[Strange blow outs during bisque fire]

Thanks.    I will take more care to avoid pockets when adding more clay.   Happy throwing to you all during this new year. 

[Strange blow outs during bisque fire]

These were with some other very large forms and I was trying to be over cautious.     

[Strange blow outs during bisque fire]

Preheated for 12 hours and slow fire digital.   Air dried for several weeks,   I had another  bowl that had the same kind of defect.   The thickness is consistent from bottom through the walls about the thickness of a pencil.   No one who has posted seems to have had this experience.   Just the expected defects from wet bottoms, too fast firing,   The second bowl had almost a perfect circle blow out  but half way between the bottom and rim.    I guess it is a ‘who knows’ just a fluke.    I was hoping for an answer that was more specific to this kind of event so it won’t be a future risk.     All in all thanks to everyone for all the information. 

[Strange blow outs during bisque fire]

No relation to spy hole.  Yes it is glazed.   It was glazed after the blow out.  

[Strange blow outs during bisque fire]

No relation to spy hole.  Yes it is glazed.   

[Strange blow outs during bisque fire]

This is on the side.    Specific details are in the very first post.   Thanks.  

[Strange blow outs during bisque fire]

Are your blow outs on the sides of your work?    These are not in the bottom like those that happen when water is left sitting in the bottom.  Thanks 

[Strange blow outs during bisque fire]

Are your blow outs on the sides of your work?    These are not in the bottom like those that happen when water is left sitting in the bottom.  Thanks 

[Strange blow outs during bisque fire]

Are your blow outs on the sides of your work?    These are not in the bottom like those that happen when water is left sitting in the bottom.  Thanks 

 

working on loading pics.   Blowout was on the side only, not a spiral or blow out on the bottom.  Been throwing for 35 years and never seen this before.   Thanks 

[Strange blow outs during bisque fire]

Recently I have had two strange blow outs during a bisque firing.  These pieces were large wheel thrown bowls ( approx. 20 wide and 9 tall) fired at cone 04 digital with a preheat of 8 hours.   The "defect" was a circular blow out of about 2 inches in diameter and pretty much a perfect circle.   The blowout did not go completely into the piece.  There were no other signs of cracks or defects.    Since this defect has occured twice, I need to find out what I am doing incorrectly so that I can prevent reoccurance.  Thanks.