Old Dawg, new trick!
I just
unloaded my first firing of Sweet Baby Jane and I quickly got busy glazed up
another load and she’s firing again tonight. I really hadn’t made pots for this
kiln so I was thankful to have a couple of boxes full of slab trays that Andrew
made for me during the summer. I couldn’t resist some temmoku- the glaze that
potter’s love and never sells. I got carried away with a cobalt blue glaze Jane
gave me. I was thinking of paying bills and remembered the motto- if it doesn’t
sell reglaze it blue and if it still doesn’t sell salt fire it.
One of the
many reasons I like the carbon trap glaze is that it does make the pot look wet
again. Wet pots especially freshly slipped ones are my favourite time in a pots
life. Because it looks wet it is hard to photograph so I just am showing some
close ups. It is dark, I’m tired and I’ll be up till 3:30, teach tomorrow,
meeting tomorrow night and then the gang arrives here for a 3 day marathon wood
firing. No rest for the wicked!
So the new
trick is how this kiln fires. The program Geil suggests for carbon trapping has
the kiln go into light reduction around
1650F. It doesn’t go to the extremes of pushing the damper in and having smoke
coming out every peep and around the door.
Something I used to do. It moves slowly up to medium reduction and
holding up to around 2200F. I was
talking to Jane on the phone at about this time and she asked “ Has it dropped
yet?” I didn’t quite get it, hung up and went out to check the kiln. There was
a green flame out the stack, and both peeps. Good back pressure and the gas had
been turned up and the damper opened. Oxyprobe
reading neutral to really light reduction. What the Sam Hell? I had always
fired all the way up to Cone 10 in reduction with the damper a whole lot
further in. Who am I to argue with a computer that is likely smarter than me. Well
the computer wins. The glaze is a nice smokey shino wth little mouse gray spots
of carbon trapping. This firing I still have the blues I've just tuned them down.
Comments
When we got our Geil kiln at school back in 2009 I started firing like we were taught in school, heavy smoke and flame coming out of every oriffice. I soon learned after getting an oxy-probe through a grant, that I could get quite good reduction with no smoke or flames coming out of the stack, just good back pressure at the spy holes. I then set the primary air disks on the burners open just to the with of two stacked popsicle sticks, drew lines every 1/8" on the damper and used 1/2 the gas pressure recommended by Geil. After getting to the top gas pressure I would use during the firing, the only adjustment I made was moving the damper in, then back out 1/4"! Damn fine kiln!
..... And the good don't need it Good firing Señor