nancylee Posted November 3, 2013 Report Share Posted November 3, 2013 Hi all, I bought a bag of dry clear glaze, 10 lbs. added 2 tablespoons bentonite, and 110 oz water. The glaze is settling into concrete on the bottom before I even finish mixing it! I am now up to about 10 tbsp. of bentonite. Something is definitely wrong here! Any ideas? Much thanks, Nancy Link to comment Share on other sites More sharing options...
Min Posted November 3, 2013 Report Share Posted November 3, 2013 I would try stirring in a little bit of saturated Epsom salts solution, tiny bit at a time until it behaves. I wouldn't add any more bentonite. (for clear glazes I use macaloid not bentonite as I have had speckling from bentonite, even with the white type) There is an excellent article on flocs, deflocs and thickeners here: http://www.claytimes.com/articles/glazeadjusting.html Min Link to comment Share on other sites More sharing options...
nancylee Posted November 3, 2013 Author Report Share Posted November 3, 2013 Hi Min, Thank you! I'll go look at that now, Nancy Link to comment Share on other sites More sharing options...
Iforgot Posted November 8, 2013 Report Share Posted November 8, 2013 You could also try adding CMC gum solution, a commercial suspension agent, or glycerin a tablespoon at a time. Darrel Link to comment Share on other sites More sharing options...
neilestrick Posted November 9, 2013 Report Share Posted November 9, 2013 I would stick with epsom salts. The problem with CMC is you often need a fair amount to do the job, and you end up with a glaze with a very high water content, which makes for thin application when dipping. The CMC will also get eaten away by bacteria since it is an organic material, sometimes in a matter of days, and it's difficult to add more to the glaze without first making a solution of it, which means you'll also be adding more water to the glaze and compounding the problem. If you do use it, put a tiny amount of copper carb into the glaze to act as a preservative, like 1/10 of 1%. It shouldn't show up in the glaze. But I'd go with the epsom salts. Cheap and effective. Link to comment Share on other sites More sharing options...
TJR Posted November 9, 2013 Report Share Posted November 9, 2013 I say stick with the Bentonite. You have hardly added any. You need about 3% of the weight of the dry material. Should be mixed in water first.Bentonite is a very plastic material. Works to suspend glazes. I use it all the time.If you add Epsom Salts, you are changing the electrolytes at a microscopic level. This causes the molecules to repel each other. Sounds like you don't have enough clay in your glaze Bentonite would solve this. I don't know how to convert pounds to grams in my head, otherwise I would tell you how much to add. TJR. Link to comment Share on other sites More sharing options...
PeterH Posted November 10, 2013 Report Share Posted November 10, 2013 I don't know how to convert pounds to grams in my head, otherwise I would tell you how much to add. Put something like 5 lbs in grams into Google. Regards, Peter Link to comment Share on other sites More sharing options...
Min Posted November 12, 2013 Report Share Posted November 12, 2013 The calcium in Calcium Chloride has the same +2 charge as the Magnesium in Magnesium Sulfate (Epsom Salts) but for some reason Calcium Chloride seems to work better in flocculating glazes. Pete Pinnell thinks so too. http://www.claytimes.com/articles/glazeadjusting.html True, but like Pinnell says: "The most common flocculants potters use are epsom salts (magnesium sulfate) and calcium chloride, though acids (such as muriatic acid, available from paint stores and pool supply houses) can also be used. Epsom salts work in most instances and can be found at just about any drug store or grocery store. Calcium chloride is a bit stronger (I prefer it), but a little harder to come by." I think we are getting down to a moot point, both work. Link to comment Share on other sites More sharing options...
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