Front stack
Soda Firing 3-13-23
The Fifth Kiln Firing is full for the first time. We have 17 participants. The kiln held about 290 pots. We got hard cone 6 everywhere except the very, very front of the kiln near the door. We put in 2 pounds of soda dissolved into 1.5 gals of water. We sprayed the soda right in at the end as the back of the kiln got hotter and we did not want to overfire. When we unloaded cone 6’s throughout the kiln were down.
We fired in a neutral atmosphere. We deciphered this by a small flame that licked out the top peep. when we removed the peep the flame would come out and then recede and stay within the kiln. The bottom peep never had a flame coming out. There were some flurries of reduction on the Turquoise glaze as well as the sea green.
Good dispersement of soda throughout the kiln. When spraying in the bottom peeps, next time let’s try and aim up and straight in. We shut the kiln down immediately after firing as all the cone 6’s we could see (4) were down. Ryan, Anika, Chris, Emily, and Terri helped soda!
Kiln Log
It is overcast and still at the start of the firing. Dark and chilly.
No breeze at all to blow out the burners - very nice! one blower would not start at first. I gave it a lil tap with a hammer and it moved a little. So I pushed it manually and then it started. Maybe it is getting a little rusty in this damp weather.
7:00am - both pilots lit
7:30am - both burners are lit with air on low, damper at 1/4”
8:30am - burners stopped back burning and are efficiently heating the kiln. bumped up both burners a little. Damper at 1/2”. The top is 250 degrees hotter than the bottom. This will even out over time.
9:00am - bumped up gas and air both burners to 1#/ air quarter turn up > dial up to 2pm
10am - 841ºF=T1, bumped both burners to 2# gas/ air dial straight up at 12noon, damper at 1”
11am - 1061ºF = T1: holding gas and air where they are at. the T2 is having a little trouble staying consistent in its reading. Right now top and bottom are still reading about 200 degrees different, with the bottom being cooler.
12pm - 1180 = T1: gas up to 2.5#, air at 3/4, damper at 1#, difference between T1 & T2 157 degrees.
So the bottom is catching up.
1:00pm - 1312 = T1. The bottom is 130 degrees behind and climbing/ leveling out.
Gas upto 3#, Damper 1.5”, Air on Full, Red hot top and bottom.
2:00pm - 1425 = T1. Bottom 92 degrees behind. pulled damper 1/4” out to 1 3/4”
Everything else is the same.
2:30pm - Opened damper to 2 1/2”. Kiln seemed to be slowing (although it is evening out).
3:00pm - 1536 = T1, bottom 72 degrees behind. upped gas to 3.5” and opened the damper to 3.5”.
4:00pm - 1638 = T1, 63 degrees difference. upped gas to 4# and damper to 4.5”
5:00pm - 1717 = T1, 26 degrees apart, holding gas as is, opened damper to 5”
6:00pm - 1833 = T1. 9 degrees difference, holding gas at 4#, damper is pretty wide open.
7:00pm - 1942 = T1, 10 degrees different Cone 1 (2088ºF) going top and bottom, damper opened 1/2” further. It’s hanging out pretty far! Still gaining 100º an hour.
8:00pm - 2029 = T1, 17 degrees different. The damper was pulled out a bit more to keep it neutral and climbing. small flame out the top peep.
9:00pm - 2094 = T1, 16 degrees apart. Cone five bending top
10:00 - 2151 - T1, we looked at the back cones and the cone six guard cones in the back of the kiln were down! Yikes! the front cones were 5-bending. So we decided to spray in soda and then turn off the kilns. It was so fun!!! Chris, Ryan, Anika, Emily, Terri, and Deb were present for the soda with a visit from Rachel as well. Thanks to everyone for your help and checking in on the kiln.
When we added the soda it cooled the kiln down by about 50 degrees. We finished up at about 10:20 and closed up all the ports. Hurrah!
The peak temp will be somewhere around 2200ºF/ or Cone 6
Cones Used 03, 1, 5, 6, 7
