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paul borian's ash problem

updated thu 3 jun 10

 

Richard Aerni on tue 1 jun 10


Pardon the huge cut and paste, but I've been at the studio the past =3D
couple of days firing and out of touch with clayart...

Paul,
You are suffering from flocculation problems due to the high alkaline =3D
content in your unwashed wood ash. For years I used to only mix a =3D
kilnload at a time to avoid the pudding-like consistency after a few =3D
days time. Like you, I spray my ash glazes on. Adding water does =3D
nothing but make the problem worse. I tried adding vinegar to change =3D
the ph, and other likely solutions. Now, here are a couple of ideas for =
=3D
you to try...may not work for you, but works for me and now I can keep =3D
my ash glazes handy and usable for months on end. =3D20
For the floc problem, get some Darvan 7 and add some to the wood ash =3D
glaze. I usually mix up the glaze in 2000 gram batches wet, and about =3D
1-2 teaspoons makes it good to go. Darvan 7 has a wide range at which =3D
it keeps things deflocced, so that's why I use it. Other deflocculants, =
=3D
if you put in a drop too much, you get pudding...it goes the other way. =
=3D
I buy it by the gallon...a great investment. You say you mix 25 gallons =
=3D
at a time...you must be a real production monster. I mix my wood ash =3D
glaze up 20,000 grams at a time, but leave it in the dry state. I just =3D
add water to it whenever I need some for a firing. =3D20
As for the cracking and falling off...I only get this problem when the =3D
glaze has flocced and gotten all puddinglike. Then there is so much =3D
water in it, the shrinkage as the water is absorbed into the pot is so =3D
great the the glaze cracks and falls off. The Darvan 7 should solve the =
=3D
problem, but just in case you are using the glaze differently than I, =3D
and that is not the problem, try adding a couple of per cent of =3D
bentonite to your dry glaze mix. This will toughen up the skin and help =
=3D
increase the "sticking power" of the glaze. =3D20
If you want to see pots and talk ash glazes, I'll be in Cincinnati on =3D
June 19 at a sale in Hyde Park. Check out my facebook page if you want =3D
details, or email me. Nothing like talking pots and wood ash!
Good luck with this!
Richard


Fwd: Reverse engineering hardwood ash?=3D20


thanks for the replies.
my main problem is really with the application. I have been using this =3D
ash
glaze for a long time and typically mix about 25 gallons at a time, =3D
adding
about 4% and some of axner's "flocs", plus i add cmc powder as needed =3D
which
i think helps the glaze stick to the pots after being sprayed on without
cracking and flaking off when it dries. This worked fine until i mixed a =
=3D
new
batch from a different stash of ash since my old stash was used up.
now the new batch of glaze has this cracking problem no matter how much =3D
or
how little cmc i add.
i keep this glaze very thick in the bucket because extra water makes the
problem worse. If the glaze was any thicker it would not spray at all =3D
yet i
still have this problem.

does anyone know of another solution to this problem, other than =3D
switching
to a fake ash? the idea of adding portland cement sounds interesting but =
=3D
i
am concerned that one day i would find a bucket of hardened cement when =3D
i
really needed to get work done.

thanks,
Paul
---------- Forwarded message ----------
From: Eric Hansen
Date: Mon, May 31, 2010 at 5:18 PM
Subject: Re: Reverse engineering hardwood ash?
To: Clayart@...


Amen; before giving up on wood ash look at Aerni's site:

http://www.richardaerni.com/

Washing ash will remove the soluble alkalies, the caustics, yes. Washing
also allows finer screening of the ash. 40 mesh is good for me but some
might prefer 100 mesh. Ball-milling is even better. You might also want =3D
to
standardize each ash product. Such as, firewood, fruit tree wood =3D
prunings,
rice hull or rice straw, reed ash, bracken ash. Wood has the smallest =3D
return
percentage wise, most of it burns off. Grasses can yield many times the
amount of ash per pound. Also consider a standardized way of cooking =3D
ash.
Such as Gary Navarre's Koie Cooker:

http://www.google.com/search?q=3D3DKoie+cooker&hl=3D3Den&client=3D3Dsafari&=
rls=3D3D=3D
en&prmd=3D3Dv&sou\
rce=3D3Duniv&tbs=3D3Dvid:1&tbo=3D3Du&ei=3D3DjCEETOWzAcWblgf_k-iBDQ&sa=3D3DX=
&oi=3D3Dvi=3D
deo_result_group&ct\
=3D3Dtitle&resnum=3D3D4&ved=3D3D0CDMQqwQwAw

Also there are ways to tame the ash glaze using certain percentages of
feldspars and clays in addition to the ash.
h a n s e n
p.s. using the UPA to reconstruct a chemically identical formula will =3D
work,
however the results will be different with every substitution you make. =3D
How
different will depend on which substitutions they are.

