Thursday, April 7, 2011

Wet to Dry

Clayclubbers, Do any of you know of anything you can add to a wet glaze mixture to reduce wet to dry shrinkage? I have buckets (and buckets) of scrap glaze, Slopadon (a very nice, olive celadoney glaze in cone 6 electric) that shrinks and cracks a lot after I apply it to bisque, and later there are tiny, but annoying, bits of crawling out of the glaze firing. I'm thinking there is a fair amount of clay in there (I put slips and sigs into Slopadon, too) which made me just think maybe green glazing could be the answer. Any suggestions for chemical additions? Thanks!


John Britt said...


See if you can mix it well and then take a cup out and add some deflocculant to it. Not to much. Then see if it applies better. Sometimes with all that stuff in there it either flocculates or deflocculates. It it flakes off/ cracks after it is dry it is usually flocculated. (and this can cause crawling.

Alex Matisse said...

I green glaze everything and generally my glazes have about 20 -30% clay and 5% bentonite. I would try green glazing with the slopodon and see what happens. try leather hard, inside first, then let it dry back to leather hard, (usually a few hours) and do the outside.


mikpo said...

Hard to tell without the formula, but you might try calcining a bunch of the clay you are using in the formula and using this--50% more or less--as part of the clay component.

ronan kyle peterson said...

thanks y'all, ill try the deflocculation test and the green glazing. i could make the adjustments if i had a recipe to work from, but these buckets contain all the glazes, etc. i wash off and clean up during my glaze and slipping, and terra sigging cycles, mostly cone 03 and cone 6, probably 20-30 different recipes. its hard for me to throw anything away, and hearing about Warren McKenzie's Shop Floor Blue and seeing Shawn Ireland's Blue Scrap Glaze only validated my, we'll call it, resourcefulness. Will keep y'all posted!