Defining success
May. 10th, 2019 07:06 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
offcntrWell, it's been three days since I unloaded the test firing. I can finally talk about it without flinching. It was a qualified success.
We reached temperature, top and bottom largely even. We didn't take much more time than usual, and the gas usage was right on average, 34 units.
The reduction was awful.
I've talked it over with Linda, who fires next, suggested some ways to make it better. Reduce the primary air (air through the burners, controlled by opening and closing a threaded shutter), maybe use the peephole in the chimney as a passive damper. Don says you really need to be able to smell the unburned gas, which is way more reduction than I'm used to in the inside kiln. Whatever happens, it's out of my hands now.
The firing wasn't a total disaster. I had lots of white pots in my stuff, little or no copper red in anyone else's. But Nicole's cobalt crawling glaze mugs looked good, Jon's servers and some of his mugs were fine, and Linda said her two mugs and fox vase, while not ideal, were certainly sellable. Don's two test bowls looked normal to me, but Brian got mostly cobalt in his bowls, though there was a little copper red inside two. A couple of my pots, near the top back, showed the opposite effect, over-reduction giving a peachy bloom to my white base glaze. Go figure.
There was one spot of perfect reduction in the entire kiln, on the back left side, just above the bag wall. Just big enough for one pot; guess which one?
Squirrel!
We reached temperature, top and bottom largely even. We didn't take much more time than usual, and the gas usage was right on average, 34 units.
The reduction was awful.
I've talked it over with Linda, who fires next, suggested some ways to make it better. Reduce the primary air (air through the burners, controlled by opening and closing a threaded shutter), maybe use the peephole in the chimney as a passive damper. Don says you really need to be able to smell the unburned gas, which is way more reduction than I'm used to in the inside kiln. Whatever happens, it's out of my hands now.
The firing wasn't a total disaster. I had lots of white pots in my stuff, little or no copper red in anyone else's. But Nicole's cobalt crawling glaze mugs looked good, Jon's servers and some of his mugs were fine, and Linda said her two mugs and fox vase, while not ideal, were certainly sellable. Don's two test bowls looked normal to me, but Brian got mostly cobalt in his bowls, though there was a little copper red inside two. A couple of my pots, near the top back, showed the opposite effect, over-reduction giving a peachy bloom to my white base glaze. Go figure.
There was one spot of perfect reduction in the entire kiln, on the back left side, just above the bag wall. Just big enough for one pot; guess which one?
Squirrel!