How Long Do The Effects Of Epsom Salts For Flocculation Last?

[luhps]

As i understand it, for glazes that settle out to much, Epsom Salts can help with Flocculation, what I can't seem to find is how often one would have to add the epsom salts to maintain the effect.

I know it could be simply "as needed" and I could experiment on my own, but I like to know as much as possible before trying something.

 

Is it just a few days or a few months?

 

Thanks!

[High Bridge Pottery]

I have never had a glaze run out of epsom salts and start hard panning again. Don't know if it lasts indefinitely but I have never added again to a glaze. 

[neilestrick]

Unless something changes with the chemistry of the water, it should last forever. I suppose if solubles in the glaze material slowly leach out over time and deflocculate the glaze, then you could need to add more epsom salts, but I've never had to do that.

[luhps]

Unless something changes with the chemistry of the water, it should last forever. I suppose if solubles in the glaze material slowly leach out over time and deflocculate the glaze, then you could need to add more epsom salts, but I've never had to do that.

 

Thanks for the info.

 

Anything else I should know before doing this? such as, anything I shouldn't mix it with?

 

As for amount, I'm following this rule of thumb :

"create a saturated solution of Epsom salts by dissolving them in a cup of warm water until no more will dissolve. Then add this solution slowly and carefully to the glaze while continuously stirring the glaze. It should require less than approximately one teaspoon of Epsom salt solution per gallon of glaze." - https://www.bigceramicstore.com/info/ceramics/tips/tip3_glaze_settling.html

 

And to quote you in another thread Neil...

http://community.ceramicartsdaily.org/topic/3760-can-bentonite-and-epsom-salts-be-together-in-a-glaze/

Use about 2% bentonite and 1/2% epsom salts by dry weight. The bentonite should be mixed well with other other ingredients before adding water to keep it from clumping.

[High Bridge Pottery]

I think you need clay in the glaze for it to work so a glaze with no clay wouldn't gain any benefit. Only 50% sure about this statement   Thinking about it I did add 2% bentonite and 1% epsom salts to a pure whiting glaze to help, I should try without bentonite and see if there is any difference.

[neilestrick]

How much you'll need will ultimately depend on the glaze formula, and how thick the glaze is to start with. Making a solution and eyeballing it will work just fine, or if you're mixing a fresh batch then use the percentages.