Bubbles forming in glaze (BEFORE firing)

[Shaina Mahler]

Hello! This is driving me a little crazy. As I apply glaze, tiny bubbles immediately show up on the surface and create these little holes. It seems like air is coming up from the clay body. Is this normal? Will there be problems when I fire this? Anything I can do?

For more context: this is cone 5/6 clay bisque fired to cone 04. The glaze I’m using is Coyote (rhubarb). The glaze itself is pretty thick and the photo below is after two coats brushed on. 

Edited July 30, 2022 by Shaina Mahler

[Pres]

This topic or something vey close to it was discussed recently in this strand:

I hope this will help you with your problem. If not, please review your glazing process here so that folks might be able to help you more accurately. Please include things like thickness of the glaze you are using, you glazing technique (dipping, pouring etc), type of clay glazing and the bisquefire temp of you clay.  

best,

Pres

[Shaina Mahler]

12 minutes ago, Pres said:

This topic or something vey close to it was discussed recently in this strand:

I hope this will help you with your problem. If not, please review your glazing process here so that folks might be able to help you more accurately. Please include things like thickness of the glaze you are using, you glazing technique (dipping, pouring etc), type of clay glazing and the bisquefire temp of you clay.  

best,

Pres

Thank you! That helps a bit but I’d love to hear more thoughts if people have them. I edited my post to include more detail about the clay and my glazing process.

[Callie Beller Diesel]

The picture is worth 1000 words, thank you!

The little bubbles like that aren’t unexpected in a brushing glaze. From the looks of the online product description, it’s a fluid glaze, so they should heal over. 

[Bill Kielb]

5 hours ago, Shaina Mahler said:

Thank you! That helps a bit but I’d love to hear more thoughts if people have them. I edited my post to include more detail about the clay and my glazing process.

A couple thoughts
It would be fairly easy to test if wetting the body before your first glaze coat would solve this. It appears as the air is displaced from the pores of the bisque the glaze is too dry or not fluid enough to heal over. I have used premixed glazes in bottles as well that seemed to arrive in a variety of thicknesses. I would also test whether thinning this glaze to an ideal thickness will make a lot of this go away as well. As to whether it heals in the firing unfortunately is a trial thing as well, as some glazes do much better than others.

[Shaina Mahler]

Thanks so much for the responses everyone. So helpful. This particular glaze IS really thick so I’ll experiment with thinning it and cross my fingers that all goes well in the kiln.