Friday, December 31, 2010

Santa was good to me

I asked for a cheap hand held blender for Christmas and Santa delivered.

I read about using a hand held mixer for glazes online somewhere (John Britt?) and I thought it might work. Well today I used my new mixer for the first time. Hot damn Skippy it rocks.

Normally when I mix a batch of a test glaze I mix 300 grams in a small tupperware container. I run the glaze through an 80 mess sieve twice to mix it. It's a slow and messy process.

Today I stuck my new mixer into the text glaze turned it on and 30 seconds later the glaze was perfectly mixed with no mess at all. What would have taken me 20 minutes before took me less than a minute. And it was much cleaner.

If you mix glazes buy a hand held mixer. You will be happy.

Thank you Santa!

Wednesday, December 29, 2010

Another new glaze recipe

I have been gazing at work by Brother Thomas and Chun Wen Wang lately. Iron glazes can be so wonderful. They can be almost any color, clear, matte, crystalline. Just an amazing mineral.

So I started to think about iron yellows. Brother Thomas' influence. I haven't been able to find any good examples of an iron yellow for cone 6 oxidation online. I was scratching my head. I was surfing and googling and generally flailing blindly. As it happens sometimes the answer was right in front of me. Literally. Right in front of me was a platter I made last year, lorio ash, cone 6 oxidation and a beautiful yellow. The colorant? Iron. I just needed to tweak the recipe from being an ash glaze to being a normal stable glaze.

The original:

Alberta Slip 43.9
EPK 5.9
Whiting 29.6
Wood Ash 13.9
Grestely Borate 8
TiO2 6

The tweaked glaze:

Alberta Slip 53.9
EPK 5.9
Whiting 15
Grestely Borate 10.2
Silica 15
Red Iron Oxide 3
Titanium Dioxide 6

I will be testing this soon.

Tuesday, December 28, 2010

A new glaze to test

I am getting antsy to see the glaze tests I dd last week. I have to wait until next week to see them.
In the mean time I was looking for another black temmoku. I came across this recipe that is from Nigel Woods' great book:

Silica 20.5
Wollastonite 18.5
Custer 19
EPK 14.7
Ball Clay 14.7
Iron oxide 9
Mang dioxide 3.2
Cobalt carb 0.5

This is a cone 10 glaze. So I tweaked it:

Silica 23
Wollastonite 21
Neph Syn 22
EPK 17
Grestely Borate 17
Iron oxide 9
Mang carb 3.2
Cobalt carb 0.5

I changed the manganese dioxide to carbonate as 3.2 percent of manganese dioxide makes me nervous. I added borate to help drop the melting point and removed some clay for the same reason. Also swapped the feldspar from custer to neph syn. then normalized the recipe to 100 without colorants.

I also have been reading a lot about Brother Thomas. His work is truly inspiring. I saw some of his pots have manganese over temmoku. I am going to mix up some mang. washes with grestely borate.

Saturday, December 18, 2010

Tests done

So I spent some time getting my tests ready.

I have a line test of bailey's red (cone 6). Line testing from 5%-14% RIO.

I am also testing a new clear. No line test just a single tile. If it melts and doesn't craze it's a winner.

A test tile of my cone 6 Obsidian #3. This is derived from a Richard Aerni recipe:

Alberta Slip 75
F3134 25
Cobalt Carb 5

Next is a new black temmoku.

Nepheline Syenite 14.4
EPK 19.9
Dolomite 18.3
Whiting 7.5
Silica 39.9
Lithium Carbonate 2
Red Iron Oxide 9

On top of these tests I made test tiles of some of my normal glazes - lorio ash, nuka, and a chrome/tin pink.

I'll post pictures when I get them - probably after Jan 1.

Oh and I was pretty bummed about my last glaze batch. Everything was over fired. I think one of the kilns at the new studio is over firing. The bisqued test tiles were also over fired. I had to toss out about 10 of them as they wouldn't take any glaze - they had partially vitrified. So I am not starting over with my normal cone 6 glazes. I am talking to the powers that be at the new studio about fixing the kiln instead.

Wednesday, December 15, 2010

Great glaze resource

I ran across this site today:

Super awesomesauce.

Have fun!

Monday, December 13, 2010

Pop quiz time

Well test time at least.

The glazes I used at my last studio didn't transfer well to my latest studio, so it's time to test. I decided to do it right. I made up about three dozen test tiles and I am starting with a blank sheet of paper and what colors I want. The first thing I want is a good black temmoku. I don't want Val's Temmoku Gold. I don't want the crystals, I want a smooth, glossy pitch black temmoku.

So I pulled out all my books (I have a bunch of glaze books) and started reading - why are most cone 6 temmokus full of crystals? How can I get a beautiful fat black tenmmoku at cone 6? I had tried before but failed. I found the answer this time. One little paragraph tucked away in Michael Bailey's "Oriental Glazes". The crystals form when the glaze is low in alumina (duh, like all those glazes that have intentional crystals). So the key is to flux down a cone 10 temmoku while keeping the clay content level with the cone 10 formula AND not overloading the glaze with calcium. So my flux options are adding grestely borate, possibly lithium, replacing the feldspar with neph syn, maybe even adding a couple parts barium carb.

On top of that I have a couple of line tests lined up - trying to figure out what the hell happened to my iron red and what recipe will work in these kilns.

I'll post the actual recipe for the temmoku once I get one that I like.