vince pitelka on thu 7 nov 02
Ron Mitton wrote"
"This is frequently brought up on Clayart ie.to "dry mix" ingredients before
adding to water. In my experience there does not appear to be any
difference as long as in "wet mixing" excess water and a blunger or whirler
are used. Would anyone like to present their "proof "to clayart that dry
mixing is necessary?"
Ron -
I don't recall anyone saying that dry mixing is necessary with claybodies,
but I may have missed that. There are certainly times when dry mixing is
advantageous. When mixing claybodies using the blunging method to make a
thick slurry. If you add the materials one at a time, then you have to
stick with your original estimation in terms of the raw materials amounts,
adding the appropriate amounts of each material until all are added. If you
end up with a slurry that is too thin, it takes a lot longer to stiffen it
to plastic consistency, and you cannot mound it up for quick stiffening. On
the other hand, if you premix the dry materials, you can simply keep adding
the dry mix until your slurry is the appropriate thickness, and then mound
it up in rows on an appropriate surface, and pretty soon you have plastic
clay.
Also, when mixing clay from recycle slurry in a mechanical claymixer, you
need to add dry materials to stiffen the slurry. Doing that by adding small
amounts of all the raw materials would be very inefficient. Instead, with a
batch of dry-mixed claybody, you can simply add the mix until the clay is
the appropriate consistency.
As simple as it is to dry mix, this is not any big thing. As has been said
numerous times on Clayart, dry mixing only requires a heavy cardboard
shipping drum with the appropriate lid and clamp band. Fasten several
lengths of 2x2 lumber up either side of the inside of the barrel with
drywall screws driven through from the outside. Put all your dry materials
in the barrel, clamp on the lid, tip it over, and roll it around the room
for a minute or two, and you have thoroughly dry-mixed claybody.
Regarding glazes, I've been in ceramics for over thirty years, and I have
never dry mixed a glaze. I can't see any advantage to that.
Best wishes -
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
David Beumee on thu 7 nov 02
Dear Ron,
I think it is particularly important to put all the ingredients for a celedon glaze in a plastic bag,
leave some air and seal the bag, then mix thoroughly by rolling the bag around on the floor. The small
amount of iron is dispersed well, important in a celedon glaze. Also, if an accident occurs while pouring
the dry ingredients into water, I know that some important ingredient hasn't been left out. Sometimes
adding 99% pure red iron oxide or macaloid directly to water is a problem, a little like trying to get oil and
water to mix in the case of pure red iron oxide, and mixing all the dry ingredients together eliminates this
problem. I mix all my glazes dry inside a bag. I just get a better feeling about the glaze being a
homogenous whole before it slakes down in the water.
David Beumee
Earth Alchemy Pottery
Lafayette, Colodado
11/7/02 1:45:35 PM, Jean Mitton wrote:
>This is frequently brought up on Clayart ie.to "dry mix" ingredients before adding to water.
> In my experience there does not appear to be any difference as long as in "wet mixing" excess
water and a blunger or whirler are used.
> Would anyone like to present their "proof "to clayart that dry mixing is necessary?
>
> RON MITTON
> SOUTH AFRICA
>
>______________________________________________________________________________
>Send postings to clayart@lsv.ceramics.org
>
>You may look at the archives for the list or change your subscription
>settings from http://www.ceramics.org/clayart/
>
>Moderator of the list is Mel Jacobson who may be reached at melpots@pclink.com.
>
Jean Mitton on thu 7 nov 02
This is frequently brought up on Clayart ie.to "dry mix" ingredients =
before adding to water.
In my experience there does not appear to be any difference as long =
as in "wet mixing" excess water and a blunger or whirler are used.
Would anyone like to present their "proof "to clayart that dry =
mixing is necessary?
=20
RON MITTON
SOUTH AFRICA
Logan Oplinger on fri 8 nov 02
Some materials/ingredients disperse differently if dry mixed before wet
mixing. Two examples will illustrate: 1. Extremely plastic/absorptive
materials such as bentonite, ball clay, etc.; and 2. Certain metallic
oxides. The bentonite or ball clay tend to clump, even if added to water
or a wet slurry in very small increments as the water or slurry is being
stirred. Metallic oxides, i.e. copper oxide, cobalt oxide, tend to remain
as very small granules of compact powder which form speckles in a glaze,
and/or the powder does not disperse into the water or slurry mix if added
dry because there appears to be a coating on the powder particles causing a
hydrophobic effect. This last property has been discussed before, with the
remedy being to blend a small amount (a few drops) of liquid detergent with
the oxide before adding to the water or slurry.
Logan Oplinger
Another Pacific Island
Latitude: 13.5 Longitude: -144.7
--ORIGINAL POST--
This is frequently brought up on Clayart ie.to "dry mix" ingredients before
adding to water. In my experience there does not appear to be any
difference as long as in "wet mixing" excess water and a blunger or whirler
are used. Would anyone like to present their "proof "to clayart that dry
mixing is necessary? RON MITTON SOUTH AFRICA
Tom's E-mail on fri 8 nov 02
Whenever I use bentonite in a glaze, I've found dry mixing to be an
advantage; one can avoid the lumping that otherwise occurs. In general, I
have the idea that other things go into solution more readily when dry
mixed. I dry mix using a method I saw Soldner use at a workshop. Place the
container on a wheel - fix the bucket with small clay plugs around the
perimeter - turn the wheel on and place your arm/hand in the spinning
bucket - lot easier than the shaking method.
