Sunday, May 15, 2011

Tying up some Loose Ends and The Glaze Learning Curve

Before I dive into posting about the next creative path I've undertaken, I just wanted to tie up some loose end.

First and foremost, my pugmill. Have I mentioned lately how much I love my Peter Pugger VPM-9?

I know, right? If you've been following my ordeal with my pug mill, those are probably words you never thought I'd write. Well Peter Pugger FINALLY introduced a stainless steel pug mill and I upgraded. I've had it for almost 2 months now and there's absolutely no trace of those evil chunkies that plagued me for so long. This means my production has been a lot smoother. I'm no longer throwing away pieces or making tons of seconds. A HUGE source of my frustration has been eliminated! Yay!

And next, my glazes.
I've been working on my sand colored matte glaze again - still doing some fine tuning. I managed to narrow down my search by taking my matte base with 0.5% nickel and 3% tin in it and studying it for a while. While a nice color, I still wanted it less creamy beige and more greyed. Given that my slate matte glaze is nickel and cobalt, I figured that if I added some cobalt to the sand matte, I could push this glaze to the grey side. But the question became HOW MUCH cobalt to add. I ran a series of tests, using 25%, 50% and 75% of the cobalt that goes into my slate matte glaze, based on the ratio of nickel in the sand glaze. In the case of 25% of the cobalt, 0.04% is SMALL! But...I am getting closer.

I'll run one more series of tests on this glaze and am confident that I'll get what I want. The 25% was sill a bit too grey, so I'll bump it down to 20%, 15% and 10%. I may even eliminate the tin. It doesn't seem to dissolve nicely into my matte and I end up with teeny-tiny white spots. Without a ball mill, I can't see this getting any better, so I figure I'll just try without. 

And speaking of my matte glaze....

You may recall the issues I had been having with this glaze that I'm too stubborn to stop using. Turns out, I need some practice using those Epsom Salts.

They change the viscosity of the glaze, making it appear thicker than it actually is. So I need to resist the urge to add water! I should know better by now, but I added a LOT of water to get the glaze to the consistency I was used to working with. I would have saved a whole kiln load of pots if I had double checked the specific gravity of the glaze. I had even taken the time to write it on the outside of the bucket when I got the glaze thickness to where I was happiest with the results. I guess I'll just have to make a hydrometer to make things easier for myself.

Ahhh, to live and learn. Good thing it's easy to refire that glaze. I managed to salvage some of the work.

Oh- and the tweaking continues with my striped bowl!

So I'm anxious to share with you the other pieces I have been working on and thought I'd leave you with a teaser! Enjoy!


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