THE FIRING

NOTE: 
NEARLY ALL THE PIECES IN THIS FIRING HAD THE INITIAL COAT OF GLAZE BRUSHED ON. 
I USED EITHER A CALLIGRAPHY OR HAKE BRUSH (or both!)

the clear glaze coating many of them was dipped on.


The cone 6 firing is underway! I mixed up the Strontium Opal Blue glaze this morning, looking like a Mad Scientist or the Spawn of Darth Vader with my dust mask on to screen out any particles of glaze ingredients that might have gotten airborn.  I added one cup of water to the unmixed dry ingredients, then stirred them thoroughly.  I strained it four times thoroughly through a little 80 mesh screen I bought at the Ceramic Store.  Then I let it sit for a bit while I did a few things.  I went back in to the studio after about an hour and stirred up the glaze in case anything had settled.  I labeled it with my hot pink duct tape and taped the glaze recipe on it with clear packaging tape.  Its also dated.  I made a new area for mixed glazes on the big TV shelf that I stole for the studio to put large pieces on.  It's empty, since I don't make large pieces.  The shelf for the VCR and DVD players is where I put the large glass jar of glaze.  I got the glass jars from a trash bucket at the Morgan ranch where Ken's mom, now deceased, saved hundreds of glass jars with lids to put things in!  Sometimes I wonder if George and I should just sell everything and retire at the Morgan Ranch -- but then, I love it here too much, and I can't go barefoot there everywhere like I can on our two acres here.


I used a haki brush to brush on the glaze, layer after layer, on the little noodle bowl I made.  Its really WAAAAAAAAY too small for a noodle bowl if you are Asian, but I am not, so I don't care that its too little.  Its cute!


I took some other pieces I'd put slip or glaze on, plus an ugly white Ladymug demitasse that never got to cone 6 in its reduction firing, and off Hitomi and I went to the Lee College studio to do some work.  I dipped a little jarrito mug with Indian designs I drew and painted on it with slip into the clear midrange glaze after stirring it thoroughly. I took a shelf out because I'd forgotton to add the kilnsitter cone -- Paula Rutledge helped me do that.  I reloaded the shelves I had to take out, and then went to relax until Jen Herzberg, my professor, could come help me load the kiln.


Thatls when I got sidetracked.  Jen was doing a throwing demo and I was watching it through a little gap in the tables when I finally realized I could stand up and go sit close and watch it.  So I did that.  Then Phil got into one of his narrative modes and started telling tall Texas true tales about Aggies and  such while Jen threw.  We all enjoyed watching Jen throw and listening to Phil's yarns.  After about an hour, I realized I'd forgotton all about my original reason for coming -- to program the kiln and fire it!


Jen finished her throwing demo, did an errand then came back to help me program the kiln.  I went and got the kiln log and she filled it out after checking about how to program a cool down soak.  I had already put in a cone 8 cone in the kiln sitter, so that even if the kiln got real hot, it wouldn't trip the sitter and shut down the kiln, aborting the cooling soak.


Then I programmed it.  I'll have to go get my notes, but it was a pretty simple ramp with just four parts:


Ramp 1 -- 150 degrees an hour until it reaches 250 F


Ramp 2 -- Then 400 degrees an hour until it reaches 1982 F


Ramp 3 -- Then 100 degrees an hour until it reaches cone 6 (2232 I think. Lemme check)


Ramp 4 -- Then cool as fast as the kiln will drop naturally until it reaches 1472. THEN an hour soak


THE END


Then open it when the kiln cools to about 130 to 100 degrees.  I estimated about a 22 hour firing.  Jen checked my work in the kiln chart and agreed with my assessment. I began the firing at abougt 3:30 pm or so today.


Som I will probably be able to open the kiln Friday morning and unload it! Yaaaay!


