Sunday, May 26, 2013

One More Tidbit

Another helpful rule of thumb from Cushing's Handbook:

Very broadly: If the proportions (by molecular weight) of silica to alumina in a glaze in the range of 8-10, the glaze will probably be glossy and transparent.  This (and the next bits) does not account for which flux is used; a high proportion of magnesium (for example) used as a flux will cause the glaze to be matte regardless. The proportions of silica to alumina can go as high as 18 to 1.

If the proportions are in the neighborhood of 5-8 to 1, this will probably be a satin or waxy glaze. Depending on the flux.

If the proportions of silica to alumina are 1-5 to 1, this will likely be a stony matte glaze.

Charlotte Smith
We have yet another chance today to learn to dance in the rain, here in Maine. (A friend observed that we must be slow learners!) The pots that I left unwrapped all day yesterday and then overnight, are still too wet to trim. My plan is to throw some ^6 test pieces, now that I have a boatload of recipes to test, and to generate a boatload more recipes with my new toy.

1 comment:

Unknown said...

The weather seems like it's giving us the 40 days and 40 nights routine, eh?