Anyone had this happen?

[DaHole]

Setting the stage:

After an overnight burn of 7 hours I was left with just a small bed of coals in the morning. I stacked four small splits around, it dropped a handfull or two of wood sweepings (I don't throw the floor mess away I put it in a pail and use it) and then put a couple more splits accross the top. In about two minutes I had a nice little fire and my stack temp was up at 500 already so I put in a nice size split, and dialed the air back as low as it would go. For about 3 minutes I had an incredible reburn comming out the airflow of the roof and then it setteled down to a nice hot glow of red with no flame.

This is where it gets interesting:

I am sitting in my chair right in front of it working on my laptop and can see in the stove over the top of the screen (Thats what I call working from home) Anyway the nice red glow has been going on for about 10 minutes when the stove FLASHED. I have seen a fire flash before but never inside of a stove and it flashed so hard that I heard a little bit of air get pushed out through the door with a short squeak, and it was then confirmed with that lovely telltale aroma of a wood fire. It was very cool, the entire inside of the stove was on fire, but only for about a half a second and then it settled back into just a small flame here and there.

 

[Fsappo]

Just the wood releasing gasses faster than they can burn, for lack of a better description. It can happen when adding dry wood to a hot fire and closing down the air. The gasses build up and flash. It shouldnt be a common thing to have happen. Just sit back and enjoy the smell.

 

[Slow1]

You had smoke/flammable gases build up in the firebox mixed with air but without a source of ignition for a while. Finally the mixture was just right for the temperature (temperature may have gone up or enough oxygen got into the mix) and it flashed. Think of what happens inside a diesel engine (no spark plug there - pressure is what finally pushes temperature up high enough to cause ignition). In any case this situation can actually get VERY dramatic - folk have reported loud noises and quite a bit of smoke in the room. Stoves with lids that just sit on top have been known to pop up (ever wonder why there are screws in the stove pipe?). Although it may have been nice to look at you really don't want to have explosions going on in your stove very often.

IF this happens on a regular basis then to avoid it give a bit more air - keep a flame in the stove. If you have trouble doing this then consider your draft situation - you may have marginal draft or other such issues.

 

[begreen]

It sounds like the air was cut back too soon allowing the fire to die out and the fresh wood to smolder and wood gases to accumulate. When a flame appeared, the gases ignited into what is called a flashback or puffback. Try to avoid this by cutting back the air at first until just when the flames get lazy, but are not snuffed out. Hold off on closing the air off all the way until the wood is nicely charred.

 

[soupy1957]

either that, or your dog got too close to the stove, and farted!!

-Soupy1957

 

[n3pro]

either that, or your dog got too close to the stove, and farted!!

-Soupy1957

That's what I tell the wife all the time it was the dog :red:

Back to the topic - don't close the air down so far so quick. Do it in stages.

 

[Backwoods Savage]

Setting the stage:

After an overnight burn of 7 hours I was left with just a small bed of coals in the morning. I stacked four small splits around, it dropped a handfull or two of wood sweepings (I don't throw the floor mess away I put it in a pail and use it) and then put a couple more splits accross the top. In about two minutes I had a nice little fire and my stack temp was up at 500 already so I put in a nice size split, and dialed the air back as low as it would go. For about 3 minutes I had an incredible reburn comming out the airflow of the roof and then it setteled down to a nice hot glow of red with no flame.

This is where it gets interesting:

I am sitting in my chair right in front of it working on my laptop and can see in the stove over the top of the screen (Thats what I call working from home) Anyway the nice red glow has been going on for about 10 minutes when the stove FLASHED. I have seen a fire flash before but never inside of a stove and it flashed so hard that I heard a little bit of air get pushed out through the door with a short squeak, and it was then confirmed with that lovely telltale aroma of a wood fire. It was very cool, the entire inside of the stove was on fire, but only for about a half a second and then it settled back into just a small flame here and there.

I agree with the others. Backpuffing is a common problem and as Slow1 mentioned, it can get violent. Sort of reminds people to make sure their stove pipe is screwed together. Backpuffing also gets that smoke in the house and at times it can be a lot. I remember one stove we had that was a bit difficult to control at times and we had quite a bit of backpuff with that and the chimney setup we had at the time. We fixed that fast.

Another cause of backpuff is wood that is not dry enough. With this you naturally get more smoke. Then with the draft cut low (as you did), the smoke sort of hangs up in the stove and chimney. Suddenly the flash of backpuff and that sends the smoke out and gets you a draft again. So naturally one needs to look at the chimney. Sometimes people need to add more chimney.

Of course what you did, you had a hot fire going with 4 splits....then you added 2 more. So 6 splits plus the other stuff and that is a pretty darned good fire for this time of the year. The mistake, of course, was to add the extra wood and then dial the draft down. Had you just turned the draft down without adding the new wood, you would have been fine.

So, always remember, whenever you add wood to a fire, you need to burn it hot right away, at least long enough to char the wood. Then turn the draft down.

Good luck.