Shutting down too soon?

[crater22]

Just got a new fire started in the buck, and the cat temp went to 1700 and was climbing. The temp was 450 with the IR. I had no flame, just glowing splits. Once I opened up the air again the cat temp went down and is staying at around 1400. Did I try to adjust the air control too soon. I really don't know what is too high for the cat temp to read, but it was close to the overfire mark, and I had no flames.

Thanks for the help.

 

[Woody Stover]

I have read that sustained temps over 1800 can cause the catalyst wash coat to peel off the substrate. I don't really like it to go over 1500. If anything, you probably waited too long to start cutting the air, and a lot of wood was gassing. How active the cat gets is determined by how much wood is gassing in the box. I can't remember if you bought a new or used stove; With a new stove and gaskets you should be able to slow the gassing rate down by cutting the air, but it can take a while before you will see the results, until the coals on the wood start going out and gassing rate drops. Until I replaced all the gaskets, I had to be careful not to get too much wood burning on a reload or the cat temp would go high, and with the air leaking around the gaskets, there was no way to slow the burn down, cat might go over 1800. How did you load the stove? Big coal bed? What kind of wood? Big or small splits? All these factors will affect how much wood is gassing. You can control gassing by where you supply air to the load. I will use more shotgun air, less air wash, if I want only the center of the load to catch fire on a reload, like if I have much soft Maple or other faster-gassing woods in the load. OTOH, if I have a load of Hickory, which is slower to light and doesn't gas as rapidly, I'll have the coal bed spread out more across the front rather than pushed together closer to the shotgun air. Then I'll use mainly air wash air which gets most of the front of the load flaming. Lately I've been closing the bypass around 700, keep some flame going, and temp will rise to around 1000 and the cat will start to glow. I'll turn on the blower and start cutting the air a bit, and see if the cat hangs in there strong. If the cat keeps glowing, or at least the probe temp doesn't drop really fast, I know the cat is burning. Temp may drop when I first turn the blower on, but will start to rise again if I have a strong cat burn. Stove temp will also rise. I just had an idea I might play with. If the cat temp started going high, I wonder if you cut the air wash to cut oxygen to the cat, then got a little flame going with the shotgun air, the flame would eat some smoke, and the flame and coals in front of the shotgun air would also eat up most of the oxygen. That should starve the cat, I'd think. Cat hasn't gone high since I replaced all the gaskets, though...
Yeah, you can always bail out and bypass....but it's 'inelegant,' like when a pole-vaulter lets go and flies under the bar.

 

[Woody Stover]

Dammit, I just crashed the cat on the Dutchwest, probably didn't burn in, then cut the air too much, on a couple of big splits of Hickory and White Oak on the reload. Not too elegant.