I am planing to add water to mine and see what happens. I also have not fired in years and I have boxes of Duncan glazes. If nothing else we can add the dried glaze to new glazes and use them like crystals. Have fun getting back into firing. I am too.

Reviving an old post just for fun.

A small amount of Epsom salts (1/4 teaspoon) dissolved in hot water, then added to the mix. Id have to google the link I found it in for exact ratio.
Stir, let sit, strain through a sieve, repeat. It works!
(Just don't use too much magnesium or it can cause glazes to over run.)

My pottery teacher says glazes never go bad, just add water. I see the original question was asked 3-1/2 years ago, they're probably dryer than ever.

Glad I found this thread. Your teacher makes sense since it is just the water that evaporated out of the jar I would think. I have some I am going to try it on. But what would the Epsom salts do for it???? thanks! Rosie

the Epson salts act as an emulsifier. They recommend only a very small amount (google it and you'll get some recipes, I haven't done this in a while), but it does help declumb the glaze. Just don't use too much or the glaze will run.

You may still have to filter out some of the bad clumps...or just let them add to the finish!

Just add water and stir stir stir. They do this every couple years at the senior center ceramics class.

Id buy all the dried up paints and glazes 3374593704

I just googled "how to declump ceramic glaze with epsom salts" and got a whole bunch of information! Rosie