Mark Issenberg on wed 15 feb 12
I made 3 saggers and put 1 small cup in each. I used two different shinos a=
=3D
nd 3 different clays, I filled the the saggers with hard wood charcoal . I =
=3D
put a piece of kiln shelve over each.=3D20
I unloaded today and when I lifted the lid the charcoal was still there and=
=3D
hard. HOW? I fired to a hard cone 10 reduction.I was thinking I would have=
=3D
found ash.=3D20
The 3 cups are bubbly=3D20
Your thoughts
Going to Birmingham in the morning for the Alabama Clay Conference, hope to=
=3D
see you all there
Mark Issenberg
lookoutmountainpottery.com=3D20
Richard Aerni on thu 16 feb 12
Hey Mark,
I'm no chemist, and you'll no doubt get some definitive answers, but =3D
think about how charcoal is made...
Heating up wood without sufficient atmosphere of combustion. So, it =3D
would seem to me you took commercial charcoal and made it into cone 10 =3D
charcoal.
Enjoy the conference!
Richard Aerni
Rochester, NY
I made 3 saggers and put 1 small cup in each. I used two different =3D
shinos and 3
different clays, I filled the the saggers with hard wood charcoal . I =3D
put a
piece of kiln shelve over each.
I unloaded today and when I lifted the lid the charcoal was still there =3D
and
hard. HOW? I fired to a hard cone 10 reduction.I was thinking I would =3D
have found
ash.
The 3 cups are bubbly
Your thoughts
Snail Scott on thu 16 feb 12
On Feb 15, 2012, at 5:19 PM, Mark Issenberg wrote:
> ... I filled the the saggers with hard wood charcoal...when I lifted =3D
the lid the charcoal was still there...
Guessing that the saggars were pretty tight - not enough=3D20
oxygen getting in to sustain combustion/burnout.
-Snail=3D
Eric Ciup on thu 16 feb 12
Lack of oxygen.....can't burn.....same as carbon trap glaze
On 2/15/2012 6:19 PM, Mark Issenberg wrote:
> I made 3 saggers and put 1 small cup in each. I used two different shinos=
and 3 different clays, I filled the the saggers with hard wood charcoal . =
I put a piece of kiln shelve over each.
> I unloaded today and when I lifted the lid the charcoal was still there a=
nd hard. HOW? I fired to a hard cone 10 reduction.I was thinking I would ha=
ve found ash.
> The 3 cups are bubbly
> Your thoughts
> Going to Birmingham in the morning for the Alabama Clay Conference, hope =
to see you all there
>
> Mark Issenberg
> lookoutmountainpottery.com
Neil Estrick on thu 16 feb 12
I'm thinking your kiln shelf was too tight, and you created a nice insula=
=3D
ted box=3D20
that kept your glaze from maturing, with too little oxygen for the charco=
=3D
al to=3D20
combust.
Mike on fri 17 feb 12
Hi Mark,
I've had the same thing happen. You must have a good seal on those
saggars! No O2, and the charcoal can be reused again and again. I have
found with some glazes that too much charcoal results in some serious
bubbling. Back off on the amount of charcoal, or let a little air in
(you will get some ash then) and the bubbles will go away (mostly, your
mileage may vary).
Mike
in Taku, Japan
http://karatsupots.com
http://karatsupots.blogspot.com
Workshop in Taku 2012: The Simple Teabowl, May 12 - 18
http://karatsupots.com/workshop2012/2012home.html
http://workshopintaku2012.blogspot.com/
(2012/02/16 8:19), Mark Issenberg wrote:
> I made 3 saggers and put 1 small cup in each. I used two different shinos=
and 3 different clays, I filled the the saggers with hard wood charcoal . =
I put a piece of kiln shelve over each.
> I unloaded today and when I lifted the lid the charcoal was still there a=
nd hard. HOW? I fired to a hard cone 10 reduction.I was thinking I would ha=
ve found ash.
> The 3 cups are bubbly
> Your thoughts
> Going to Birmingham in the morning for the Alabama Clay Conference, hope =
to see you all there
>
> Mark Issenberg
> lookoutmountainpottery.com
>
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