search  current discussion  categories  techniques - cracking 

cracking (dunting?) during glaze firing

updated fri 9 sep 05

 

Paul Herman on thu 8 sep 05


Cathi,

From seeing at your pictures, it looks like the cracks come from the
forming methods, not the firing. Dunting cracks happen during or
after cooling, after the glaze has solidified. It would look like a
freshly broken pot.

Is the glaze healed over around the crack, like it was melted after
the crack happened? Take one of your cracked pots and break it up,
examining the cross section. Are there thick and thin areas on the
pot or it's foot? Thick and thin can cause stresses that show up in
the high firing, when the clay shrinks.

Good potting,

Paul Herman

Doyle, California
greatbasinpottery.com

On Sep 8, 2005, at 3:35 PM, MudPuppy wrote:

> I'm hoping some of you might have some insight into a problem I'm
> having with my ware cracking during ^9/10 glaze firing.
> The cracks seem like some sort of stress cracks, but I'm kinda new
> to this, and don't quite know what to make of them or how to remedy
> the problem.
> I have provided some details and photos if you could take the time
> to have a look...
> http://www.squarepegarts.com/content.php?article.1
>
> (sign me...
> Puzzled in Rural Mo.)
>
> Cathi Newlin, Mercer, Mo