Sunday, March 23, 2008

The elusive Waterfall Green Glaze

Call me persistent.

I've been working on and off for over a year trying to develop a green version of the Waterfall Brown glaze. It's a glaze developed by John Hesselberth and Ron Roy, and featured in their book - Mastering Cone 6 Glazes.

If you mix your own glazes and need help, or if you want to start doing so, I can't imagine a better book to get you started.

About my green tests, I've come up with so many versions of green, my studio is full of samples. I have a small piece of pegboard hanging right above my glaze mixing area, where all the samples are stored.

It's full.

Since I'm mostly trying to develop a green for use in my hand made tiles, I'll tell you a little about the test tiles I make.

I made a small jig that allows me to cut a half dozen rectangular tiles at once. This allows me to roll out a slab and cut six tiles in seconds. I also use a small circular cookie cutter for making small circular tiles. Sometimes, I even make small "tubes" of tile, similar to the cardboard center on a roll of paper towels, only much smaller. I make them roughly the size of a finger, which allows me to test dips in the glaze sample. This is really helpful for learning if a glaze drips during it's final glaze fire. See, I figure if I'm going to the trouble of mixing a 100 gram batch of a glaze, I might as well dip it on a few tiles, rather than just one. So I generally test a glaze on 3 different bisqued clay.

I tend to not add a lot of texture tiles I make for furniture, but still, I want to see how the glaze behaves over texture. So I'll occasionally stamp something in the clay, just to experiment a bit.

The tiles above show a green that's way too light, but the crystal pattern is strong and well formed, which is, besides the color, something I'm trying to achieve.

In the next two tests, I tweaked the colorants slightly, and while there are still some great patterns within these tiles, the color is off. It's much too light for what I'm hoping to achieve.

I'm getting closer to what I want with these two, but I still have to play with the colorants. I envision a hunter green glaze, and these are still a bit too bright. They're very nice, if you like teal versions.

Instead of using chrome to achieve green, I am using copper carbonate. It's beginning to make the green really pop out on these test tiles. I tested extensively with chrome, but nothing I did met my approval.

Switching to copper carbonate made the tiles much more pleasing, and put me on a better path for getting the color I want.

The tile below is still a little light, I'm hoping for DEEP green.

Now this is what I'm talking about!

I've now tested this version of the glaze three times, and each sample has given me consistent results. I like this color so much, I will probably use it on some of the sushi dinnerware sets that I make. But before that, I need to test it for it's resistance to acids.

It's a simple test, but it takes 3 days.

Basically, to test a glaze for it's resistance to acid, you soak it in something acidic for three days. In this case, I'll be using ordinary household white vinegar. Here's a "before" of the glaze I want to test. Check back in a few days and you'll see the "after" result. Keep your fingers crossed!


Anonymous said...

I really love your glaze test posts. I don't have a computer controller on my kiln so I have trouble making this glaze work for me, but am happy that you have finally done it. Great job.

Angela Davis said...

Jamie! Congratulations, the green is gorgeous. You are persistent and it has paid off well.

Amy said...

hey jamie,

that is a gorgeous glaze you have co-created!! are you sharing the recipe?? i'd call it jamie's waterfall green...forever!!

:) amy in oregon

Anonymous said...

Do you have the book, Mastering ^6 Glazes?

If so, you know the Waterfall "base" recipe for this glaze.

To make the green, I've added 12% Copper Carb and 1% Rutile.


Anonymous said...

I love your site. Love the green. persistance pays. I have actually started to experiment with this glaze. I have been using the waterfall brown with the licorice for a while now and love it for myself but it does not sell well for some reason that is beyond me. My waterfall white came out of the kiln today and is working o.k. but picks up the underlying color so I'll keep at it. Thanks again for your great site. One question, I have a recipe for waterfall light blue. Can't remember if it came from you and can't track it down in your blog. Can you reprint the recipe? Mine doesn't look right.
Thanks. Chris Galkin ( Rhode Island)

Jamie Y said...

Chris -

I have two blues, one is light, and one is vivid; I think you're talking about the light one. All the Waterfall recipes I've been working on use the same Waterfall base as in the book, but I add 5% Ball clay to decrease the running. So my base recipe adds up to 105, instead of 100.

For the light blue, I add are 5% RIO and 1% Rutile.

For the vivid blue, I add 4% Copper Carbonate and .5% Cobalt carbonate.

Hope this helps, would love to see pictures if you get some interesting results. Good luck,


Anonymous said...

Any idea if waterfall green and blue are food safe? Thanks

Wood It Is! said...

Good Question! I would contact John or Ron, who wrote the book on Mastering Cone Six Glazes and ask them. They're great at responding to e-mails.