MERKLEYS on fri 11 sep 98
Linda the name says it all. In forming articles using the damp dust
method just enough water, in the form of a mist, is added to powdered
clay,so that if you squeeze the mixture hard it forms a lump. If done
properly you should be able to crumble the lump back again,that is to
say ,there should not be enough water in it to form permanent lumps. I
think twelve percent or there abouts. I would think the less water the
less shrinkage, this method is used by commercial tile manufacturers, I
think. Just made some kiln shelves useing this method, the only problem
is they tend to be fragile until fired, and I had a hell of a time
getting them out of the mould. I used a fifty fifty grog fireclay mix
which was ramed into a twenty by twenty inch by one inch thick solid
mold, next time will make it so the sides come off instead of trying to
force the shelve out of the mould. The best way to dampen the clay grog
mix was to lay it out on a plywood sheet about one inch(or less) thick
and spray with a plant spritzer. Just keep mixing the concoction until
you get the proper amount of water in it. Hope this is some help to you.
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