Dipping glaze turned into sludge…tips on thinning?

[JRW]

Hello,

 

In my feverish early days of making pottery I bought several 5-gallon buckets of commercial glaze from a potter who was moving away. I then let them sit in my studio for at least three years, never stirring them (I know, that was a mistake). I just opened one and it had become a fairly firm sludge with a couple inches of clear liquid on top. 

I tried mixing it using a jiffy mixer, which didn’t really work because it got gunked up and didn’t seem to break apart the big chunks. I then used an immersion blender, which helped more, but there simply isn’t enough water.

I know I can ask the manufacturer for the ideal specific gravity, but any tips on how to blend this into a workable glaze again? Do I just add distilled water and keep mixing with the jiffy mixer and immersion blender? Those don’t seem to dredge the thicker layers underneath. I’ve heard Epsom salts could help? How much?  
 

I’m hoping there’s a way to do this that won’t take hours.
 

thanks!

 

[Min]

Glazes can deflocculate over time, sounds like this might be what happened. Soluble materials, such as sodium, can in time leach out of nepheline syenite, spars, frits  etc and cause hardpanning.  Mixing it up more frequently wouldn’t have prevented this. 

I’ld pour the liquid off the top of the glaze, don’t throw it out, and cut out the hardpanned glaze out of the bucket with a loop tool. Remix it  with the liquid you poured off plus some water first and a small amount of epsom salts solution and see if that fixes it. Add enough water to get it back to the specific gravity glaze manufacturer recommends. Might need to add bentonite slurry if Epsom salts solution alone isn’t doing the trick. Given that we don’t know how much clay and/or bentonite is in the recipe it might not need it. 

If you do use bentonite you need to slake it in water until it absorbs the water, it will take a few hours. 

John Britt video of the process here if it helps,

https://youtu.be/0S_gbVkq378

[JRW]

5 hours ago, Min said:

Glazes can deflocculate over time, sounds like this might be what happened. Soluble materials, such as sodium, can in time leach out of nepheline syenite, spars, frits  etc and cause hardpanning.  Mixing it up more frequently wouldn’t have prevented this. 

I’ld pour the liquid off the top of the glaze, don’t throw it out, and cut out the hardpanned glaze out of the bucket with a loop tool. Remix it  with the liquid you poured off plus some water first and a small amount of epsom salts solution and see if that fixes it. Add enough water to get it back to the specific gravity glaze manufacturer recommends. Might need to add bentonite slurry if Epsom salts solution alone isn’t doing the trick. Given that we don’t know how much clay and/or bentonite is in the recipe it might not need it. 

If you do use bentonite you need to slake it in water until it absorbs the water, it will take a few hours. 

John Britt video of the process here if it helps,

https://youtu.be/0S_gbVkq378

Thank you so much! I’ll try this.

[Callie Beller Diesel]

From entirely too much experience scraping up hardpanned glazes from freezing them over the winter:

Trying to mix it with a jiffy mixer or a blender, or anything with a motor is only going to impact it harder, and you’ll be there for DAYS.  The fastest way is to either do the loop tool thing like Min said, or to go at it with a plain old wire whisk. Gently agitate the whisk into the solid layer, and shake it into clumps. It’s incredibly counterintuitive, but the clumps that you loosen up this way are far more inclined to re-disperse. 

[JRW]

1 hour ago, Callie Beller Diesel said:

From entirely too much experience scraping up hardpanned glazes from freezing them over the winter:

Trying to mix it with a jiffy mixer or a blender, or anything with a motor is only going to impact it harder, and you’ll be there for DAYS.  The fastest way is to either do the loop tool thing like Min said, or to go at it with a plain old wire whisk. Gently agitate the whisk into the solid layer, and shake it into clumps. It’s incredibly counterintuitive, but the clumps that you loosen up this way are far more inclined to re-disperse. 

Thank you!