Firing Schedule - Especially for Large Pots

[woodkraftbonsai]

Morning all,

I have been focusing on making larger (20"+) pots and was curious what firing schedules you all use? I'm limited by the fact that I have to fire in a studio kiln, but have some control over what the firing schedule can look like.

Any other tips and tricks for large pots would be much appreciated!

Thanks and happy potting!

-Andrew

 

[HorseloverFat]

Morning all,

I have been focusing on making larger (20"+) pots and was curious what firing schedules you all use? I'm limited by the fact that I have to fire in a studio kiln, but have some control over what the firing schedule can look like.

Any other tips and tricks for large pots would be much appreciated!

Thanks and happy potting!

-Andrew

I candle overnight at 180dF

Then on flame at 1-2 psi and 1/3 02 (basically as low as I can go).. for about 2.5-3 hours.. staying between 900-1100 dF.

Then I set the "real" line pressure, ends up being about 2/3 o2 choke open and crank it to 5 psi over about 8 minutes...

In an hour I crank to 7psi... (Over about 5 minutes)..

Then after an hour and a half I check.. if my rise is slowing... And it normally will slow in the next hour... I KNOW this, so I try to get ahead of it

So two hours after 7psi, it goes to 9psi...

Then 11... Then 14.. (there ends up needing to be some adjustment to the line pressure in between these two.. but nothing too extreme)

Then my cones start falling about 8-10 hours after I start the flame.

(That candling session and those first 2.5 - 3 hours like molasses have proved to be superbly beneficial to the structural integrity of my pieces)

 

[HorseloverFat]

Oh and with large pots, it's all (in my opinion) about how you handle the slabs... Be patient and conscious of HOW your pieces are drying.

 

[HorseloverFat]

(if the studio won't candle.. just bake them in the oven, overnight at 175dF)

 

[ABCarve]

I tend to use lower ramp speed, 200-350 f./hr. And slow it down for the last 250 f. Everything else is dependent on your glaze and what you want it to do. I put a thin layer of grog under the feet to act like ball bearings to aid with the shrinkage, which is quite a bit in large pots.

 

[HorseloverFat]

I tend to use lower ramp speed, 200-350 f./hr. And slow it down for the last 250 f. Everything else is dependent on your glaze and what you want it to do. I put a thin layer of grog under the feet to act like ball bearings to aid with the shrinkage, which is quite a bit in large pots.

I do this same thing with silica sand.

One of those simple "game-changers"

 

[woodkraftbonsai]

I'll definitely try this "game-changer". Just have to convince the studio owner

 

[mwar15]

Is it gas or electric? They probably use sand or kiln wash on their shelves.

 

[woodkraftbonsai]

Is it gas or electric? They probably use sand or kiln wash on their shelves.

He has a couple electric kilns. And he's got a couple advancer shelves, and kiln wash on the others.