Most cone 6 gerstley recipes, if the content is not too large, can be adjusted
for frits. Ferro frits 3124,3134 and 3195 are all boron bearing frits.
As far as glazes go you have to decide what kind of work you want to produce
and what surface and colors you think would be appropriate for that work.
You can use ash or fake ash glazes for one look, transparent glossy glazes that
can be used alone of over slips for more depth and variation is another way to
go, or matt glazes or all of the above.
Oxidation glazes can have depth by layering, using slips underneath, etc.
Any or all of the above can give you a good body of work. You just have to put
in the time and start testing.
I just finished spending several days batching glaze tests and now have over 60
tiles that I'm getting ready for firing.
You just have to be willing to put in the hard time.
You are the only one who can give yourself the jump start. The web is filled
with glaze recipes, pictures of glazes and pots, etc.
One good base glaze can give you an unlimited number of colors to choose from.
Make sketches of the pots you want to make and then decide what claybody you
want to use and what kind of glaze you would want to see on those forms and
start testing.
As far as silica, I use 200 mesh just because I feel it's a bit safer than
dealing with finer, air born, silica particles of 400 mesh. The finer mesh will
melt sooner and often it is used because if a glaze is borderline crazing the
finer silica or amorphous silica can sometimes prevent that.
I'd rather alter the expansion of the glaze in most cases rather than resorting
to using finer silica.
Lastly, I think it's a mistake to think you have to make oxidation glazes look
like cone 10 reduction glazes. There is some wonderful work coming out of cone
6 oxidation and I just think it's waste of energy to try to make it something
it isn't. At best you can only expect a poor substitute for the most part.
You can get beautiful matts at cone 6 with firing down, which permits crystal
growth.
With cone 6 oxidation you have a vast color pallette to work with and with some
creative endeavors can get interesting looking work. Maybe incoroporate more
texture in your pieces and then those transparent glazes will pool beautifully,
giving them more depth and interest.
You just have to get in there and start working.
If you're using Randy's red you might want to test it since with all that
gerstley and high iron it might leach and may not do well over time in the
dishwasher. It's a glaze that may best be saved for non functional work that
won't be subjected to the harsh environment of the chemicals in a dishwasher.
You can do a quick vinegar test by putting some vinegar in part of a shallow
dish with this glaze and let it sit a couple of days and see if it changes
color. It's not a definitive test if it doesn't; but if it does, it shows you
that it is leaching and won't be food safe or dishwasher safe.

Regards,
June Perry
http://www.angelfire.com/art2/shambhalapottery/