A couple of things I am worried about -- first, I wonder if I got the clear coat of glaze on the little Indian jarrito too think.  It goes translucent when its on too thick.  I counted to 30 when I dipped it and as I drew it out I was wondering if I was supposed to count to three Mississippi instead of 30 with no Mississipis (Southern way of measuring seconds.  It takes one second to say a number and then say Mississippi after the number.  In other words, it takes 3 seconds to say "one Mississippi, twoMississippi, thee Mississippi"


I also wonder about the cracking white glaze on the bowl I did gloss white, and on the interior of a "candy apple red" cup I glazed and gave a white interior. The candy apple red I substituted dark red mason stain instead of deep crimson.  I did not have any deep crimson at home -- it is a really deep burgundy red -- but dark red is RED red.   We shall see.


I am wondering how all the glazes and slips I made will turn out.


I made the following glazes to test in this firing
Noxema Blue -- cone 6

Smooth satin coloration.  Brushed on with calligraphy brush 3 or more coats. A very nice stable glaze. does not move.  

custer feldspar---------------48.3	483
wollastonite------------------23.2	232
kaoliN------------------------11.1	111
gerstley borate--------------10.1	101
flint--------------------------4.5	45
cobalt carbonate-----------2.8	28

COMMENT FROM PERSON WHO GAVE THIS RECIPE, USED AT THE UNIVERSITY WHERE HE WORKS
DJ,
It is stable, and does not need to be thick.  Good luck.   I throw test tiles as a big ring in an upside-down "t" shape, then cut the ring into pieces about an inch wide when leather hard.  If the upright, glazed section runs, it collects on the wide, flat base projections. 
JQ James Q. Jacobs   Professor of Archaeology and Anthropology
jqjacobs@yahoo.com

Back to DJ's blog: 

However, I made another much nicer cobalt blue using the gloss white cone 6 recipe with cobalt carbonate rather than zircopax colorant added.  The depth from the gloss gave it remarkable beauty.

see images below

COBALT GLOSS CONE 6 -- TWO DIFFERENT TEABOWLS

GLOSS BASE WITH 2.5 GRAMS OF COBALT ADDED 

INSTEAD OF ZIRCOPAX

Nepy Sy	35
Silica	21
EPK	10
Whiting	8
Gerstley Borate	18

Using the same glaze recipe as above,  I measured out 5 tablespoons of the base gloss and added 3 quarter teaspoons of praseodymium yellow mason stain to it.  The yellow came out picture perfect, no crazing, with a very nice gloss.

GLOSS BASE WITH PRAESEODIMIUM YELLOW ADDED 

Nepy Sy	35
Silica	21
EPK	10
Whiting	8
Gerstley Borate	18

GLOSS BASE WITH TURQUOISE MASON STAIN ADDED 

This turquoise, like all the other glazes, was brushed on with a calligraphy brush with 3 or more layers on the outside.  I did less on the inside to see what would happen and the coverage is not good. The turquoise color is perfectly smooth and a very nice rich turquoise -- better than the turquoise Helmer slip dipped in clear gloss  cone 6.

Nepy Sy	35
Silica	21
EPK	10
Whiting	8
Gerstley Borate	18

Candy Apple Red -- cone 6

Candy Apple Red -- Satin to matte surface.  
Very clean red -- can be brushed on very thick. Does not move.  Very nice bright primary red.  Dark Red Mason stain 6021 is the added glaze colorant in this mug shot. (heh heh. mug shot!)

By far the best result from the several reds -- both commercial and those mixed by me -- in the 9.22.2010 Kiln Firing.

(NOTE:I used dark red mason stain 6021 in my glaze instead of deep crimson in original recipe)

Silica 31.0	62
Neph SY 26	52
Whiting 19	38
EPK 19	38
Gerstley Borate 5	10
Dark Red Mason Stain 6021 6 grams	12

&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

AMACO VELVET BRIGHT RED UNDERGLAZE 

-- SEVERAL COATS, DIPPED IN CONE 6 CLEAR GLOSS

I was very surprised that Amaco's gorgeous red slip performed less well than the candy apple red glaze that I mixed up.  But it did.  The tendency of the cone 6 clear gloss to go translucent did not help.  Plus this damn stuff is $31 a pint and is too expensive to even look at!


