Vitreous engobes
These are great with colorants... I've had success adding Mason stains, etc.
(using Mason stain colorants in soda firings is probably best for a separate discussion)
If used alone, they are like a white-tan slip glaze (too much flux for good flashing).
I find them to be very versatile for leatherhard to bisque application. They fire to a nice satiny surface when used alone (but the colorants are generally more consistent when used under a glaze).
I'll post pics soon of these slips in action...colleen
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'A' (variation of Susan Peterson engobe)
Ball Clay 35
Whiting 10
Neph Sy 25
Flint 20
Lithium Carb 5
Borax 5 (Gerstley Borate or Frit substitute is easier)
Zircopax 5
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Wood Ash Engobe
Ball Clay 30
Talc 15
Wood Ash (unwashed) 20
Cornwall Stone 25
Gerstley Borate substitute 10 (or frit 3134)
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Wollastonite engobe
Variation of wood ash slip (the above slip is a little difficult to apply smoothly, so I'm trying wollastonite as a sub. for ash. I'm still tweaking to get the right clay:flux but it's promising...)
Talc 10
Wollastonite 25
Cornwall Stone 25
Frit 3134 10
Ball Clay 30
I don't know much about the techs of soda firing, but none of these slips are posted with a temperature. Is there only one temperature people fire to when soda firing-or would these slips be appropriate if going to cone 6 or cone 10?
the ones i posted i fire anywhere from cone 8- cone 12- depending on the firing. they should be fine at cone 6- the only concern would be that they are formulated to match or fit a cone 10 body- so you would want to test them to see how they fit a cone six body- and the depth of the flashing may not be as much at cone 6.
here are a few of my favorites, all of which i would recommend be mixed with distilled or purified water. i have lived and worked in different regions of the country in the last few years and had some hard vs. soft water issues. All recipes i have used on stoneware, Cone 10, salt , soda and wood. I mostly slip at leather hard, but Bauer, Titanium Yellow, and Silverman, will all work on bisque.
johnston flashing slip
grolleg 50
newman red fire clay 10
epk 10
neph sye 30
Orange to White Crackle
(for some reason this is in lbs, and adds up to 34?!)
Borax .75
zircopax .75
custer 3
calcined Kaolin 3
EPK 2.25
OM4 21.25
Silica 325 3