I'm rather proud of these!
Stepped cup in red clay:
Grogged red clay, layered glazes, wax-resist decoration
Stoneware Whisky Cups with Snow Glaze:
Thrown & carved/altered brown stoneware with varied surface decoration.
Carved tea bowl with Snow Glaze:
Carved winter tea bowl in buff-colored stoneware, snow glaze, wax resist "windows" and carved texture.
Black pitcher, "Bled Foam":
Black basaltware pitcher, thrown & altered, foam glaze with iron bleeding.
These are beautiful, especially for a beginner! Make me some!
ReplyDeleteI hope you realize that you're very talented. The pottery arts are awaiting your first showing.
ReplyDeleteInteresting way of doing that foot. I kinda like it, and it will prevent the bottom from sagging if its thinner. I might have to try that some time.
ReplyDeleteWith your textured stuff, you might want more flux in the glaze. It should do some interesting things. Just glaze thinner near the foot, and thicker at the rim.
Also, you might want to try some scraffito stuff with a slip or a glaze that does not move much.
I need to get back on the wheel more.. filling that kiln is taking way too long. :(
Keep working on it!
With your textured stuff, you might want more flux in the glaze. It should do some interesting things. Just glaze thinner near the foot, and thicker at the rim.
ReplyDeleteThese aren't the glazes I formulated; they're commercial glazes. Can I mix in some frit, do you think? I was thinking of adding some F69 or 3249 to the white glaze to control the crazing, but I don't know how much to add. How much would you suggest for the texture glazes?
I have a couple of really runny commercial glazes, but they run so much they leave no color behind them them sometimes. They do ok layered over other glazes, but I need to learn how to better control their effects.
Also, you might want to try some scraffito stuff with a slip or a glaze that does not move much.
Funny you mention it: I planned to do some contrasting slip sgraffitto soon to practice. I don't have a natural eye/hand for that process.
Get back on that wheel! And start posting pics of finished stuff.
Well... the white looks a bit suspicious to me. Like it's underfired, yet it's crazed, so maybe it's just supposed to be matte.
ReplyDeleteCrazing happens when the glaze and clay body don't expand or contract at the same rate, usually the glaze shrinks more than the claybody, and the tension eventually causes the crackle. Sometimes you can get around it by raw glazing, which promotes more interaction between the glaze and body.
Some glazes are supposed to do that, but alotta people think its a bad thing. I'm undecided, since sometimes I think crazing looks nice. Also... alot of glazes will craze after using them for teaware, because of the thermal shock of hot water.
I'm not really a glaze wizard and probably might not have alot more experience than you. But since you asked for a suggestion, I'd say try spodumene. It's a lithium source which is a pretty good midfire choice, and it should reduce shrinkage as well, which might stop your crazing. Also, lithium makes colors brighter, and shouldn't really change the whiteness if that's what you're going for. It's also alot cheaper than pure lithium carb.
Walt,
ReplyDeleteAfter poking around a bit more, I did a flatware scratch test on the white, and it does scratch, albeit lightly, which leads me to believe it's just a bit underfired.
So far, I have three leads: a high magnesium frit (3249/F69), addition of 5% silica, and your suggestion to up the lithium. Thankfully, this glaze is cheap, so i'll probably buy three 1-pound bags and test it out. I'll call it a loss of none of this works and learn to live with the crazing. The good features of the glaze are good enough I'd still use it.
¡Science!
Would lithium help a runny glaze run less? I've been told to add EPK to up the alumina content. Thoughts?
Jason,
ReplyDeleteIs there a way to patch terracotta that's shattered in a million pieces?
Imen
Imen:
ReplyDeleteAll the king's horses and all the king's men?
Seriously though, not that i know of, other than glue and patience. :(
Can I still have all the King's men and horses for other use? :P
ReplyDeleteI don't think glue will work in high heat. How about concrete or some sort of dry wall paste?
Ah, you mean to ask if you could fire the piece again in a kiln? That can't be done for stoneware, cuz the paste would shrink away from the shards. I don't know about terra cotta though; at terra cotta's lower temperatures maybe a paste could work. but if the piece is burnished it's possible the burnishing could burn off...?
ReplyDeletetry searching potters.org for an answer. if there's none, i'll ask on the pottery forums for u.
b3: Lithium is a strong flux. I use to modify high fire recipe's to midfire. EPK is basically alumina, which is a refractory. Silica is also refractory, and either will make things melt less.
ReplyDeleteImen: you can't fuse a cracked piece. Sometimes you can fill in a crack with ground fireclays, and if you're lucky you can make a small bridge on like, a carved piece. But those rescues are usually glazed over, and it's pretty much just the glaze holding it together.