Wednesday, January 26, 2011

A Big Step Forward

I gotta say, I'm pretty excited.
Did a rather methodical ware firing Jan 24th and reached several milestones.
First, I completely cleaned and washed my kiln and shelves - ground the shelves down to bare shelf, vacuumed out the kiln, ground all the posts clean and level...

I worked with 2 main forms - yunomi and 3-sided bowls - and 5 glazes:

Crystal Matte

Neph Sy  50
Dolomite  20
EPK  20
Bone Ash  10
Copper OX  1.5
Rutile  5

Matte Black

Barnard Slip  80
EPK   10
Custer 10
Cobalt Ox  1

Oharata Red

Ball Clay   6
Custer Spar   48
Silica   22
Talc   6
Whiting   6
Bone Ash   12
Red Iron Ox   10
Bentonite   3


Whiting   20
Custer  35
Ball Clay  15
Silica  30
Red Iron Oxide  10


From Michael Coffee
Custer Feldspar    36
Silica   30
Whiting   22
OM-4   6
Wood Ash (unwashed)   3
Talc   2
Bone Ash   2

Everything was single-fired, and the kiln was held at 500f  and 1800f each, for one hour. Reduction was started after the 1800f soak and carried out to cone 10/11. The kiln was then slowly cooled of about an hour to 2000f and then shut off.
I used an iron rich stoneware clay from Quyle Kilns.

I had some issues with glazes running and sticking to the shelves, but I think that's surmountable.
This is the first load I've fired that had NO breakage, no S-cracking, no warping, and no real glaze flaws (ie: pinholing, crazing, shivering...).
This is also the first firing that I am excited about - I mean really excited about!
I see lots of potential in my glazes - so much so I can't wait to get back to throwing so I have something to put said glazes on!

I did have some unexpected results, but I think I understand why.
One other thing...I'm playing with photographing my ware for Etsy and these are shot on my mantelpiece. I'm not trying to present them as something particularly grand or special, just wanted to experiment a bit.
Lets get to it shall we?


Like everything in this load, these are lined with the Barnard slip-based Black Matte.
The outside was first brushed with a thinish coat of Oaharata Red, and then sprayed with the Crystal Matte.

I tried to be sparing with the second glaze near the bottom - spraying it lightly twice, while spraying the rim area 3 times and fairly heavily.

Regardless, I got lots of running and shelf-sticking-to. The bowls were all placed in the middle and upper part of the kiln. I've never had the Oharata run, and I did have a bit of running with just the Crystal matte on testing, so I need to see about stiffening it up (I thought the Oharata might do that. In the glaze tests, there really wasn't much difference between the tiles with or without the Oharata. Also, in the glaze testing, the crystals were turquoise, which I assume is because they were not reduced as much? Anyhow, I'm really excited about this glaze!


Lined with the Black Matte, this 3-cup bowl was brushed with a thin layer of Tenmoku and then a single, fairly thick layer of Nuka was poured over it.

I'm really pleased with this!
I'm not getting the lovely all-over blue loveliness  that Michael Coffee showed, and I'm hoping one day I can get that, but hey - there's nothing wrong with this result!

Is the plural of yunomi yunomi or yunomis???
Lets start with the Nuka ones.
Nuka over Tenmoku

Again, lined with the Black Matte.
I sort of was anticipating some dripping on these, so there's an area on the lower portion of each cup that just has the Black Matte on it.

Well, its drippy and fun and has lots of interest.
I personally am not a fan of drippiness in glazes, but this one's getting lots of ooohs and aaahs amongst my pals.

Both the Tenmoku and Nuka were brushed on.

Nuka over Red Iron Oxide

This is more interesting and eye-pleasing in real life.
I just wanted to see what would happen.
Its a little pinholey - probably because it was brushed on a little too sparingly.
Its not pleasing to the touch.

Nuka over Oharata

Yeah - I think this is my favorite.
Love the mossy green with the turquoise rivulettes (hope I spelled that right - my spell checker doesn't know).

Hardly any dripping.
Crystal Matte over Oharata Red

Wacky huh?
This is the exact same glaze combo and application technique as the bowls at the top of the page.

The only difference is that all of these were on the lowest kiln shelf, and the shelf above them was pretty big and may have created something of a saggar atmosphere on this shelf.
That's the only thing I can think of.

There were about 8 of these on that bottom shelf - all pretty well packed in.
Maybe 3/4 of an inch of space in between each of them.
Or perhaps because they were all crammed together there on the bottom (where my burners come up through the floor of the kiln), they didn't get the advantages of a nice slow cool and so didn't form crystals?

But why so shiny when the bowls were such a lovely matte?

