Chris Schafale on tue 25 jan 00
Hi folks --
Somewhat inadvertantly, I find myself teaching a small class on
glaze mixing and development. At our first meeting on Saturday,
the question arose as to whether it is necessary to dry mix the
ingredients before adding to water. My own procedure has been to
measure each ingredient and add it directly to the water, let it
slake, mix, then add the next ingredient, etc. I sieve my glazes at
least twice through an 80 mesh screen after mixing.
I'd be interested in hearing others' opinions about the reasons for
dry mixing, and, if you think it's important, how you do it without
stirring up too much dust.
Chris
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net
www.angelfire.com/nc2/candle (work in progress)
June Perry on wed 26 jan 00
Chris:
I've never dry mixed my glazes. I just put my dry materials in a bucket add
water mix well with my turbo or jiffy mixer and put through the screen twice.
Regards,
June
Pottery by Dai on wed 26 jan 00
Hi, Chris - I dry mix to disperse the clumping-hard-to-mix chemicals
throughout the easier-to-mix ones, thus making the eventual stirring,
seiving, etc of the wet glaze a little easier. I use a large kitchen whisk
for the dry mixing---very, very slowly, so as not to stir up excess dust.
I've found it doesn't have to be thoroughly mixed, just enough to mix up the
ingredients somewhat. And, of course, I wear a mask :)
Dai in Kelowna, where about 50-60 quail come to our hedge daily to feast on
the sunflower seeds we scatter under the trees. May have to take out a
second mortgage to keep the little beggars fat and happy through the winter!
What a sight---they're really cute to watch as they traipse about the
yard(often at top speed) with their little "bobble" on their head!
-----Original Message-----
From: Chris Schafale
To: CLAYART@LSV.UKY.EDU
Date: Tuesday, January 25, 2000 4:18 PM
Subject: glazes -- why dry mix
----------------------------Original message----------------------------
Hi folks --
Somewhat inadvertantly, I find myself teaching a small class on
glaze mixing and development. At our first meeting on Saturday,
the question arose as to whether it is necessary to dry mix the
ingredients before adding to water. My own procedure has been to
measure each ingredient and add it directly to the water, let it
slake, mix, then add the next ingredient, etc. I sieve my glazes at
least twice through an 80 mesh screen after mixing.
I'd be interested in hearing others' opinions about the reasons for
dry mixing, and, if you think it's important, how you do it without
stirring up too much dust.
Chris
Light One Candle Pottery
Fuquay-Varina, NC
candle@intrex.net
www.angelfire.com/nc2/candle (work in progress)
Evan Dresel on wed 26 jan 00
I dry mix for a few reasons. I find I raise less dust dry mixing
because I do it by putting a lid on a bucket of the dry ingredients and
rolling it around for a bit. Then I let it sit until the dust settles
before opening the lid. Scooping most of the powder gently into the
water raises less dust than pouring each bit. The last little bit that
I have to pour seems to raise the most dust but by dry mixing I only
have to do that once.
I weigh most of the ingredients into one bucket anyway. Just keep
adding one on top of the other. I suppose this makes some of the
weighing error additive but I don't think that's significant. It is
easier to screw up but I'm careful. I add each ingredient into a pile
so if I go a bit overboard I can remove only the last compound added.
This could be more difficult if you are mixing bigger batches and does
depend on having a balance with sufficient range and accuracy (mine is
10 kg to the gram -- not quite enough for a 10 kg batch because of the
container weight and the added colourants).
I think the dry mixing makes the wet mixing easier. You don't have to
make up a batch of bentonite slurry first. The dry bentonite doesn't
glob up in a dry mixed batch.
-- Evan in gray West Richland WA where our few inches of snow
disappeared quickly. Hope you folks in the eastern US are having fun!
Chris Schafale wrote:
>
> ----------------------------Original message----------------------------
> Hi folks --
>
> Somewhat inadvertantly, I find myself teaching a small class on
> glaze mixing and development. At our first meeting on Saturday,
> the question arose as to whether it is necessary to dry mix the
> ingredients before adding to water. My own procedure has been to
> measure each ingredient and add it directly to the water, let it
> slake, mix, then add the next ingredient, etc. I sieve my glazes at
> least twice through an 80 mesh screen after mixing.
>
> I'd be interested in hearing others' opinions about the reasons for
> dry mixing, and, if you think it's important, how you do it without
> stirring up too much dust.
