search  current discussion  categories  materials - misc 

cmc reputation of spoiling

updated fri 26 sep 03

 

Bonnie Staffel on thu 25 sep 03


"Vee Gum Cer is macaloid with CMC thickener, which I do not use because
it spoils because of the CMC."

In a post yesterday, the above was said about the spoilage of CMC. I have
been using CMC for as long as it was available to the potter. I use it to
harden my Cone 8-10 glaze and it also deflocculates (flocculates?) it so
that I do not have to stir at all during the dipping process of my glazes.
The feldspar does not go into a hard cake in the bottom of the tub. Never,
never has my glaze spoiled. I make up a big 50# batch that lasts me several
months, summer or winter, never any spoiling. My proportion is 1/2 of 1% of
the total weight of the glaze ingredients. When weighing out the
ingredients, I dry mix it with kaolin and use hot water for the batch. This
way the CMC slakes quickly and does its work.

I believe I have written this in before that there must be some organic
matter other than CMC which is causing the spoilage.

Thanks for listening. I have moved everything out of my studio into storage
until I get the movers to put it in my new studio space.

Regards, Bonnie Staffel of Charlevoix, MI.
http://pws.chartermi.net/~bstaffel/