Lee Love on thu 8 feb 07
Hi Michael,
I use a couple different runny glazes. One is a runny
ash. My teacher dips the top of this glaze pot full str the glaze to
glaze the bottom half. Because the glaze moves so much, I thought
brushing the bottom half thinly would work as well so that is what I
have been doing and it works well.
The other thing you can do is glaze the bottom half with a
stable glaze and the top half with your runny glaze. Actually, you
can get some very nice effects with this. I do this with Nuka on top
of Tenmoku. You can see an example here:
http://public.fotki.com/togeika/pots_from_mashiko/aut_0020.html
I also do this with a runny rutile, with ruitle at the top
and a strontium glaze at the bottom.
--
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
Ron Roy on fri 9 feb 07
Hi Michael,
The problem is - alumina inhibits crystal development - ergo - all
crystalline glazes are short of alumina and run.
If you add more alumina you will probably have to cool slower to get the
same kind of results - I'm guessing here because I have no experience to
back that particular scenario up.
RR
>Thanks, Dave. I like your idea of testing some alternatives, but I
>am especially interested in the idea of a less-runny crystaline glaze.
>
>Do you, or anyone else out there, have a recipe for a low-run
>crystaline glaze? Would adding more alumina to a glaze i've worked
>with be a place to start? (I had thought that the mobility of the
>glaze allows crystals to form, but I would be willing to sacrifice
>size of crystals for a less fluid glaze.)
Ron Roy
RR#4
15084 Little Lake Road
Brighton, Ontario
Canada
K0K 1H0
Chris Groat on sun 11 feb 07
I'm very new to crystalline glazes, and ceramics for that matter, but
here's some info that might help. I was reading through one of my
crystalline glaze books, and I remembered this post. Here is a formula for
a cone 10-11 glaze that claims to be a low fluidity glaze. If you're doing
cone 6 you could try adding some lithium carb. to the formula. Maybe 5%?
Ferro frit 3134 15.45
Pemco frit P 283 39.15
Zinc Oxide 23.77
Silica 21.63
Should work well with Cu, Co, Ni, Fe, and Mn.
I often use crystaline glazes as an over-dip. No crystals grow, but it
creates some very cool effects, long drips, swirl patterns, interesting
colors, etc. When I do this, the glaze almost always flows to the bottom
of the piece, so it is necessary to have a flared foot so that the glaze
can pool at the bottom without running off onto the shelf. I suspect you
will have at least one or two drips that go all the way to the bottom of
the piece. I don't know exactly what you're trying to fire, but if it's
not flared at the bottom I would try to place it on a biscuit of 50/50 saw
dust/EPK. Or you could place the piece on a slab of clay and use a pencil
torch to crack the glaze drips and remove your sculpture from the slab.
If you end up firing twice, I think if the high fire glaze is touching the
shelf, even at low-fire temp, it might fuse to the shelf. Definitely test
first.
If you try modifying the glaze by adding Alumina, keep it below 10%. I've
had limited success with about 6% max.
Good Luck,
Chris
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