Raku Kilns

[Mark Ayers]

when I started teaching in Montana in 1975, there was a brick wood-fired raku kiln that took 8 hours per cycle. I built one using a barrel, fired with wood that could fired ...after several loads, in 3.5 minutes. It is featured in the Steven Branfman Raku Book, a Practical Approach, 2nd. ed. and it is my design. Point is, American raku is a fast firing. You can use less fuel if you insulate well and have a good efficient fuel consumption.

Marcia

 

 

 

I just found this forum and glad I did.

 

Marcia you state that your later subsequent firings only took 3.5 minutes to reach temp. Am I reading that right?

 

I take almost the same time in second,3rd,4th etc firings as I do in my first.

 

I have a 23X36 4 section ^10 two burner gas kiln. I modified the jets ( opened them up) to accommodate propane. And only run 3 rings but have ran it for a day with just 2 rings in and did not like the process so I went back to 3 rings. I have not made anything tall enough to run all 4 rings in a Raku firing and have never ran a ^10 reduction firing with it.

 

I usually take around an hour on the first firing then set my new work in the kiln and let it soak in the 600- 700 deg F kiln. After 10 minutes or so I light one of my two burners till I get to around 1000 deg F then take my time till I get to 1850-1900 then shut off the gas and pull the pieces.

 

I have played with reduction in the kiln as I am firing and know that slows things down also. I put it into reduction around 1500 deg F and hold it there until I reach my desired temp. The last few minutes I let it clear out just a bit by pulling back my baffle plate on the top. I only do this when working with a glaze that has some copper in it not in any of the crackle glaze I have used.

 

 

Prior to running my own kiln I had only been around one raku firing and so I have a lot to learn as is the case when one is new to anything.

 

I have cracked some of my work and I thought it was from to quick of a ramp up to max heat. I think the other reason is some of my work is still too think, new potter style thick.

 

I am open to anyone's thoughts on my processes and techniques in my firings.

 

 

 

Thanks everyone and again really glad I found this forum.

 

Mark

Sacramento Calif

[Marcia Selsor]

 

<br>

<br>when I started teaching in Montana in 1975, there was a brick wood-fired raku kiln that took 8 hours per cycle. I built one using a barrel, fired with wood that could fired ...after several loads, in 3.5 minutes. It is featured in the Steven Branfman Raku Book, a Practical Approach, 2nd. ed. and it is my design. Point is, American raku is a fast firing. You can use less fuel if you insulate well and have a good efficient fuel consumption.<br>

<br><br><br>I just found this forum and glad I did.<br><br>Marcia you state that your later subsequent firings only took 3.5 minutes to reach temp. Am I reading that right? <br><br>I take almost the same time in second,3rd,4th etc firings as I do in my first.<br><br>I have a 23X36 4 section ^10 two burner gas kiln. I modified the jets ( opened them up) to accommodate propane. And only run 3 rings but have ran it for a day with just 2 rings in and did not like the process so I went back to 3 rings. I have not made anything tall enough to run all 4 rings in a Raku firing and have never ran a ^10 reduction firing with it.<br><br>I usually take around an hour on the first firing then set my new work in the kiln and let it soak in the 600- 700 deg F kiln. After 10 minutes or so I light one of my two burners till I get to around 1000 deg F then take my time till I get to 1850-1900 then shut off the gas and pull the pieces.<br><br>I have played with reduction in the kiln as I am firing and know that slows things down also. I put it into reduction around 1500 deg F and hold it there until I reach my desired temp. The last few minutes I let it clear out just a bit by pulling back my baffle plate on the top. I only do this when working with a glaze that has some copper in it not in any of the crackle glaze I have used.<br><br><br>Prior to running my own kiln I had only been around one raku firing and so I have a lot to learn as is the case when one is new to anything. <br><br>I have cracked some of my work and I thought it was from to quick of a ramp up to max heat. I think the other reason is some of my work is still too think, new potter style thick. <br><br>I am open to anyone's thoughts on my processes and techniques in my firings.<br><br><br><br>Thanks everyone and again really glad I found this forum. <br><br>Mark<br>Sacramento Calif<br><br>The 3.5 minute firing was with wood.This is after a long day of firing...the later loads hit temperature with just a few pieces on wood stoked. There was a hefty bed of coals. Pots were preheated on the hot bricks of the meter long fire box. We clocked it. It was amazing. After stoking the flame would roar out of the top of the oil drum barrel which sat on top of a 20-24 inch beehive of bricks. The fire box was about a meter long and was fed by the westerly breeze. e fired lots of beginners student work. Didn't lose many pots.  I used scrap 2 x 4 from a truss factory. We split the 2 x 4s into small pieces. They burn faster and released btus faster.<br>Marcia

[Mark Ayers]

Marcia

 

That is amazing that you could get the pots to temp that quickly. I have always thought you needed to go slower even if the kiln was hot. I will try it. Usually my kiln sits at 6-700 deg F after I pull every thing out. I have pre-heated my pieces on top buy the square vent hole. However I have seen what looked like burnt glaze and thought it was because the piece was too close to the flame coming out of the kiln.

Lots to learn, and that is part of the fun

 

Mark

PS thanks for the quick reply