Hank Murrow on wed 8 oct 03
dear ash lovers,
I would just add this to the discussion.........unwashed ash, having
plenty of soluble alkali in it, will contribute noticeable irridescence
to the glaze.......which unwashed ash seldom encourages. I get very
nice 'raven's wing' irridescence on my Black Seto pulled pieces from
the anagama firings.
Hank in Eugene
ASHPOTS@AOL.COM on wed 8 oct 03
Hank, whats a black Seto ??????/
Mark on Lookout
Hank Murrow on wed 8 oct 03
On Wednesday, October 8, 2003, at 12:59 PM, ASHPOTS@AOL.COM wrote:
> Hank, whats a black Seto ??????/
> Mark on Lookout
When the Japanese potters around Seto finally received iron to make
tools (military trickle down) around 1570 (Momoyama era) or so, they
were able to make draw trials and pull them from the kiln. They noticed
that their tenmoku glazes , when cooled in air like this, did not turn
brown, but held a black-green color. It must have been a conceptual
leap, but they figured that they could add more iron to get a jet black
if they could pull the pots from the stoke holes and quick cool them.
Of course, they were only able to reach a few per firing for this
treatment, and those Momoyama era pots, even poor ones, go for 1
million yen ($100,000) if available at all. Arakawa re-discovered how
to make these pots in the Showa period around the 30s & 40s, and became
a National Living Treasure on the strength of his pulled Seto and Shino
revival pots. They used a very refractory clay mined around Mino for
dealing with the heat shock, and the Tea gurus love it for the soft
'like rain on thatch' sound the whisk makes in bowls made with this
punky clay. It probably vitrifies around C/15+.
I make my pots intended for such quick cooling from a body made up from
materials available stateside, and the black glaze from an Andesite
deposit that I mine on the Middle Fork of the Santiam River in the
Willamette Valley. It is so weathered that it makes a fine C/6 electric
body all by itself.......rings like a bell and is dark mahogany color
in oxidation. I add 6% unwashed Madrone ash to flux it a little more,
and to provide soluble alkali for the irridescence I mentioned earlier.
A lot of work for a jet black bowl, but Tea folk have praised it
highly, and you can see the results on my site @
http://www.murrow.biz/hank/woodfire-pots.htm . There is a nice lacy
pattern of black and silver if you look closely at the photo. The
irridescence does not show up under tungsten lighting, but it is there
My turn; what's 'on lookout'?
Cheers, Hank in Eugene
Lee Love on thu 9 oct 03
I found some rice straw ash walking my Akita dog Taiko in the fields this
morning. I'll go back with a bucket to collect some.
You can see some photos here:
I'm the one wearing the Golden Gopher's hockey Tshirt and the Straw
Lee In Mashiko
Stephen on thu 9 oct 03
I started working in an historic village 15 years ago and am still there. I
do a lot of raw glazing. My first ash glazes were before I came here. I
remember the glaze well. I have never washed the ashes except in an off
hand way as in pouring the water off the top of the glaze. That first ash
glaze was from a trash can full of ashes gathered from burning scrap wood,
mostly pine, stored in a farm in an old barn It had been there for years.
there were nails all in it. The fire burned allnight and and was a whitish
grey. All I did was mix this with water and aply it to bisque ware. It was
fired to cone 10 in a gas kiln. It was a wonderful bright grey speckled
glaze and I have never gotten anything like it again. The specks were
mostly black and brown from the nails, but there were also pink and blue
specks. My first ash glaze on greenware was also just ash and water, but
the results were very different. Whereever my hand toched the pot the glaze
came off and showed up on the finished peice. I salt glazed over this and
some of it was very interesting, but over all It was unsatisfactory. my
biggest problem was that the wood kiln I was using wasen't reaching
tempeture. The other ash glazes I have tried usually have 10 to 25 % of
some type of clay. My way of adjusting the glazes has been by way of
observation. I usually ajust the flux, add mre until I get a better over
all melt even in the back of the kiln where the tempeture is cooler. I have
gotten a wide rage of color and texture using both oak ashes from my fire
place and mixed pine/poplar/oak from the kiln. The kiln ashes are usually
more rugged and darker. There is a lot of incompletely burned ash in the
kiln as well as the same kind of nail specks as well as cinders from vaper
glaze. One last note: I have never noticed much caustic burn from the
unwashed ash which is something you often read as a caution.
