This bowl below has an ash glaze on it, I may have sprayed it on too thick, not sure, it didn't blister when I tested it in a previous firing. Nothing else in the kiln was blistered.
On one item I used the same glaze around the rim and it's fine so I don't think it was fired too fast, but maybe it was too fast for this glaze at thickness.
Any suggestions for a future cure is what I'm looking for, I want to keep the runs but lose the blisters (if anything can be done with this bowl it may be worth a try, but I'm not expecting much in that respect).
Glaze is Val Cushing G4 Ash :-
Washed ash (pine) - 50
Ger.Bor - - - - -20 (I subbed Standard Borax Frit)
Whiting - - - - - - - 12
China Clay - - - - - - 8
Flint - - - - - - - -- - 10
Cob. Carb - - - - - - 1
Cop Carb. -- - -- - -6
Sprayed over a light coat of Strontium CM Warm and also a Pearly white glaze just to the central area.
Electric ^6 @100°C p/h <1100°C - @ 75°C p/h <1210°C and a 15 minute hold. Natural cool down.