Potters & Sculptors - Making Rock from Mud
I am not certain of the origin of this glaze but I got it from the Prince Albert Arts Center and I believe they got it from the Saskatoon Potter's Guild.
Custer Feldspar 22
Gerstley Borate 22
Neph Syen 22
Titanium Diox 2
Red Iron Oxide 3
Copper Carb 4
I sprayed the glaze, applying continuously and working around the piece until the glaze started to run. This gave me a somewhat thick coat which fired to a nice glossy brown with very funky green spots.
is this in an oxidizing, electric firing?
I fired this to cone 6 in a vented electric kiln. Thought this is a vey cool effect for a cone 6 oxidized firing! A thin coat gives a nice warm brown and thicker gives the speckles.
Once you get used to the conventions, basing everything on 100% makes increasing amounts very simple as for a 100 g test batch you use the same amounts, or you can increase to 500 g by multiplying all by 5 or to 1000 g by a factor of 10 or 1500 by factor of 15, etc. The items included in the 100% are a base glaze with colorants and modifiers listed separately so they can be changed if you want to try different colours or surfaces. I have a few glazes that give me a really cool effect such as spots and I can try to get the same effect in a different colour which gives me an infinite array of possibilities with just one base glaze. A great example of this is Gartside base from which I've gotten great effects such as tea dust, hare's fur, small spots, crystals, etc. I keep Gartside base mixed up dry and can test by weighing out 100 g and adding colorants and opacifiers. I also use 50 g amounts of base and add colorants by half (you need a very accurate scale with really small amounts) to see if I am in the ballpark of the effect I want to get, without using a lot of glaze materials. I have far to much garbage glaze as I really like to formulate and test glazes!
I hope this hasn't just further confused the issue for you but glaze chemistry is a huge field and I've only scratched the surface.
Thanks! I'll give it a try!
Has anyone tried reformulating this to use a frit instead of Gerstley Borate? Any suggestions on how to reformulate it. thanks.
Thank you so much for this recipe! I've only done a couple of test fires so far, but it is lovely!
The next 2 are Frogskin on the bottle & then I refired it in a bisque. Yep, that's all I did. jhp
Ive wanted to try this glaze since the first post on it. Add it to my list! nice pictures Jeff, and thanks for sharing Kathy.
I have done a little research since I posted these pics. It says that I used "Special Sauce" on the rim on the first one. I still don't remember what that is(No, it's not from McDonalds!). The second bottle says it was layered with Licorice, Waterfall Brown and Magic. The 3rd bottle which I refired in a bisque, is just layered with Magic. Magic is a glaze that the Ceramic Shop sells. Frogskin will go a little red when refired in a bisque, but not like you see when it was layered with Magic. I just reordered some more Magic & it is on sale in a 6 lb. bag dry. If you just want to try it, the 8 oz. wet is only $4.00. Not necessarily plugging the Ceramic Shop, but they do have some good glazes and you can buy them dry as well as wet. jhp