Hank Murrow on thu 9 oct 03
On Thursday, October 9, 2003, at 02:59 AM, Lee Love wrote:
> I found some rice straw ash walking my Akita dog Taiko in the fields
> this morning. I'll go back with a bucket to collect some.
Hamada said that the ash from the hulls is richer in silica because its
job is to protect the seed, while the straw just supports it, and needs
less silica to do that. The seed itself is rich in alkali &
phosphate.......and makes a predictably soft ash.
Hamada's remarks were his answer to a person in the workshop who wanted
to know how to make glazes from ash when you 'don't have an analysis'.
He replied, "Look at what that part of the plant does...........and it
will tell you what it contains". While in technical school, he did
thousands of tests, and had lots of analytical backup..........yet he
resolved all that info down to simply considering what that part of the
plant does! Gotta love him.
Lee Love on fri 10 oct 03
----- Original Message -----
From: "Hank Murrow"
> Hamada said that the ash from the hulls is richer in silica because its
> job is to protect the seed, while the straw just supports it, and needs
> less silica to do that. The seed itself is rich in alkali &
> phosphate.......and makes a predictably soft ash.
Yes. Something I've wondered, because it is a material available
back home in Minnesota, is if Wild Rice husk can be substituted for rice
husk? At a Breshnehan workshop at Northern Clay Center, he mentioned that
he used wild rice husk as packing between the pots in a tumble stack in his
wood kiln. He said that wild rice husk was high in silica and that in the
wild, this coating work with periodic fires to protect the seed, and to
release it after a fire, to start new growth. Rice husk ash is used here
in Japan the same way Richard uses the wild rice husk.
> Hamada's remarks were his answer to a person in the workshop who wanted
> to know how to make glazes from ash when you 'don't have an analysis'.
> He replied, "Look at what that part of the plant does...........and it
> will tell you what it contains". While in technical school, he did
> thousands of tests, and had lots of analytical backup..........yet he
> resolved all that info down to simply considering what that part of the
> plant does! Gotta love him.
At my teacher's workshop, because almost all the glazes contained
ash, it would have been impossible to make the glaze according to the
analysis from a book or a computer program. We got ash from the
Woodcutter and there was no telling what kind of wood was used for the ash.
We could only be assured that the undesireable woods were not in it (like
pine, too much iron.)
But all the glazes were created through empherical testing.
When we washed a new batch of ash, the Retired Foreman would mix up a
standard batch and test them. From the tests, because of his experience,
he could eyeball the test tile and know exactly what to put in to fix it.
In the end, nobody knew exactly what was in the glaze and maybe the Foreman
even forgot what he put in it. That wasn't so important, only the final
All the Retired Foreman's measures were from wet ladle fulls of
materials. All the materials are kept wet in concrete containers or
plastic and stainless steel barrels and bins.
Usually, my teacher's base glaze was suppose to be half washed wood
ash and half ball clay, with additions of kaolin, according to the
temperature in the kiln where the ware would be fired. But the last batch
had washed wood ash from Ibaraki, If I remember correctly, 8 parts
Ibaraki wood ash, 3 parts Amakusa stone (one person called it porcelain
stone, a high silica white stone) with additions of kaolin, and whatever
else the Retired Foreman thought the glaze needed, but didn't write on the
tag on the container. When the Retired Foreman saw the initial results
of the woodash tests, he knew from experience that this ash would work
better with Amakusa.
Lee In Mashiko