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ash: wash how many times?

updated thu 10 may 07

 

Hank Murrow on sun 6 may 07


On May 6, 2007, at 1:51 PM, Josh Berkus wrote:

> All,
>
> I've been hunting through the ClayArt archives for suggestions on
> Cone 6 ash
> glazes since I know my Cone 10 ash glazes will not work at Cone 6
> and can't
> be easily adjusted.
>
> However, I've noticed a couple of things which confuse me:
>
> Unwashed: What's the issue with using unwashed ash? I have a Cone
> 10 unwashed
> ash glaze I've been using to get Shino-like affects on oxidized
> ware. It
> stinks something awful after a couple weeks in the bucket, but I
> haven't
> noticed any other problem effects. What's wrong with unwashed ash,
> other
> than the dirt/mineral particles?
>
> Wash How Many Times: other recipes I come across, like those in
> this thread:
> http://www.potters.org/subject37350.htm , don't indicate how many
> times ash
> is washed, or even if it's washed at all. If a recipe just says
> "wood ash"
> can I make any assumptions about washing?

Dear Josh;

The problem with unwashed ash is that the solubles are removed with
the water, thus changing the flux ratio each time you use it(unless
you replace some of the lost solubles). I don't mind this at all, sdo
I mainly use unwashed ash unless the recipe i am trying calls for
washed ash. Even then, I would do two tests to see which one works
the best.

Cheers, Hank
www.murrow.biz/hank

Josh Berkus on sun 6 may 07


All,

I've been hunting through the ClayArt archives for suggestions on Cone 6 ash
glazes since I know my Cone 10 ash glazes will not work at Cone 6 and can't
be easily adjusted.

However, I've noticed a couple of things which confuse me:

Unwashed: What's the issue with using unwashed ash? I have a Cone 10 unwashed
ash glaze I've been using to get Shino-like affects on oxidized ware. It
stinks something awful after a couple weeks in the bucket, but I haven't
noticed any other problem effects. What's wrong with unwashed ash, other
than the dirt/mineral particles?

Wash How Many Times: other recipes I come across, like those in this thread:
http://www.potters.org/subject37350.htm , don't indicate how many times ash
is washed, or even if it's washed at all. If a recipe just says "wood ash"
can I make any assumptions about washing?

--
The Fuzzy Chef
San Francisco

David Beumee on mon 7 may 07


Hank wrote:
"> The problem with unwashed ash is that the solubles are removed with
> the water, thus changing the flux ratio each time you use it(unless
> you replace some of the lost solubles)."

It is the process of washing ash that removes soluble alkalis. All of the solubles are present in the use of unwashed ash.

David Beumee
Lafayette, CO













-------------- Original message ----------------------
From: Hank Murrow
>
> On May 6, 2007, at 1:51 PM, Josh Berkus wrote:
>
> > All,
> >
> > I've been hunting through the ClayArt archives for suggestions on
> > Cone 6 ash
> > glazes since I know my Cone 10 ash glazes will not work at Cone 6
> > and can't
> > be easily adjusted.
> >
> > However, I've noticed a couple of things which confuse me:
> >
> > Unwashed: What's the issue with using unwashed ash? I have a Cone
> > 10 unwashed
> > ash glaze I've been using to get Shino-like affects on oxidized
> > ware. It
> > stinks something awful after a couple weeks in the bucket, but I
> > haven't
> > noticed any other problem effects. What's wrong with unwashed ash,
> > other
> > than the dirt/mineral particles?
> >
> > Wash How Many Times: other recipes I come across, like those in
> > this thread:
> > http://www.potters.org/subject37350.htm , don't indicate how many
> > times ash
> > is washed, or even if it's washed at all. If a recipe just says
> > "wood ash"
> > can I make any assumptions about washing?
>
> Dear Josh;
>
> The problem with unwashed ash is that the solubles are removed with
> the water, thus changing the flux ratio each time you use it(unless
> you replace some of the lost solubles). I don't mind this at all, sdo
> I mainly use unwashed ash unless the recipe i am trying calls for
> washed ash. Even then, I would do two tests to see which one works
> the best.
>
> Cheers, Hank
> www.murrow.biz/hank
>
> ______________________________________________________________________________
> Send postings to clayart@lsv.ceramics.org
>
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>
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Edouard Bastarache Inc. on mon 7 may 07


Hello,

I wash thrice and get rid of the solubles nasty
for the skin.


Later,




Edouard Bastarache
Le Franšais Volant
The Flying Frenchman

Sorel-Tracy
Quebec
http://www.sorel-tracy.qc.ca/~edouardb/Welcome.html
http://perso.orange.fr/smart2000/livres.htm
http://www.pshcanada.com/Toxicology.htm
http://www.flickr.com/photos/30058682@N00/
http://perso.orange.fr/smart2000/blogs_edouard.htm

Ric Swenson on mon 7 may 07


Three for me....-ric
=20
=20



> Date: Mon, 7 May 2007 11:55:27 -0400> From: edouardb@SOREL-TRACY.QC.CA> S=
ubject: Re: Ash: wash how many times?> To: CLAYART@LSV.CERAMICS.ORG> > Hell=
o,> > I wash thrice and get rid of the solubles nasty> for the skin.> > > L=
ater,> > > > > Edouard Bastarache> Le Fran=E7ais Volant> The Flying Frenchm=
an> > Sorel-Tracy> Quebec> http://www.sorel-tracy.qc.ca/~edouardb/Welcome.h=
tml> http://perso.orange.fr/smart2000/livres.htm> http://www.pshcanada.com/=
Toxicology.htm> http://www.flickr.com/photos/30058682@N00/> http://perso.or=
ange.fr/smart2000/blogs_edouard.htm> > ____________________________________=
__________________________________________> Send postings to clayart@lsv.ce=
ramics.org> > You may look at the archives for the list or change your subs=
cription> settings from http://www.ceramics.org/clayart/> > Moderator of th=
e list is Mel Jacobson who may be reached at melpots@pclink.com.
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Vince Pitelka on tue 8 may 07


