Castroville Fake Ash: Glaze mistake


Here is an example of how mistakes turn into glazes. We were recently mixing up glazes for a workshop at Castroville Clay in Texas and I mixed up the recipe incorrectly.  Here is the recipe:

FRASER CELADON
Cone 10 Reduction
34.00   G-200 Potash Feldspar
21.00   Silica
27.00   Wollastonite
15.00   Grolleg Kaolin
3.00     Talc 
   
0.50     Red Iron Oxide 

So I messed up by adding Whiting instead of Wollastonite. The good news is that I had the mix ticket and had made all appropriate check marks so we knew what happened. So now the glaze was :

Castroville Fake Ash 
Cone 10 Reduction
34.00   G-200 Potash Feldspar
21.00   Silica
27.00   Whiting
15.00   Grolleg Kaolin
3.00     Talc 
   
5.00     Red Iron Oxide 

But instead of just throwing it out we decided to  add some iron to see if we could get a nice color sort of randomly. So we added 2% red iron in the second tiles and then added 5% in the right tile.  With 5% iron it  is a really nice glaze!

Notice how it crazes in the first tile, then less as you add iron, and with 5% the crazing appears to stop. Now we would have to test a bit more to be certain but it is a good start.  

Another option would be to run a progression of iron to get the full range of colors available, or to run a progression of whiting from 20 % - 30% with the 5% iron in the base and see how that changes the glaze and see if a different amount may be more to our liking.  

Glaze on !








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