>
> Chris
> Light One Candle Pottery
> Fuquay-Varina, NC
> candle@intrex.net
> www.angelfire.com/nc2/candle (work in progress)
Earl Brunner on wed 26 jan 00
I never bother, if I'm adding bentonite I dry stir it in some before adding
water, but thats it.
Chris Schafale wrote:
> ----------------------------Original message----------------------------
> Hi folks --
>
> Somewhat inadvertantly, I find myself teaching a small class on
> glaze mixing and development. At our first meeting on Saturday,
> the question arose as to whether it is necessary to dry mix the
> ingredients before adding to water. My own procedure has been to
> measure each ingredient and add it directly to the water, let it
> slake, mix, then add the next ingredient, etc. I sieve my glazes at
> least twice through an 80 mesh screen after mixing.
>
> I'd be interested in hearing others' opinions about the reasons for
> dry mixing, and, if you think it's important, how you do it without
> stirring up too much dust.
>
> Chris
> Light One Candle Pottery
> Fuquay-Varina, NC
> candle@intrex.net
> www.angelfire.com/nc2/candle (work in progress)
--
Earl Brunner
http://coyote.accessnv.com/bruec
mailto:bruec@anv.net
Paul Lewing on wed 26 jan 00
Hi, Chris.
I dry-mix my glazes when they call for bentonite, but not if they don't.
If they don't I just do what you do and toss each ingredient into the
water as I weigh it out.
The reason I dry-mix glazes with bentonite in them is because of the way
bentonite works to do what it does. It's a flocculant, which means that
when it comes in contact with water, it forms gooey globs. If it goes
in by itself, the globs consist of bentonite only and are a slimy mess
that will never mix with the rest of your glaze slop. But if the tiny
particles of bentonite are right next to particles of other stuff, when
it hits the water, the bentonite traps all the other stuff in the globs
(floccules) which then sort of stack up in the bucket and never fall to
the bottom. So if you see a glaze recipe that calls for bentonite, you
know it would probably sink into a hard mass without it. But it only
works if the bentonite is dry-mixed in.
To dry-mix a glaze, I put it into a dry container with a tight fitting
lid, add all the powders, put the lid on, and shake rattle and roll the
container. Then I let it sit for a bit to settle the dust, then open it
up and add it to the water. Batches larger than 1000 grams I strain
twice through 80 mesh screen. Smaller batches I mix in a blender.
Have fun with the glaze class.
Paul Lewing, Seattle
NakedClay@aol.com on wed 26 jan 00
Hi Chris!
I dry mix all of my glaze recipes. This way, the ingredients can be
thouroughly mixed, the "lumps" can be grated out, and the coloring oxides
will blend better this way.
I have used the vent fan in a spray booth, to dry-mix ingredients. Also, I
wear protective clothing and a face mask, to prevent inhaling toxic
substances. I mix and seive the ingredients, after carefully measuring them,
with a 60 or 100 mesh strainer. A large plastic bowl is used to catch the
strained mixture. Sometimes I use an old paintbrush, or a spatula to seive
the materials. The "stones," or hardened materials that don't pass through
the strainer, get discarded. Sometimes I pass the mixture through a finer
strainer, a second time, to get rid of further impurities.
Once the straining is complete, the mixture is ready for water. Slowly add
water, and keep stirring with a spatula, until you reach the desired
consistency. Once water is added, it's really difficult for additional
ingredients to be added, and blended well.
So, to answer your question, I recommend that the ingredients be mixed
dry--I've done it your way once, but I was disappointed with the results :( .
Note that the best way to add ingredients to a "wet" glaze, is to let the
entire batch of glaze dry, then pulverize it. Once the glaze is in a
pulverized state, and has been "rough-screened," it's time to add the
additional ingredients. Mix the old and new, then seive together through a
60-mesh screen. Then slowly add water, as I described, above.
Best wishes!
Milton NakedClay@AOL.COM
Vince Pitelka on thu 27 jan 00
>I've never dry mixed my glazes. I just put my dry materials in a bucket add
>water mix well with my turbo or jiffy mixer and put through the screen twice.
I second what June Perry says. In thirty years I have never dry mixed a
glaze. I blend them thoroughly with a jiffy-mixer, let them sit overnight,
and blend them thoroughly them again before using. I don't even screen them
unless there is a troublesome material that will not break down without
screening.
- Vince
Vince Pitelka
Home - vpitelka@DeKalb.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
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