On Mon, May 31, 2010 at 10:01 AM, David Beumee wrote:

> What I read is that the basic problem is that the ash is caustic, =3D
easily
> remedied by washing out the soluble alkalis.Yes, it will change the =3D
look
of
> the glaze, but you have a better chance of retaining the subtle =3D
qualities
> of
> your particular ash by fixing the problem than by trying to reproduce
> nature
> through chemical analysis and the UMF.
>
> David Beumee
> Lafayette, CO
>
>
>
>
>
>
>
>
>
>
>
>
> On Sun, May 30, 2010 at 12:17 PM, Paul Borian > >wrote:
>
> > i have been using hardwood ash in one of my glazes for years and it =3D
is a
> > major part of my product line.
> > however, i have never like working with it because it is caustic and =
=3D
it
> > presents numerous glaze application problems.
> > i know there are fake ash glazes out there but it would take a lot =3D
of
> time
> > to seek them out and test them all and hope i find one that looks =3D
the
> same.
> > So, i was thinking to send a sample of the hardwood ash i currently =3D
use
> off
> > to a lab to get the chemical analysis. With that info, would it be
> possible
> > to reformulate it as a fake ash glaze by making the necessary
substitions
> > to
> > get a glaze with the same unity formula?
> > Basically i just want to come up with a substitute for wood ash with =
=3D
the
> > same chemical analysis as the ash i currently use.
> > Possible or impossible?
> > anyone care to comment?
> > thanks,
> > Paul

Edouard Bastarache on wed 2 jun 10


Richard,

I use washed woodash,
I always add at least 2% Bentonite, and Epsom Salt.
Some of my ash glazes have been standing on the shelve
for close to 15 years; no problems re-suspending them.
I dip and pour, no spraying for me.
I have used ashes from 30 to 200 meshes.
The 200 melts better,

I am a glaze, toxicology and joke freak
GRIN!!!

Gis,

Edouard Bastarache
Spertesperantisto

Sorel-Tracy
Quebec

http://www.flickr.com/photos/30058682@N00/
http://edouardbastarache.blogspot.com/
http://blogsalbertbastarache.blogspot.com/
http://cerampeintures.blogspot.com/
http://perso.wanadoo.fr/smart2000/index.htm



----- Original Message -----
From: "Richard Aerni"
To:
Sent: Tuesday, June 01, 2010 8:10 PM
Subject: Paul Borian's ash problem


Pardon the huge cut and paste, but I've been at the studio the past couple
of days firing and out of touch with clayart...

Paul,
You are suffering from flocculation problems due to the high alkaline
content in your unwashed wood ash. For years I used to only mix a kilnload
at a time to avoid the pudding-like consistency after a few days time. Lik=
e
you, I spray my ash glazes on. Adding water does nothing but make the
problem worse. I tried adding vinegar to change the ph, and other likely
solutions. Now, here are a couple of ideas for you to try...may not work
for you, but works for me and now I can keep my ash glazes handy and usable
for months on end.
For the floc problem, get some Darvan 7 and add some to the wood ash glaze.
I usually mix up the glaze in 2000 gram batches wet, and about 1-2 teaspoon=
s
makes it good to go. Darvan 7 has a wide range at which it keeps things
deflocced, so that's why I use it. Other deflocculants, if you put in a
drop too much, you get pudding...it goes the other way. I buy it by the
gallon...a great investment. You say you mix 25 gallons at a time...you
must be a real production monster. I mix my wood ash glaze up 20,000 grams
at a time, but leave it in the dry state. I just add water to it whenever =
I
need some for a firing.
As for the cracking and falling off...I only get this problem when the glaz=
e
has flocced and gotten all puddinglike. Then there is so much water in it,
the shrinkage as the water is absorbed into the pot is so great the the
glaze cracks and falls off. The Darvan 7 should solve the problem, but jus=
t
in case you are using the glaze differently than I, and that is not the
problem, try adding a couple of per cent of bentonite to your dry glaze mix=
.
This will toughen up the skin and help increase the "sticking power" of the
glaze.
If you want to see pots and talk ash glazes, I'll be in Cincinnati on June
19 at a sale in Hyde Park. Check out my facebook page if you want details,
or email me. Nothing like talking pots and wood ash!
Good luck with this!
Richard


Fwd: Reverse engineering hardwood ash?


thanks for the replies.
my main problem is really with the application. I have been using this ash
glaze for a long time and typically mix about 25 gallons at a time, adding
about 4% and some of axner's "flocs", plus i add cmc powder as needed which
i think helps the glaze stick to the pots after being sprayed on without
cracking and flaking off when it dries. This worked fine until i mixed a ne=
w
batch from a different stash of ash since my old stash was used up.
now the new batch of glaze has this cracking problem no matter how much or
how little cmc i add.
i keep this glaze very thick in the bucket because extra water makes the
problem worse. If the glaze was any thicker it would not spray at all yet i
still have this problem.

does anyone know of another solution to this problem, other than switching
to a fake ash? the idea of adding portland cement sounds interesting but i
am concerned that one day i would find a bucket of hardened cement when i
really needed to get work done.

thanks,
Paul
---------- Forwarded message ----------
From: Eric Hansen
Date: Mon, May 31, 2010 at 5:18 PM
Subject: Re: Reverse engineering hardwood ash?
To: Clayart@...


