MaryAnn Bowman on wed 23 oct 96
Help! My friend asked me to post this to the group. She is single firing
porcelain bowls with cobalt decoration under clear glaze to ^10 in a fairly new
Bailey electric kiln. She has been at this project for several years. Recently
she opened the kiln to discover one bowl had a large ash-like thing, white, very
gritty or crystalline when scrunched. It could be ground off, the bowl refired
with little harm done. The first time, the bowl was on the top shelf (the sky
is falling?), but the next time (not the very next firing) it was on a lower
shelf. She would prefer not to have a next time on this event so if anyone has
some thoughts about this mystery, let me know. TIA Mary Ann in Ithaca
Marvin Bartel on thu 24 oct 96
>----------------------------Original message----------------------------
>Help! My friend asked me to post this to the group. She is single firing
>porcelain bowls with cobalt decoration under clear glaze to ^10 in a
>fairly new
>Bailey electric kiln. She has been at this project for several years.
>Recently
>she opened the kiln to discover one bowl had a large ash-like thing,
>white, very
>gritty or crystalline when scrunched. It could be ground off, the bowl
>refired
>with little harm done. The first time, the bowl was on the top shelf (the sky
>is falling?), but the next time (not the very next firing) it was on a lower
>shelf. She would prefer not to have a next time on this event so if anyone has
>some thoughts about this mystery, let me know. TIA Mary Ann in Ithaca
This may be the result of leaving a piece of paper in the bowl when loading
the kiln. We get these if students forget to remove instruction notes
while loading. I get lots of notes that say: "Please Reduce," and I'm not
even that heavy. Marvin Bartel
Cobalt1994@aol.com on thu 24 oct 96
very
I had this type of thing showing up on pots several years ago and it turned
out to be a white firing grog my supplier had switched to. It was a mineral
or something that bloated during my bisque firing to produce white fluffy
gritty protrusions. Is there grog in the clay?
Jennifer in Vermont
cobalt1994@AOL.com
Sam Cuttell on thu 24 oct 96
Strange that this thread should come up right now. I just unloaded my kiln,
and for some strange reason, the newly applied kiln wash on the top shelf
(all my shelves were freshly coated at the same time) had crazed and gently
floated into the pots on the top shelf.
The good news is that it only happened on one shelf. It ruined 6 spoon
rests - so no heavy loss HOWEVER
I would like to avoid this in the future. I have been using the same bag of
kiln wash (bought from Pottery Supply House) for 6 or so years (hey, 5 kilos
is a lot of kiln wash)...same firing schedule, etc. etc. etc.
Can this stuff get too "old"?
Anyone had this happen? How do I prevent this from happening to let's say a
load of T-Pots (heaven forbid!!)
HELP!
sam - alias the cat lady
Home of Manx cats, Cavalier King Charles Spaniels and the odd horse
Melbourne, Ontario, CANADA
(SW Ontario)
http://www.geocities.com/paris/3110
Susan Ammann on fri 25 oct 96
Speaking of weird (gross) things in the kiln, I found a perfect mouse
skeleton on a shelf. It crumbled into dust when I tried to lift it
out. I hate to even think about that mouse's last minutes.
Susan Ammann
Susanfam@laplaza.org
Suzanne Storer on fri 25 oct 96
It sounds like a bit of soft brick landing on the bowl. I pretty much
eliminated this in my kiln by vacuuming the inside before each glaze firing.
At 08:42 PM 10/23/96 EDT, you wrote:
>----------------------------Original message----------------------------
>Help! My friend asked me to post this to the group. She is single firing
>porcelain bowls with cobalt decoration under clear glaze to ^10 in a fairly new
>Bailey electric kiln. She has been at this project for several years.
Recently
>she opened the kiln to discover one bowl had a large ash-like thing, white,
very
>gritty or crystalline when scrunched. It could be ground off, the bowl refired
>with little harm done. The first time, the bowl was on the top shelf (the sky
>is falling?), but the next time (not the very next firing) it was on a lower
>shelf. She would prefer not to have a next time on this event so if anyone has
>some thoughts about this mystery, let me know. TIA Mary Ann in Ithaca
>
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