Lets Speculate. What could have caused this explosion?

[Guest TankerHC]

I am not making light of this. Serious question. We have been loking at these Chimneys, went to a friends Anniversery Party last year. He has one of the larger ones from Lowes I think. Standing around talking about how nice it was having a fire without having to worry about it spreading around the area, he mentioned that "he heard" you have to keep a close eye on these things, use them wrong and they can become super heated and explode. Im thinking really? BS. Read half a dozen articles on this seeing if anyone finally figured out what caused the explosion. Not even the fire department has figured it out yet. Exploded, killed a guy and blew holes through the door of a car parked in the street. Think they threw something in or is it really possible that this thing got super heated and exploded? No one at the gathering seems to know what happened, they were all just sitting around and BOOM! (?) Sounds kinda strange. http://www.firefightingnews.com/article-us.cfm?articleID=105150

[c.a.willard]

Can you show a picture of one, so we better know what your talking about.  In my mind i'm seeing an out door fireplace, which assuming its maintained shouldn't be a problem.

 

I wonder if something weird is going on inside the system and acting like a gasification unit trapping the wood gasses and then allowing them to be ignited.  Either that or there is trapped air somewhere in the system

[Guest TankerHC]

Along these lines. Our friends in MS have something like this only not as elaborate. Generally the same shape. And I dont think there's is aluminam, think its some sort of ceramic. 

 

http://www.thebluerooster.com/catalog/chiminea-p-81.html?gclid=CNaqzqK61bkCFatj7AodmwcAaA

Edited September 18, 2013 by TankerHC

[billyscott]

I had one made out of clay. Lots of fun. Finally it cracked from heating and cooling so many times.

I can't see how one could explode like the article describes. I'd have to guess somebody tossed something in it.

[monkeylizard]

You can get propane fueled chimineas. Maybe that's what they had.

[Guest Keal G Seo]

I would say 1 of 2 things. Either someone threw something closed into it, that when it exploded flew far enough away from the scene that it wasn't recovered. Or, someone spilled something on the outside of it after it was heated. The sudden cooling could have cause multiple fractures fast enough to send shrapnel flying. But since they said it sounded like artillery I am guessing the former.

I think if they had had a propane one it would have just been ruled a gas leak.

[Guest Lester Weevils]

I have an iron one bought from home depot, which has held up weLL. They also at least sometimes sell the ceramic ones.

My iron model has a a spark screen that sets in the top, and a lid that looks like an iron pot lid, to keep rain out of it day to day.

Maybe if somebody put the lid on when wood is still smoldering, it could collect enough wood gas in the chimney to go "chuff" and shoot the lid up in the air? Doesn't seem big enough or sealed enough to do much. Maybe the lid would stay put and it would just barf cinder sparks out the bigger main opening in the bottom?

The ceramic ones, dunno if they come with spark screens or lids.

[Dustbuster]

If the car in the driveway had a tire flattened,and holes in it, along with the extra collateral damage,i promise it wasn't from air trapped in that cast chimnea. if a kid threw in a flashlight or something with lipo or li ion batteries i would accept that because ive seen those go off. scary to say the least,but it took a lot of power to damage the car at a distance, we may have a sapper or IED SME on here that may elaborate on this but something " aint kosher"...............

[Guest Lester Weevils]

OK, speculating-- Wonder if they were using one of those packaged fake logs made out of sawdust and chemicals?

The ones I've used seem to have some kind of tarry stuff in em. Wonder if those products ever have a little bit of nitrates in the mix as accelerant to make sure the fake logs burn completely?

If so, maybe a real bad quality control error could produce a mutant log with LOTS of pottassium nitrate or other oxidizer mixed with the tar and sawdust? Edited September 18, 2013 by Lester Weevils

[Smith]

OK, speculating-- Wonder if they were using one of those packaged fake logs made out of sawdust and chemicals?

The ones I've used seem to have some kind of tarry stuff in em. Wonder if those products ever have a little bit of nitrates in the mix as accelerant to make sure the fake logs burn completely?

If so, maybe a real bad quality control error could produce a mutant log with LOTS of pottassium nitrate or other oxidizer mixed with the tar and sawdust?

I could see that but you would still have to have something over-pressurized inside the pot to explode with that kind of force. IMO

 

I'm leaning towards some flammable container getting thrown in. When there is a fire there is always someone who wants to see what will happen to random things if they throw them in the fire.

[Guest Lester Weevils]

I could see that but you would still have to have something over-pressurized inside the pot to explode with that kind of force. IMO

I'm leaning towards some flammable container getting thrown in. When there is a fire there is always someone who wants to see what will happen to random things if they throw them in the fire.

Yes those are good points. My wild speculation assumes several things. Use of a sawdust log, trace amounts of oxidizer part of the intended formula, etc. OTOH I read that some cigarettes contain added oxiders to make em burn smoother, so it wouldn't be unknown to do something like that.

Was just thinking, a big chunk of potassium nitrate that was sposed to be diluted in 100 gallons of liquid falling into the log mold, along with sawdust and some kind of tarry aromatic stuff. Might make a genuine explosive like diesel fuel and fertilizer, dynamite or gunpowder? Something that would go boom even if it isn't tightly enclosed in the firepit?

[peejman]

Low quality aluminum castings can have a significant amount of entrained hydrogen gas in the form of porosity.  Heat cycles will cause the aluminum to crack, and very high heat could melt the aluminum and release the hydrogen.  It only takes a little hydrogen to make a big boom. 

 

Do I think that's really possible?  No.  I think someone put something in the fire. 

[Guest TankerHC]

Readint the Fayette Observer, the Fire Department said they couldnt check the Chimnea because it completely exploded and was gone. Said there could have been a propane tank nearby, but if so, thats gone too. Must have been one heck of an explosion.

 

Checking Chimnea websites and one Handyman website, they all say the same thing. DO NOT USE ANY TYPE OF ACCELERANT! Chimnea's, being enclosed will explode like a bomb if you use an accelerant. 

 

FD hasnt questioned the witnesses yet, but one guy who was there said they were standing around and he heard two explosions. First a small one, then the whole thing exploded. 

[Smith]

Readint the Fayette Observer, the Fire Department said they couldnt check the Chimnea because it completely exploded and was gone. Said there could have been a propane tank nearby, but if so, thats gone too. Must have been one heck of an explosion.

 

Checking Chimnea websites and one Handyman website, they all say the same thing. DO NOT USE ANY TYPE OF ACCELERANT! Chimnea's, being enclosed will explode like a bomb if you use an accelerant. 

 

FD hasnt questioned the witnesses yet, but one guy who was there said they were standing around and he heard two explosions. First a small one, then the whole thing exploded. 

That would make a little more sense. If there were a leak in the nearby propane tank and the small "pop" was the ignition of the leak and the larger explosion was the propane tank itself, that would explain everything.