Blister Fix?

[David F.]

I have used these glazes before without blisters so I'm pretty sure the problem is due to applying to thickly. Any one have a good solution?

see images below

 

[David F.]

Should have mentioned ...fired to cone 6 with a 45 min. hold and slow cool. also top shelf is worse than other shelves.

[neilestrick]

Cone 6 with a hold that long likely got you to cone 7 or 8, which means that glaze is over fired if it's a cone 6 glaze. That would account for the blistering. It appears to be an ash or fake ash rivulet type glaze, which tend to be fairly unstable- high in calcium, low in silica. If firing cooler doesn't fix it then try adding silica and/or alumina in small increments until it stabilizes. As some point it will affect the rivulet action, though.

[David F.]

Glaze is Steven Hill's "Hanna's Fake Ash". It seems to be difficult to get the ideal thickness. I had it turn out brown but with no ash effect before;probably because it was too thin.

[Min]

Glaze is Steven Hill's "Hanna's Fake Ash". It seems to be difficult to get the ideal thickness. I had it turn out brown but with no ash effect before;probably because it was too thin.

 

Excuse this if it's redundant but if you are using the recipe for Hanna's Fake Ash from Hill's cd it has a major typo. There is no silica in the recipe, if you use the cd recipe it is likely to be an ugly brown with not much rivulet effect. BTW the original version is a ^6-10 glaze,