Thursday, April 23, 2009

the blues.

I've finally found my blue! Some other vapor firing potters out there may be thinking I speak heresy but at least it's an ash glaze, right? I've been trying to find a soft blue for some time now. I've tried several ways to get it without using cobalt but between the iron in the ash and in the clay that clearly wasn't going to work(though it does hold some promise on porcelain.) The other problem I encountered was that I only needed fractions of a percent when using cobalt and when you're mixing 100gram test batches that is not so easy or accurate. My solution was to mix up a 10000 gram batch(5gal bucket) and start with 1/10%(10g) cobalt and that was spot on the first time. The only drawback is that cobalt is so powerful it eliminates many of those little variations you get in an ash glaze. It usually likes to break brown on a sharp edge and I'm not seeing that happen, perhaps they're just not any edges sharp enough on this piece. Who knows what this will do in the wood kiln.


I've also made some headway on an ash based tenmoku, I think I just have a few more tests to get it where I want it.
So long for now.

11 comments:

Jerry said...

That's a sweet blue ash glaze. Very nice. When do we get to see how it comes out of the wood kiln?

Collin said...

That's a nice glaze even if it is blue!

brandon phillips said...

firing may 1st, lord willing.

Judy Shreve said...

I love the blues . . . and your is definitely a sweet one -- an ash temmoku -- that sounds intriguing.

Hollis Engley said...

Lovely blue, Brandon. Was the original a simple ash celadon?

brandon phillips said...

yeah, its' 442(spar/ash/ball). of course the type of ash makes a huge difference, i use mesquite. normally i add about 1% iron for a nice green. this one is .1% cobalt carb. sometimes the simplest solution is the best.

Michael Kline said...

oooo, .1% is just right. It's awesome on that texture too.

jimgottuso said...

man... that's a teenincy bit of cobalt, which is good considering the price

ang said...

you've started me thinking about playing with my ash glaze...it's way runny and i like the softness of your blue, kinda chun...and kinda grey i like it..

Amy said...

great shade of blue--- and that form! wish your work was at the smithsonian craft show this week.

ladyofclay said...

very nice, calm, subtle, beachy...

thanks for your comments on teapot making. I watched the videos a few times and have made 3 since and I can see an improvement already.
Colleen