Josh Berkus wrote:
> Unwashed: What's the issue with using unwashed ash? I have a Cone 10
> unwashed
> ash glaze I've been using to get Shino-like affects on oxidized ware. It
> stinks something awful after a couple weeks in the bucket, but I haven't
> noticed any other problem effects. What's wrong with unwashed ash, other
> than the dirt/mineral particles?

Josh -
Some people go way over the top in their fear of unwashed ash in water.
That is how they make lye, after all. But as long as proper safety
practices are followed, this isn't a problem. Wear safety glasses while
mixing and applying ash glazes, and keep your hands out of the glaze as much
as possible. Many people wear rubber gloves while using ash glazes. I've
never done that. I just keep my hands out of the glaze, and wash off
thoroughly if I do get glaze on my hands. We use a LOT of ash glazes at the
Craft Center, and they are all made with unwashed ash.

If you use washed ash, you've removed much of the flux from the ash, and you
need to supply the flux elsewhere. Most people who seek the classic broken,
rivulet effect with ash glazes claim that you cannot get the best effects
with washed ash.

If a recipe just specifies "wood ash," I think you can assume that they mean
unwashed ash.
- Vince

Vince Pitelka
Appalachian Center for Craft, Tennessee Technological University
Smithville TN 37166, 615/597-6801 x111
vpitelka@dtccom.net, wpitelka@tntech.edu
http://iweb.tntech.edu/wpitelka/
http://www.tntech.edu/craftcenter/

Lee Love on wed 9 may 07


On 5/9/07, Richard Aerni wrote:
> I hate to be difficult here, but my experience is different from Vince's and
> Lee's...

What you say doesn't conflict with my experience. I only
disagreed with Vince when he said you need the soluables for a runny
ash glaze. You don't.

This is my Hamada Irabo:

dobai (washed) 4 (wood ash)
amakusa toseki 1.5 (Arita porcelain stone)
odo (ocher) 2

Here is Sander's Tamba:

Alberta slip 60
Wood ash 40

add: R.I.Ox 5%

These are similar glazes. I brush on a thin coat at the
bottom and dip the top 1/3 to 1/2 of the top only, because both
glazes will run to the bottom of the pot, with washed wood ash,
especially in woodfire or soda.

> If you look at most "fake ash" recipes, which give the ashy runs, they will
> typically include at least 30% calcium (limestone, wollastonite) in them, to
> create that effect.

Ash is a sort of impure whiting. You can begin exploring
wood ash by substituting it for whiting in a glaze.
I always use synthetic wood ash as a baseline for my first test of
an ash glaze. This is a "common synthetic ash" I usually use:



Bone ash 4.532
Dolomite 15.172
EPK 23.741
Custer feldspar 37.452
Whiting 27.301


--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.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

Richard Aerni on wed 9 may 07


I hate to be difficult here, but my experience is different from Vince's and
Lee's...
Unwashed ash indeed has lots of soluble alkaline fluxes, which do melt into
the clay body and produce a nice "halo" effect around the ash run. The
rivulet effect, as I know it, and understand it, is produced from the large
amounts of calcium in the wood ash glaze. Calcium, when melted, has a high
surface tension (remember high school chemistry with the meniscus effect of
water in a graduated cylinder? It's the same deal with the melted ash...),
so that rather than spreading out, like a typical glossy glaze does, it
beads up, and then runs, when the glaze is melted sufficiently, and gravity
has it's way with it.
If you look at most "fake ash" recipes, which give the ashy runs, they will
typically include at least 30% calcium (limestone, wollastonite) in them, to
create that effect.
Off to deliver pots to galleries...
Best,
Richard Aerni
Rochester, NY

On Wed, 9 May 2007 09:07:29 +0900, Lee Love wrote:

>On 5/8/07, Vince Pitelka wrote:
>
>> If you use washed ash, you've removed much of the flux from the ash, and you
>> need to supply the flux elsewhere. Most people who seek the classic broken,
>> rivulet effect with ash glazes claim that you cannot get the best effects
>> with washed ash.
>
> My runny ash glaze, using Hamada's Irabo recipe is washed ash and
>ocher clay. Back home, I used Sander's Tamba, which was washed ash
>and Michigan/Alberta slip.
>
> Fluxes cause the running and they don't have to come soluble fluxes
>that are washed out of the wood ash
>
>

Lee Love on wed 9 may 07


On 5/8/07, Vince Pitelka wrote:

> If you use washed ash, you've removed much of the flux from the ash, and you
> need to supply the flux elsewhere. Most people who seek the classic broken,
> rivulet effect with ash glazes claim that you cannot get the best effects
> with washed ash.

My runny ash glaze, using Hamada's Irabo recipe is washed ash and
ocher clay. Back home, I used Sander's Tamba, which was washed ash
and Michigan/Alberta slip.

Fluxes cause the running and they don't have to come soluble fluxes
that are washed out of the wood ash

One way to get rid of the variablility is to keep the washing
water and then dip in the water before applying the washed ash glaze.


--
Lee in Mashiko, Japan
Minneapolis, Minnesota USA
http://mashikopots.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