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I've been testing a dug clay that is really nice except that every glaze I've tried on it pinholes even with soaks and slow cool downs. I had to bisque up to cone 02 and do a soak to get it to stop pinholeing.

Jim

blisters/pinholes are sometimes difficult to diagnose/remedy.

there are numerous causes. hopefully, in your case, it's an isolated incident with a glaze you have been using without issue. *if it's a new glaze and not the result of things like dust on bisque ware you need to re-evaluate every ingredient. there are some usual suspects and searches on the digitalfire website will identify most of the culprits.*

we fire to a 04 bisque which helps to alleviate some issues but in the end we've had to abandon a few glazes because of blistering/pinhole issues.

it's fun trying to figure a glaze out but after you've exhausted every internet resource and you are tired of making excuses for that one blister that always shows up - it's time to let the glaze go. for a couple of firings anyway.

re-firing, in my experience, does not work. every glaze has it own personality so hopefully you have some success. we've only ever tried re-firing to the same temperature as the initial firing but we were only trying to fix the most severe cases.

long story short - don't get too attached to a dysfunctional glaze unless you really enjoy testing glazes.

p.s
i learned the hard way that a failing thermocouple will lead to over-firing will lead to blistering so careful your temperature isn't creeping up on you.

*p.p.s.
i really dislike blisters.

**please excuse my failure at reading comprehension. i'm guilty of not reading and understanding the entire thread before braving a reply. it was late - i was tired.

some glazes just refuse to get along.

/lurk

blisters/pinholes are sometimes difficult to diagnose/remedy.

there are numerous causes. hopefully, in your case, it's an isolated incident with a glaze you have been using without issue. *if it's a new glaze and not the result of things like dust on bisque ware you need to re-evaluate every ingredient. there are some usual suspects and searches on the digitalfire website will identify most of the culprits.*

we fire to a 04 bisque which helps to alleviate some issues but in the end we've had to abandon a few glazes because of blistering/pinhole issues.

it's fun trying to figure a glaze out but after you've exhausted every internet resource and you are tired of making excuses for that one blister that always shows up - it's time to let the glaze go. for a couple of firings anyway.

re-firing, in my experience, does not work. every glaze has it own personality so hopefully you have some success. we've only ever tried re-firing to the same temperature as the initial firing but we were only trying to fix the most severe cases.

long story short - don't get too attached to a dysfunctional glaze unless you really enjoy testing glazes.

p.s
i learned the hard way that a failing thermocouple will lead to over-firing will lead to blistering so careful your temperature isn't creeping up on you.

*p.p.s.
i really dislike blisters.

**please excuse my failure at reading comprehension. i'm guilty of not reading and understanding the entire thread before braving a reply. it was late - i was tired.

some glazes just refuse to get along.

/lurk

neilestrick, on 10 November 2012 - 12:26 PM, said:

How can I identify pinholes or blisters don't they somewhat appear the same? I really appreciate the information on the method used to resolve the two different situations.

In general, I would bisque everything to 04. Pinholes typically need a soak or higher firing. Blisters typically need a lower firing or the glaze needs to be stabilized with more clay and/or silica.