Soda Firing 4-27-24

The 11th Kiln Firing is full load evenly spaced throughout the kiln. I added a one-inch post to the floor as a first layer to keep all the pots on a kiln shelf. When we had pots on directly on the floor they melted down and stuck bad.

Tiny shifts to remember: I added two more small posts (kept the ones added last time) within spaces in the bag wall to help the heat move up instead of through the bag wall. I continued to use posts along the bag wall to start the first stack. Last time we finished the firing around 5pm.

Kiln Log = Temps are for the Top of the Kiln.

Details from the firing will be logged here each hour. The link to this firing will be posted on Clay Q&A
Cones in our cone packs 012, 010, 06, 1, 4, 5, 6, 7

6:45pm - Lit south burner to fire overnight.
7:00pm - 72º F after 15 minutes. It took about 15 minutes to dial the burner in so there was no sputtering and had a nice blue flame.
8:00pm - 312º the gas is below 1# so not reading on the gauge yet. damper at 1”, Air on low.
9:00pm - 508ºF, Gas bumped to 1# one burner on. (candling overnight with one burner)
10:00pm - 848º, Gas at 1#, put the rest of the soda peep bricks in, some were not in and I did not notice at first. Damper at 1”. Air at Low.
3:00am - 1294º, steady climb.
This morning it is grey and a little windy. The weather forecast is for clouds all day.
6:00am - 1403ºF, top red, bottom dull red.
Lit second burner - pushed to 1#, 1st/ South burner pushed to 2#
Leaving damper at 0.5#, Air at medium-high/ marker pointing straight up, air on south/ low on 2nd burner. Bottom at 1123ºF
7:00am - 1435º (small climb on top), bottom 1260 (137º climb on the bottom)
Bumped north burner to 1#, holding south burner at 2#
Air and damper are the same.
8:00am - 1525ºF Top/ 1416ºF Bottom (109º difference)
9:00am - 1635ºF Top/ 1568ºF Bottom (67º difference).
012 cone is down on the top/bottom. We are a little ahead of the 10th Kiln’s firing schedule. Waiting for 012 on top and 010’s to bend to start body reduction. I am holding everything where it is for the moment.
9:30am - 1672º/1622º - body reduction started.
010 down top/ bending bottom. lots of back pressure. Flame out of the bottom peek.
10:00am - 1652º/ 1667º - body reduction over. It slowed down the kiln, got the bottom hotter, and made our clay bodies toasty. Damper opened back up to 2” gas at 2# both sides. Temp climb will likely resume : )
11:00am - 1741º Top/ 1779º Bottom hotter! - Opened up the gas tp 3#, Damper to 2.5” Air on high.
We are in cruising mode now.
12:00 NOON - 1931º top/ 1921º bottom.
Cone 1 is bending top/ not moving on the bottom. Both C06’s are down.
Damper at 3.5”, Gas at 3#, Air on high.
We will likely soda in 3-5 hours, that is a first guess.
1:00pm 2000º Top/ 1998º Bottom. The kiln is evening out! Good news.
Cone 1’s are down top and bottom. The kiln is climbing around 70 degrees an hour.
So that will put us at soda time right around 3:15pm.
Holding everything as is = Damper at 3.5”, Gas at 3#, Air on high.
Again, this is just a guess. Often the kiln slows down the hotter it gets.
Check the 2pm posting for more sure projections : )
FYI = Last firing we added soda around 2164ºF
2:00pm - 2080º Top/ 2084º Bottom - even temps!!!
Cone four is bending on the bottom. Everything is holding. No changes to gas, air, damper.
I would guess we will soda in 1.5 hours at 3:30pm (give or take)!
Yipppeeeee!
3:00pm - 2142º Top/ 2157ºF Bottom
Cone five and six getting soft on top and bottom
Soda likely in 10-15 minutes.
3:30pm - 2167ºF Top / 2176ºF Bottom - Time for Soda, both cone 6’s top/bottom are soft. Side peeps are not soft yet. Sprayed in 3 pounds of soda in 2 gallons of water. The kiln cooled by about 40 degrees or 8 degrees with every round of spraying. Five rounds of spraying with 10-second busts in all the peeps and front ports. The kiln cooled to 2125 on top. We held the kiln until it reached 2170 and shut it down!
Lots of help spraying in soda from Sarah, Mandy, Chris, James, Emily, n Deb : )
Thanks everyone!

Charting the Kilns Progress!

THE Front STACK

There are two stacks in this kiln.
The front stack is made up of paired, 12” x 24” shelves.
The front stack is 24” x 24”

The back stack is made up of a 15” x 24” shelf

Many of the shelves were 4” - 5”, the top and bottom have taller work from 8” - 14”. Taller work needs to be check in with ahead of time. If we only have one tall piece it may not get in.

Front Stack

Back Stack

The back stack was hotter at the bottom.
There was a hard cone 6 at the very bottom and a solid cone 6 at the top. The side port cones 6s were just starting to bend.

There was good soda distribution throughout the kiln. Work at the very bottom tended to get more… and also more heat.