Amen; before giving up on wood ash look at Aerni's site:

http://www.richardaerni.com/

Washing ash will remove the soluble alkalies, the caustics, yes. Washing
also allows finer screening of the ash. 40 mesh is good for me but some
might prefer 100 mesh. Ball-milling is even better. You might also want to
standardize each ash product. Such as, firewood, fruit tree wood prunings,
rice hull or rice straw, reed ash, bracken ash. Wood has the smallest retur=
n
percentage wise, most of it burns off. Grasses can yield many times the
amount of ash per pound. Also consider a standardized way of cooking ash.
Such as Gary Navarre's Koie Cooker:

http://www.google.com/search?q=3DKoie+cooker&hl=3Den&client=3Dsafari&rls=3D=
en&prmd=3Dv&sou\
rce=3Duniv&tbs=3Dvid:1&tbo=3Du&ei=3DjCEETOWzAcWblgf_k-iBDQ&sa=3DX&oi=3Dvide=
o_result_group&ct\
=3Dtitle&resnum=3D4&ved=3D0CDMQqwQwAw

Also there are ways to tame the ash glaze using certain percentages of
feldspars and clays in addition to the ash.
h a n s e n
p.s. using the UPA to reconstruct a chemically identical formula will work,
however the results will be different with every substitution you make. How
different will depend on which substitutions they are.

On Mon, May 31, 2010 at 10:01 AM, David Beumee wrote:

> What I read is that the basic problem is that the ash is caustic, easily
> remedied by washing out the soluble alkalis.Yes, it will change the look
of
> the glaze, but you have a better chance of retaining the subtle qualities
> of
> your particular ash by fixing the problem than by trying to reproduce
> nature
> through chemical analysis and the UMF.
>
> David Beumee
> Lafayette, CO
>
>
>
>
>
>
>
>
>
>
>
>
> On Sun, May 30, 2010 at 12:17 PM, Paul Borian > >wrote:
>
> > i have been using hardwood ash in one of my glazes for years and it is =
a
> > major part of my product line.
> > however, i have never like working with it because it is caustic and it
> > presents numerous glaze application problems.
> > i know there are fake ash glazes out there but it would take a lot of
> time
> > to seek them out and test them all and hope i find one that looks the
> same.
> > So, i was thinking to send a sample of the hardwood ash i currently use
> off
> > to a lab to get the chemical analysis. With that info, would it be
> possible
> > to reformulate it as a fake ash glaze by making the necessary
substitions
> > to
> > get a glaze with the same unity formula?
> > Basically i just want to come up with a substitute for wood ash with th=
e
> > same chemical analysis as the ash i currently use.
> > Possible or impossible?
> > anyone care to comment?
> > thanks,
> > Paul

Lee Love on wed 2 jun 10


Another solution, to eep the effects of unwashed wood ash, but not the
hazards, is to wash the ash and keep the wash. Use the wash as a dip
before you glaze with the washed ash. If you dont want to keep the
wash water, you can also make a soda ash solution as a pre-dip.

--
Lee, a Mashiko potter in Minneapolis
http://mingeisota.blogspot.com/

=3D93Observe the wonders as they occur around you. Don't claim them. Feel
the artistry moving through and be silent.=3D94 --Rumi

Richard Aerni on wed 2 jun 10


Edouard wrote:
I use washed woodash,
I always add at least 2% Bentonite, and Epsom Salt.
Some of my ash glazes have been standing on the shelve
for close to 15 years; no problems re-suspending them.
I dip and pour, no spraying for me.
I have used ashes from 30 to 200 meshes.
The 200 melts better,

Edouard,
I think you need to clean your studio more often!
Everyone uses ash glazes in a different manner, it's difficult to make a =
=3D
generalization that works for all. If you have found something that =3D
works, go with it.
I don't wash my wood ash glaze...like them with the alkaline halo for =3D
starters, and also, I don't like to spend time on tasks that I might not =
=3D
need to do. To wash ashes, you have to soak, decant, soak, decant, dry, =
=3D
then repulverize and resieve (at least the way I use them)...as a =3D
self-supporting studio potter, I just don't have the time to do that. =3D20
Best,
Richard...wondering if there is such a thing as a politically correct =3D
joke...
Richard Aerni
Rochester, NY =3D20
www.richardaerni.com