&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&

AMACO SNAPDRAGON RED UNDERGLAZE

I brushed the underglaze on greenware and bisqued it.  It came out so smooth and beautiful -- a very odd texture for underglaze, and yet, not quite a glaze feel to it.  Then when I brushed the clear gloss on it, a crackle pattern appeared all over it that was in no way apparent in the underglaze.  It fired a little weirdly with uneven coloration. As a stand alone color with a semimatte sheen, the snapdragon would be a lovely color on its own.  don't know how well it would work on ware used for food.

HELMER SLIP WITH DARK RED MASON STAIN 6021 ADDED

DIPPED IN CLEAR CONE 6 GLOSS

Dark red slip made with the Helmar white slip I made. This one is a claybody with not so much grog in it.  It crazed a lot. I measured 5 tablespoons of Helmer slip plus 5 quarter teaspoons of dark red mason stain 6021. I did a second teabowl on a groggy claybody, and the glaze over the slip did not craze at all on it.  So,the groggy clay cuts down on the shrinkage and helps the glaze fit better, apparently.
The color came out a tad salmon and the clear glaze went slightly translucent in places.

CLOSE UP OF CRAZING

HELMER SLIP BASE FOR GREENWARE

brushed on very thick with calligraphy brush

GOLD ART  25.77

FIRE CLAY 20.62
KENTUCKY OM#4   25.77
CUSTER   15.46
HELMER KAOLIN  10.31
SILICA    2.06
   TOTAL   99.99
ZIRCOPAX     10

Strontium Opal Blue -- cone 6

from Sanky database downloaded 8.18.2010
beautiful delicate periwinkle gloss.  Care must be taken to put on at least 3 to 4 coats or more by brushing.  If dipped, probably 3 seconds is fine.  MAYBE 2 dipped coats.  Moves slightly.  Putting it on thin results in see-through patches to clay beneath.

37.8 Custer Feldspar	75.6 Custer Feldspar
24.9 silica	49.8 silica
22.8 borate,Gerstley	45.6 Gerstley Borate
11.2 calcium carbonate	22.4 calcium carbonate
3.1 strontium carbonate	6.2 strontium carbonate
3 rutile, 0.4 cobalt carbonate	6 rutile, 0.8 cobalt carbonate

I made a turquoise slip also using the Helmer white slip for greenware.  It's the same as Ike's White, only I added Helmer Kaolin to it instead of grolleg.  It did not craze at all.

Helmer Slip

GOLD ART  25.77
FIRE CLAY 20.62
KENTUCKY OM#4   25.77
CUSTER   15.46
HELMER KAOLIN  10.31
SILICA    2.06
   TOTAL   99.99
ZIRCOPAX     10

5 tablespoons Helmer slip.  4 1/4 teaspoons turquoise mason stain.

At any rate, I should have a variety of ways to create the colors of bowls Laszlo has requested, and also, hopefully have a good blue to line Mari's blue monster mug with -- Noxema blue.


Here are some beauties and beasts that I made


Kudos to the person who discovered that Cone 6 Ohata dipped first and then dipped in Floating blue makes a totally kickass combination! Click on the mug for a full view! The glaze texture is well worth it!

Here's a little Indian style mug that was underglazed with Lana Wilson white slip, and then painted with Amaco underglazes -- Teddy Bear Brow, Mahogany Brown, light red and turquoise. I dipped it in the clear gloss and it went on perfectly and fired crystal clear -- just gorgeous.

HERE'S A MUG DIPPED IN ROY ROY LICORICE 2 ON THE OUTSIDE AND GLOSS WHITE ON THE RIM AND INSIDE.  I got the Ron Roy's Licorice 2 glaze on it WAAAAAAAAAAAAAAY too thick

It's a very nice glaze combination and works well toether, but I'll just have to not dip it so long the next time.  This is the only piece out of all of the above that was dipped.  Everything else was brushed using a calligraphy or hake brush.

Well, that's all the detailed stuff I am going to write right now.
much love
DJ


PS -- this clock is 2 hours off on this blog.  It is really 8:39 pm here in Texas.