James Norton on tue 15 sep 98
A few weeks ago I submitted a question about the heat distribution in an
electric kiln. I said I used a cone 6 in the kiln setter, and had the
sitter shut off the current. I also placed two cone plaques (cones
4,5,and 6) in the middle of the lowest and highest shelves. I was
surprised that when the cone 6 shut off the kiln, the cones in the
middle showed about cone 4. I asked for advise on this apparent
inequality of heat distribution. Thanks to the many potters of good
will who offered their opinions. Several suggested that the difference
was only apparent, since the cone 6 in the sitter, being horizontal and
with the weight of the sensing rod, would actually deform earlier than
one placed nearly vertical. I checked this idea out by again firing
with a cone 6 in the sitter, but this time, I placed a cone plaque
(cones 4,5,and 6) on a shelf very close to the sitter cone. Sure
enough, when the sitter cone kicked off, the cone plaque cones
registered about cone 4. So it would seem tht if I wanted the ware to
be truly fired at cone 6, I should put a cone 7 or 8 in the sitter.
Does this seem reasonable? Is there a difference in using a cone or a
bar in the sitter? Thanks again for all the help.
the cat lady on wed 16 sep 98
>Date: Tue, 15 Sep 1998 21:58:18
>From: the cat lady
>Subject: Re: heat distribution
> So it would seem tht if I wanted the ware to
>>be truly fired at cone 6, I should put a cone 7 or 8 in the sitter.
>>Does this seem reasonable? Is there a difference in using a cone or a
>>bar in the sitter? Thanks again for all the help.
>I fire ^10 electric, and put a ^11 in the sitter. It usually turns
>off with ^9 at 4 o'clock. I turn the kiln back on and "babysit" it
>through to ^10 at 3 o'clock, and then a 30 minute soak. I use a full
>size cone with the bottom 1/3 snapped off.
>Hope this helps.
sam - alias the cat lady
SW Ontario CANADA
"Thousands of years ago, cats were worshipped as gods.
Cats have never forgotten this."