a clear vanilla, at 4% a honesy. charcoal grey
at 1% gives me a celery. sage gray at 1% a celadon-ish,at 4% a dark fir.
this glaze is a nightmare not worth getting into. ron has worked with me and
recalculations have changed the colors, which i love. it works on my
standard porcelain body, but on my seeley's slip cast pieces crazes to the
point of embarrassment.
so, i'm changing base glazes to another feldspathic base: can't get the
celery to save my life, no matter what the mason. it's grey. can't get honey
or vanilla either. can share this recipe, but not on board, because it was
given to me by another clay-arter. if it matters, it has zinc in it. when i
use glaze without zinc it obviously doesn't flux.
i'm stumped. i hate testing. ideas?
Lee Love on tue 6 mar 07
Alyssa,
Maybe calculation is not the answer? Could you try a
Currie grid? Check out Revealing Glazes:
http://ian.currie.to/books/revealing/outline.html
--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://potters.blogspot.com/
"To affect the quality of the day, that is the highest of arts." -
Henry David Thoreau
"Let the beauty we love be what we do." - Rumi
The Goodsons on thu 8 mar 07
Dear Alyssa:
Good evening. I have done a little bit of testing with mason stains.
Here is a little bit of what I have learned about mason stains.
1. Zinc makes a huge difference, some stains are better with zinc and
some are just terrible with zinc. Use the reference codes, you can find
this list in catalogs that sell mason stains. One listing is in the
"highwater clay"catalog www.highwaterclays.com/stains/stains3.html#chart
2. The "highwater clay" catalog suggests that you try glazes that have
between 12-15% whiting for best results
If you are trying to match the colors of your original glaze, then you
want to keep some similarities for your new glaze. Since your original
recipe did not have any zinc in it, it will be important for your new
recipe to have no zinc. Also, your original glaze did have between
12-15% whiting. I think that you would need that in a new glaze as well
if you want a similar color.
A really safe recipe to try would be in MC6Glazes on page 108. It is
Ron's "Maiolica" Just leave out the zircopax, as the book recommends
when you try it with stains. I have used this recipe with mason stains
(that don't need zinc) and it worked really well. It also has the
whiting in it, similar to your original recipe.
A risky thing would be to try the following-(I love testing and playing
with INSIGHT) I took your original recipe and lowered the expansion
rate- this should help with the crazing.
F3134 12
F38 17
Whiting 14
Neph Sy 10
EPK 20
Silica 27
I have not tried it yet, so if you do, make a very small batch and see
what happens.
I don't have any F38. When I get some, I will try the risky version as
well, and let you know what I get!
Have a good evening,
Linda Goodson
Lincolnton, NC
Ivor and Olive Lewis on fri 9 mar 07
Dear Alyssa Ettinger,
You give us the following recipe and mention several commercial stains.
EPK Kaolin 10%
Fusion Frit F38 32%
Whiting 14%
Nepheline Syenite 26%
Flint Silica: 24
I would like to help you but need to know two things
a, To what temperature or cone value are you firing your work ?
b, What is your kiln atmosphere, Neutral, Reducing, or do you use a kiln =
vent?
Some stains are unstable above certain temperatures and do not give =
colours true to their colour swatches. Others deteriorate when the =
atmosphere is reducing.
By "Vanilla" do you mean brown, the colour of the pod,or pale cream, as =
though it were vanilla ice cream? Sage I know as a plant with pale weak =
blue green leaves. There could be no mix up with the labels could there =
?
| |
|
