Potters & Sculptors - Making Rock from Mud
This is what I use, (I claim no credit), it was shamelessly lifted from the net.
It's a really nice well behaved glaze for me; + 4% Tin Oxide will give you a creamy white.
20 Potash Feldspar
20 Ferro Frit 3134
Thanks so much. I'll try it out.
Digitalfire reports, "A down side to boron in certain glazes is that it combines with silica to form borosilicate crystals which can make an transparent glaze go somewhat cloudy." . . . "Al2O3 has a stiffening effect on the melt and helps prevent the crystals from growing. Use INSIGHT to hold or drop the SiO2 while increasing the Al2O3 until the crystals are inhibited."
I like the Glossy Base 1 in "Mastering Cone 6 Glazes" which does not have this problem, using a variety of fluxes with just 4.62% Boron from the Ferro Frit 3134.
|Glossy Base Glaze 1|
|20.0%||Feldspar G-200 Potash|
|20.0%||Ferro Frit 3134|
|20.0%||Kaolin - EPK|
The MC6 Glossy base recipe needs to be modified if you cannot buy G200 or if you are using Texas Talc. here are the adjustments - works great for me:
Glossy Base 1:
Custer Feldspar 23.5
Ferro Frit 3134 20.0
or using Minspar:
Minspar 200 (soda) 22.5
Ferro Frit 3134 19.5
Custer Feldspar 24.0 - the mine where Custer comes from has changed over time and doesn't test to what they print
Ferro Fri 3134 20.0
Talc 6.0 - texas talc
or with Minspar:
Minspar 200 (soda) 23.0
Ferro Fri 3134 20.0
Talc 6.0 - Texas Talc
A little late to this topic but I want to share my favorite cone 6 clear glaze recipe, from Ellen Currens.
50 gerstly borate
50 plastic vitrox clay
Beautiful clear that takes stains well, as with all transparents apply thinly. We mix this by the bucket full at the pottery
and find it very dependable.
Gerstley Borate makes a good substitute for man-made frits.
The resulting clear tends toward a warm yellowish tint. The man-made frits make a clear which tends toward a cool blue.
Plastic Vitrox Clay is an interesting product, sort of a kaolin which is actually a fairly low potassium feldspar with a touch of calcium. We have a 50 pound bag and haven't used it as much as I should.