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semi-melted bisque firing

updated thu 18 nov 10

 

Kathy Forer on mon 15 nov 10


I was thinking in fahrenheit while my digital thermometer was in =3D
Centigrade. So the kiln went up to 1350=3DB0C, about cone 13 or 2500=3DB0F.=
=3D20=3D


I missed all the warning signs this was happening.

My big old Paragon was used to taking at least that much time, =3D
overnight, to get to temp. I'd monitored it with a video cam, visited it =
=3D
every hour, taken its temperature and observed its cones every half =3D
hour. Made graphs. In this case I was just careless. I'd only fired the =3D
small L&L econokiln once before and though I remember it being fast, it =3D
didn't make a huge impression.=3D20

I've opened the kiln lid and it wasn't as bad as it might have been. The =
=3D
middle shelf shattered and things collapsed but the kids' stuff is =3D
mostly okay, though fused one to another and one big bowl to the kiln =3D
shelf. One piece of mine was dark brown and half-melted. Must have been =3D
a low cone clay to begin with, must investigate.=3D20

So now I have 18" shelves with melted cones all over them. Also a cone =3D
melted in the kiln sitter. And the digital thermocouple probe is quite =3D
bent out of shape. I may need to replace that. Everything else looks =3D
okay. When the shelf collapsed, its edge went into soft brick, not =3D
elements, so that was good.

Is there a "best way" to clean up the kiln sitter and remove the melted =3D
cone?=3D20

It wasn't the worst thing, there was no fire, god forbid, and the kiln =3D
appears to have survived. It actually made me somewhat more confident =3D
that it's not so scary to do it right. It can even be done fairly =3D
quickly if the pieces allow. Until recent austerity measures, I'd been =3D
used to firing large single pieces, up to 1-3" in thickness, 12-18" x =3D
20-27". Not much consideration for weight. They were built well so they =3D
survived but had to be fired very slowly. Now that I'm doing some =3D
smaller and lighter pieces, they can be fired more quickly, faster =3D
turnaround, more satisfaction. Maybe I'll even experiment more with =3D
color.=3D20


Kathy Forer
www.foreverink.com

Snail Scott on mon 15 nov 10


On Nov 15, 2010, at 11:53 AM, Kathy Forer wrote:
> Is there a "best way" to clean up the kiln sitter and remove the
> melted cone?
>

Just replace the rod and cone supports. If
you can save the rod in place, it's less work,
but still not tough to replace if you've gotta.
Cone supports are dead easy to swap out.

-Snail

Hank Murrow on tue 16 nov 10


On Nov 15, 2010, at 4:10 PM, Snail Scott wrote:

> On Nov 15, 2010, at 11:53 AM, Kathy Forer wrote:
>> Is there a "best way" to clean up the kiln sitter and remove the
>> melted cone?
>>=3D20
>=3D20
> Just replace the rod and cone supports. If
> you can save the rod in place, it's less work,
> but still not tough to replace if you've gotta.
> Cone supports are dead easy to swap out.

Hank Murrow treats his supports and rod with kiln wash every once in a =3D
while in case an iron-bearing cone gets aggressive. An alternative is to =
=3D
use white iron-free cones.

Cheers, Hank=3D