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Glaze Mixing Goof Up


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#1 Deb B

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Posted 11 December 2010 - 11:13 AM

OOPS!
I recently mixed a 5 gallon bucket of Randy's Red ^5-6 and inadvertently used Custer Feldspar instead of Kona (F-4),,,,
it came out a very translucent ugly brown vs the characteristic brick red. Is there anything I can now add to fix it?
Or should I just dump it out and start over?


Kona (F-4) Feldspar -- 20%
Gerstley Borate -- 31%
EPK -- 5%
Talc -- 14%
Silica -- 30%
-------------------------
100%

Iron Oxide 15%
Bentonite 2%

#2 Marcia Selsor

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Posted 11 December 2010 - 11:29 AM

I think you'll have to start over. F-4 is a soda Feldspar and Custer and G-200 are potash feldspars. They real impact the glaze character significantly.
I think you'd have to go a long way to figure out how to save the batch. I'd start over for Randy's Red. Do tests with the bad batch to come up with some decent looking liners. Maybe add an opacifier and more colorants or leave it translucent and add colorants. Don't throw it out, just modify.
It is not going to ever be Randy's red, but you could get something interesting with it. Some of my favorite glazes were screw ups. I am still mixing them because I know where I screwed up. It is good to always keep notes when mixing.
Marcia

#3 Deb B

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Posted 11 December 2010 - 01:20 PM

I think you'll have to start over. F-4 is a soda Feldspar and Custer and G-200 are potash feldspars. They real impact the glaze character significantly.
I think you'd have to go a long way to figure out how to save the batch. I'd start over for Randy's Red. Do tests with the bad batch to come up with some decent looking liners. Maybe add an opacifier and more colorants or leave it translucent and add colorants. Don't throw it out, just modify.
It is not going to ever be Randy's red, but you could get something interesting with it. Some of my favorite glazes were screw ups. I am still mixing them because I know where I screwed up. It is good to always keep notes when mixing.
Marcia


Thanks Marcia, that's kind of what I was thinking too. I like the idea of adding an opacifier and more colorants just to see what happens. I'll probably do it in smaller batches rather than the entire 5 gallon bucket. I have a very nice cone 10 blue glaze that I added the wrong oxide to and turned out to be a beautiful blue!




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