Cordierite didn't Last Trying Corelite now?

[ozzie88]

Well got threw one winter with homemade boiler had good luck just the one panel I use to seperate the two chambers did not hold up,cracked? was 5/8thick. rated 2400* I talked with company said shock from starting up did it.They get red hot bright. So I got 1inch honey-cone Corelite they said be better? So far so good. I am so glad I built this with changing these panels in mind so not to hard to do. If this done work next is Silicon-carbide I think??? Any ideas????
Still fireing boiler every 30to40hours now since Sept. used 3 1/2 cords have small house.
1st photo is chamber 2nd fireing ,next is bottom of panel first chamber,pipe injects air to top of bottom chamber

[updraft boiler]

 

[hobbyheater]

View attachment 65359 Well got threw one winter with homemade boiler had good luck just the one panel I use to seperate the two chambers did not hold up,cracked? was 5/8thick. rated 2400* I talked with company said shock from starting up did it.They get red hot bright. If this done work next is Silicon-carbide I think??? Any ideas??

Anything that is only 5/8" thick will have difficulty standing up.
Red hot is not very hot if you look at this graph for ceramic temperatures by color. http://www.ceramicartdaily.net/PMI/KilnFiringChart.pdf
Rapid expansion and contraction can really raise hell with reinforced refractory.
Pictured below are two tunnels from a Jetstream boiler. You can see the end of the old tunnel has broken off. This extended portion always breaks off first as it heats faster than the rest, causing a stress crack and the break. Does your partition fail from the center out?
Pictured is the refractory base for the Jetstream to give you an idea of the thickness of the walls and partition between chambers.
Pictured is the stainless steel refractory needles used to hold the refractory together should cracks develop.

 

[slowzuki]

I've always wondered, given the different expansion rates of ceramic and steel, the needles must also generate cracks in the refractory too while holding them together after they crack?

 

[ozzie88]

That chart and info you gave me was very helpfull! Thanks alot, I did make room for thicker panels when this one gives out will go to 1inch and see?