Thursday, February 4, 2010

Single Fire Glazing!

Well, yesterday I did my first single-fire glaze firing.
I think I'm a fan...

After getting a better tank from the propane company, I was finally able to reach cone 9 1/2, which was great. I was getting really discouraged.
To begin with, I just used my current compliment of glazes to see how they would work (well for the most part). I glazed bone dry ware and let everything dry for several days before firing.

In the pic, the larger tiles in the background are Laguna 1/2 & 1/2 (porcelain and stoneware), and the shotglasses are Quyle Kilns Sandstone Buff.

The firing took about 14 hours - probably longer than it really needed to - bt that included a 90 minute candling at 500f. To 1000f I went *really* slowly. Just a very light reduction. The flue was open to 1500f, then at 3/4 open to about 2100f, then 1/2 open through to cone 9 1/2 (I couldn't quite get cone 10, but I think I know what to do about that). No cool-down or anything.
So...

Nuka 1
This is my first attempt at making up a glaze. I surely wasn't expecting results this nice! Its really simply, but I'm really pleased with it. Dipped once, then dipped 1/2 way again.
My wood ash was mostly pine, with some oak.

Redart ........33.3
Silica...........33.3
Wood Ash...33.3
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Cobalt Ox.......2
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Nuka 2
Needs some work.
This started out as John Britt's recipe from PMI Jan 2010
I like what it did where it stayed, but it crawled and shrank like crazy.
I know its because I didn't have any Cornwall Stone, so I tried to substitute. I do think its worth pursuing.

Potash Feldspar..........30
Silica.........................28.5
Wood Ash.................41.5
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Yellow Salt
Yeah, right.
OK - this one is my fault. This glaze is from "Complete Guide to High fire Glazes" by John Britt. I actually have this glaze (same batch) on a couple of bowls and its an opaque oatmealy glaze - not really yellow (because I messed up the batch by not blending the ingredients dry first, and I used yellow FeO instead of red), but nice.
Obviously I should have double-dipped.
I'm still in search of a nice warm yellow...


Neph Sy..........................71.6
Ball Clay...........................4.8
Dolomite..........................23.6
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Red FeO (I used yellow).....1.1
Zircopax..........................17.9
Bentonite...........................4 (I omitted because I couldn't find mine)
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Fat Celadon
This really is not the same glaze as above!
it is a nice stable glaze - not very spectacular on its own.
I thought it might like this iron-rich clay body, but I do think its nicer on a white body, and in heavy reduction.
But I love it over my gold glaze (as you'll see)!

I do want to find a nicer celedon, but I don't want to use Barium Carbonate, so I need to do a little more playing.

Sorry, can't find the recipe right now.

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Horrible Icky Blue
Man I hate this glaze!
Don't know where I got the recipe. Its 1 dimensional, uninteresting and just has no life. I have a few gallons left and really only use it as a liner glaze. I think its stain based.
Anyway, I was looking for a better blue and now I think I've found it in my little Nuka glaze.

If you're a FaceBooker, you can see just how ugly it is here:
http://www.facebook.com/photo.php?pid=280377&id=1409288159

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Ohata Red
OK - your basic iron saturate glaze. Its a little dark, but I really like it. Its all speckled with black - sort of oil spot looking.
In the group photo at the top of the page, its on the dog bowl on the right.
Here it is with Nuka 2 on top.
Pretty cool huh?





And here it is with Nuka 1 over it.









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Gary's Gold
One of my favorite glazes.
I got this recipe from Mo potter Gary Kelsey.
It works in ox or red and with care has an almost crystaline gold look.
I love it on its own, but throw some of that Fat Celedon over it and its really wonderful!

This tile is the 1/2 & 1/2 clay body, single dipped and then dipped again 1/2 way.


And here it is on an iron rich stoneware, with the Fat Celedon on the rim

So, all-in-all this has been a very successful first attempt at single-firing.
I am encouraged and excited and have some pretty clear ideas on where I need to go next as far as my technique and palette.

CMCK