Ron Collins on tue 9 oct 01
Dont laugh at me, but I vitrified my porcelain tests at cone 6 by adding =
jade powder to my basic 25% of each 4 porcelain plus 5% talc recipe.. =
Without the jade, just plain, the absorption was about 4-5%--won't work, =
the talc wasn't enough to bring it down to cone 6, but with jade added, =
I could never measure a difference in the weight (but my tests were =
small test pieces, so there is room for error,)...made it more buff =
colored, but no dark impuries...and has a nice sheen...what good stuff =
for colored clay/no glaze work. By adding fine volcanic river residue =
also, the color is nice charcoal sheen, which would be nice for the =
colored clay work too, and it's free. So, they should work together as =
colored porcelains, or at least to show students how to do patterning, =
thanks to Vince.... .It has become increasingly important to me to work =
with only what is available in this country, even though I have a bodega =
full of mason stains, frit and oxides, etc. Also, additions to a low =
fire chalky talc/ball clay blend trying things such as wood ash, soda =
ash, crushed glass, mica and other things that are free here has also =
given interesting results, trying to increase the vitrification some, =
and the jade works well there too, but better if it also has the wood =
ashes, and even better with some mica in it also, but the texure is =
crappy, and the color freckled with the mica. I only mix additions in =
to what I am using at the moment, as I am sure if the clay sits, the =
character of it would change. I was only working with pinch pots, just =
to make experimental pieces to try out the clays. This approach is not =
for anyone else, particularly. I don't think anyone really has an =
interest, but here, I have to do things differently. I cannot use =
materials in clays that must be imported, i.e., neph sye or frit....they =
weigh too much to be practical for how much one needs for claymaking, =
and people here can't afford to order such.....I have just despised =
working at low temperatures--mainly the porosity of it all, and the =
frustration of functional work not being truly functional, being so =
glaze dependent. I am hoping to introduce in November, when Lowell =
comes, a good high fire porcelain or porcelain/like body and a =
stoneware one, that will work well in the kiln he will be casting here. =
Also a more vitrified body for low fire, even though it may be breaking =
the rules of good "claymakingmanship". As far as the crushed =
glass/cullet, I had a 400 lb roller cast that Lowell says, if I sweep =
the floor, and put the fractured glass on the floor, it will crush the =
glass and hopefully other things too. I have not used it yet, but am =
anxious to try it on obsidian, which is volcanic glass, of which I can =
get plenty, just for the fun of it, to see if there is a difference =
between it and bottle glass. Like Joyce Lee, I don't get much =
sleep.....it just can't be legal to have had this much fun after 25 =
years of clay, and still can't sleep because of the lure of the =
studio......by the way, did about 20 cone 6 glaze tests, along with a =
bunch of clay tests, mostly from clayart....Teal Blue, found in John =
Hesselberth's site, is a beautiful one over porcelain/types (but 59% =
imported materials).....Alisa's Frosty is my white pick....beautiful and =
fat (60% imported materials)...but for "cheap" glazes requiring minimal =
imports, the winner there is Deep Green Glaze by Milt Friedly, CM, Nov. =
1991, which is:
23.6 Whiting
45.5 Custer spar (subbed Guatemalan unknown type fleldspatho)
21.8 Ball Clay
9.1 Flint-used #305
Additions were imported:--12.4%---will try other local substitutions to =
base glaze, then imports=3D0
Zinc oxide 9.1
Cobalt carb. 0.25
Copper carb 3
Burke's Celedon, from Clayart, was cheaper (6.9% imports in additions), =
and a lovely smooth melt, but it
crazed when thicker-don't use near as much copper as it says =
to....It's really nice though and may try other local =
additions...........sorry to be so boring, but I had to tell =
someone....Melinda Collins, Antigua, Guatemala ps...Floating Blue was =
everyone's pick, but it's out--79% imports !!
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