[Bubbles In Black Stoneware]

32 minutes ago, Hulk said:

Per my limited experience, a hold at peak - adding heat work - may cause more fizzing. More heat work might clear things up for you, hmm. Are you firing same glazes, applied about same thickness, to other clays in same firing? Seeing same bubbling? In other words, any evidence that the problem is the clay vs. the glaze.

Looks like very small bubbles, which mostly heal over, but leave an orange peel look - excepting for the four (or so) larger holes, which may be a dry spot (where the glaze didn't wet the clay fully going on), or a larger chunk of something in the clay off gassing, or?

I found dropping and holding to help. No doubt you've already found links to Tony Hansen's articles, e.g. Drop-and-Soak Firing (digitalfire.com) and Glaze Bubbles (digitalfire.com); keep on it!

Keep good notes on each case...

I was just answering you on my post!

Yep! I found that schedule and was surprised! is it a 27hour firing??

[Bubbles In Black Stoneware]

4 hours ago, Roberta12 said:

@Titi  Could you attach a picture of the piece?  Pinholes might indicate a problem with the glaze.  Large bubbles (bloating) would be an issue with the clay.  

so you think with a hold on the Glaze fire could solve it?

[Bubbles In Black Stoneware]

4 minutes ago, Roberta12 said:

@Titi  Could you attach a picture of the piece?  Pinholes might indicate a problem with the glaze.  Large bubbles (bloating) would be an issue with the clay.  

 

Here it is!!

[Bubbles In Black Stoneware]

On 3/31/2020 at 4:54 PM, Lesley Anton said:

Ah wonderful!!!

I feel like I now have some awesome tools with all this great info. Tom, thank you!!! (and thank you Glazenerd!) I am a newcomer (not to clay but to Cone 6 firing/black clay/this forum, so I apologize that this is repetitive for those veterans on here. My clay history is cone 10 reduction so due to a recent move across the country, the situation has it that I needed to jump over to cone 5/6 oxidation.

I have done a ton of searches on this forum but if you don't have the right combo of wordage things don't pop up.  

Thanks again! 

I'm having the EXACT same issues with the PRNI clay, having little pinholes in my glaze firing  Using only Slow fire cone 04 and slow glaze at cone 6

Let us all know how it went! I particularly want to know.... I was thinking holding top temp on Bisque leaving peeps out, then glaze fire hold 20 mins.. I'm a newbie, never have I ever made my own firing program and I'm afraid to do it wrong ...