Its a puzzle to me.
I don't hate them, but I sure don't love them either.
I do think they are trying to teach me something though...

Soap Dish

I'm SO inspired by Keith Phillips!

This little soap dish surely echoes his work, but hopefully I've made it my own.

This is the Crystal matte sprayed over a sloppily applied Oharata Red.

It was on the topmost shelf of the kiln, with a small shelf between it and the flue opening.

So there ya go!
I'm back at the wheel tomorrow. I think I may be finding my voice!
Thanks for stopping know your comments are always appreciated.


Monday, January 10, 2011

18 Glazes!

I'm spending January working on developing a glaze palette that is consistent and feels like my voice.
I almost feel like when I have it nailed down, I may shift my form a bit to follow it.
Bass-ackwards I'm sure.

I have about 4 good, consistent glazes now - a crystaline gold, a lovely Tenmoku, an iron red and both a glossy and matte white.
I just want a little somethin' somethin' in there too.
Anyway, this test was 18 different glazes, at cone 10 reduction.
Everything was single-fired, and the kiln was held at 500f  and 1800f each, for one hour. Reduction was started after the 1800f soak and carried out to cone 10/11. The kiln was then slowly cooled of about an hour to 2000f and then shut off.
Each glaze was applied to 4 tiles (in the order they'll appear in the photos):

  1. over both Red Iron Oxide and Rutile washes
  2. 1/2/3 dip on white stoneware
  3. 1/2/3 dip on iron rich stoneware
  4. over iron red (Ohata) glaze.
Unless otherwise indicated, all glazes started with the following base
 (from "the Potter's Palette" by Constant and Ogden):
  • Potash Feldspar                  50
  • Dolomite                             20
  • EPK                                   20
  • Bone Ash                           10
Click on any image to see it full size.
As always, comments and input are greatly appreciated!

Glaze #1a

Base Glaze plus 1.5% copper oxide.

Glaze #1b

Base Glaze plus copper oxide 1.5% and rutile 5%

Glaze #1c

Base Glaze plus copper oxide 1.5% and tin oxide 5%

Glaze #2a

Base Glaze plus cobalt oxide 1%

Glaze #2b

Base Glaze plus cobalt oxide 1% and vanadium pentoxide 3%

Glaze #2c

Base Glaze plus cobalt oxide 1% and tin oxide 5%

Glaze #3a

Base Glaze plus rutile 15%

glaze #3b

Base Glaze plus rutile 15% and chrome oxide .25%

Glaze #3c

Base Glaze plus rutile 15% and tin oxide 5%

Glaze #4a

Base Glaze plus vanadium pentoxide 6%

Glaze #4b

Base Glaze plus vanadium pentoxide 6% and red iron oxide 3%

Glaze #4c

Base Glaze plus vanadium pentoxide 6% and rutile 5%

Fire Yellow Redux

From ClayUtah forums.

Custer Feldspar           50
EPK                           50
Dolomite                     25
Whiting                       10
Tin Oxide                     5.5
Bone Ash                     8
Red Iron Oxide            1
Rutile                           2

Blindingly Bright Green

(from ClayUtah forums)
Oh dear - this is just so wrong. Looked so good in the pic too! But I see I left out one ingredient, so I'll try it again...

Ball Clay                                     10
Whiting (accidentally omitted)      20
Silica                                           20
Custer Feldspar                          40
Copper Carbonate                       .5
Chrome Oxide                             2

Choy Celedon

(from John Britt's "The Complete Guide to High Fire Glaze")

Custer Feldspar                 50
Silica                                 28
Whiting                               6
EPK                                   4
Barium Carbonate             12
Red Iron Oxide                   2

Barnard Slip

Barnard Slip        80
EPK                   10
Rutile                  10

Shaner Oribe

(From John Britt's "The Complete Guide to High Fire Glaze" )

Custer Feldspar          31
Whiting                      22.1
Silica                          25.3
EPK                          12.6
Talc                             7.9
Bone Ash                     1.1
Copper Carbonate       5.2

John's Red

(from John Britt's "The Complete Guide to High Fire Glaze")
Not sure what happened here, except it called for frit 3134 and I only had 3124.

Custer Feldspar     48.2
Whiting                  13.6
Silica                     15.5
EPK                       5.5
Frit 3134
(subbed 3124)        9.1
Talc                        3.6
Zinc oxide               4.5
Tin oxide                 1.2
Copper Carbonate     .8
Bentonite                   1

Well, there ya go. Some complete failures, but some really exciting possibilities too!
Next week, I'll be testing the same glazes, and maybe a few more, in an oxidation firing.
Stay tuned...