Tom Sawyer
tsawyer@cfl.rr.com
Louis Ballard on fri 8 nov 02
To join in the discussion I have dry mixed 1000 grams of a celadon
glaze then measured out 100 gram test batches and added various amounts
of oxides to test 1%, 2%, 3% etc.....found a nice one, now i've moved
and can't find the test, black iron oxide at 3% i believe in the
standard 4-3-2-1.......i also want to do this with some base glaze
recipes i've found and add the stains in various increments, etc..
L.Ballard
----- Original Message -----
From: David Beumee
Date: Thursday, November 7, 2002 9:30 pm
Subject: Re: Clay and glazes..Dry mixing opinions
> Dear Ron,
> I think it is particularly important to put all the
> ingredients for a celedon glaze in a plastic bag,
> leave some air and seal the bag, then mix thoroughly by rolling
> the bag around on the floor. The small
> amount of iron is dispersed well, important in a celedon glaze.
> Also, if an accident occurs while pouring
> the dry ingredients into water, I know that some important
> ingredient hasn't been left out. Sometimes
> adding 99% pure red iron oxide or macaloid directly to water is a
> problem, a little like trying to get oil and
> water to mix in the case of pure red iron oxide, and mixing all
> the dry ingredients together eliminates this
> problem. I mix all my glazes dry inside a bag. I just get a better
> feeling about the glaze being a
> homogenous whole before it slakes down in the water.
>
> David Beumee
> Earth Alchemy Pottery
> Lafayette, Colodado
>
>
>
> 11/7/02 1:45:35 PM, Jean Mitton wrote:
>
> >This is frequently brought up on Clayart ie.to "dry mix"
> ingredients before adding to water.
> > In my experience there does not appear to be any difference
> as long as in "wet mixing" excess
> water and a blunger or whirler are used.
> > Would anyone like to present their "proof "to clayart that
> dry mixing is necessary?
> >
> > RON MITTON
> > SOUTH AFRICA
> >
>
>_______________________________________________________________________
_______
> >Send postings to clayart@lsv.ceramics.org
> >
> >You may look at the archives for the list or change your subscription
> >settings from http://www.ceramics.org/clayart/
> >
> >Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.>
>
>
________________________________________________________________________
______
> Send postings to clayart@lsv.ceramics.org
>
> You may look at the archives for the list or change your subscription
> settings from http://www.ceramics.org/clayart/
>
> Moderator of the list is Mel Jacobson who may be reached at
> melpots@pclink.com.
Dannon Rhudy on fri 8 nov 02
Tom said:
> Whenever I use bentonite in a glaze, I've found dry mixing to be an
> advantage; one can avoid the lumping that otherwise occurs.......
I was taught initially that dry-mixing bentonite was the way to add
it to a glaze. However, since that time I've learned a different way,
and I believe that it works better.
I mix any bentonite (or any hard-to-mix ingredient) with some
water in the studio blender. Bentonite does not really work, anyway,
until it is thoroughly wetted. So, I take some of the water intended
for the glaze, mix the bentonite (sometimes it takes two batches,
the bentonite will jell immediately and become very thick). Then
I add it to the glaze. Another method is just to keep a gallon
bucket of mixed bentonite to hand, if you've room. If you know
the water/bentonite ratio, then you can add the mixture to your
glaze, no problem, and it will work much, much better for it's
intended purpose. That is also how I add bentonite to a clay
body when needed.
regards
Dannon Rhudy
vince pitelka on fri 8 nov 02
> Whenever I use bentonite in a glaze, I've found dry mixing to be an
> advantage.
Tom's message reminded me that this is one situation where dry mixing helps,
but in this situation you need not dry mix the whole glaze. Just mix the
bentonite into whatever clay component is in the glaze before adding to the
water.
- Vince
Vince Pitelka
Appalachian Center for Crafts
Tennessee Technological University
1560 Craft Center Drive, Smithville TN 37166
Home - vpitelka@dtccom.net
615/597-5376
Work - wpitelka@tntech.edu
615/597-6801 ext. 111, fax 615/597-6803
http://www.craftcenter.tntech.edu/
Russel Fouts on sun 10 nov 02
>> As simple as it is to dry mix, this is not any big thing. As has been said numerous times on Clayart, dry mixing only requires a heavy cardboard shipping drum with the appropriate lid and clamp band. Fasten several lengths of 2x2 lumber up either side of the inside of the barrel with drywall screws driven through from the outside. Put all your dry materials in the barrel, clamp on the lid, tip it over, and roll it around the room for a minute or two, and you have thoroughly dry-mixed claybody. <<
This reminds me that someone was looking for a way to build a Soldner
type mixer easily and cheaply. His prototype for the mixer was described
in an article in Studio Potter. Wouldn't work or me, I don't have a car.
;-)
The article is available here:
http://studiopotter.org/articles/?art=art0018
>> Regarding glazes, I've been in ceramics for over thirty years, and I have never dry mixed a glaze. I can't see any advantage to that. <<
There Probably isn't unless you've included bentonite in the glaze.
I do find that adding the dry ingredients to water is less dust and
mixes better than the other way around. It also helps if you know how
much water you're going to need (and one should, according to Karl
Platt)
Russel
--
Russel Fouts
Mes Potes & Mes Pots
Brussels, Belgium
Tel: +32 2 223 02 75
Mobile: +32 476 55 38 75
Mailto:Russel.Fouts@Skynet.Be
Http://www.mypots.com
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