Weird Bisque

[High Bridge Pottery]

Ok, so this happened.

 

 

I stacked them inside each other. Some of the other clays seem to have over fired slightly and these ones turned blue. Slight weird reduction maybe?? The one on the right is how it should look. I think they were too tightly packed and have had their own firing party.

 

Interesting anyway and a lesson for me in how to stack a bisque fire 

[Pres]

 I think what happened is as you said. The kiln gasses from organics and other changes in clay chemistry caused some local reduction to happen. You might also want to check your kiln with some cone packs to see if there is something going on with the elements. I have seen this happen where the inside would be an unnatural white, or some darker when boxing bowls with a pot inside them. Other times when packing a large jar with mugs or other items. All seems to work out in the glaze firing though.

 

Again, personal opinion not backed up by any science.

[neilestrick]

Yep. Just atmospheric differences in the kiln. Like Pres said it'll all go away in the glaze firing. It probably didn't over fire, just looks that way due to the reduction, but you'll know for sure if it takes glaze differently. You can fire them like that, but maybe slow down the firing a little bit at the high end.

[High Bridge Pottery]

Thanks for the information.

They actually look really cool and I would like to keep the two tone look. Just have to see what happens when I fire them. Look much more blue in real life.

[ashleigh_arts]

The best results I've had are from mis-fires! I know yours isn't technically a misfire....but it's the unexpected that keeps firing like Christmas morning!