Stovepipe detonations tonight... scary

[NM_Shooter]

I've got a big Harman Oakwood stove.  I like the stove a lot... it has a bypass damper and burns pretty clean. 

I had a good fire going in it tonight, and I let it burn down to coals before I noticed.  I rebuilt the fire with some Juniper and Pinon, got it going pretty quickly, and dropped the bypass damper and turned down the air intake damper. 

20 minutes later, my wife came out of the back room and said "the stove is making funny noises"   

I went in, thinking it was just settling from the temperature, and watched it for a minute.  As I was watching it, I heard a "WHUMP" and a puff of smoke / ash came out of the junction between the stove and the pipe.  Holy crap. 

Doing some looking online, it appears that the stove can get into a mode where the wood outputs too much gas for the air coming in, and you can get combustion in the stove pipe itself. 

I'm more than a little spooked, as previously i have built up a big fire, loaded it with wood, closed down both dampers and have gone to bed. 

Not sure I fully know what happened, as this is the first time we have witnessed it.  I suspect it was because I had lots of coals making gas and not enough draw pulling in air.  I bet that if I don't fill it full with wood on a coal base and crank down the dampers I should be okay.  Think I'll talk with a stove shop tomorrow.

[Redoverfarm]

Frank that is not all that uncommon.  Happens mostly when the newly added wood does not ignite right away.  While left smoltering it off gasses as it smolters and then suddenly ignites.  When I add new wood to hot coals I leave the damper wide open or the door slightly adjar until it catches up.  Best time I found to add wood is when there is a flame present. You can also add a stick of kindling to the coals and then the wood on top.  Once ignition happens then I add the amount of wood that I actually need. 

Not that familar with your type of stove but they all work basicly the same in many aspects.  My parents bought a new Quadrafire and it has a feature where it opens the draft completely for 15 minutes and then automatically shuts down giving time for the wood to ignite.  Nice feature as you don't have to go back and shut the draft off manually in case you forget.

The "whump" is probably that ignition of the built up gases.  The pressure caused has to go somewhere so the joint in the pipe is the path of the least resistance if the door is closed.

[Don_P]

Couldn't have asked for woods with more volatile gasses either. I blew the door clear across the room off of one of those old oval tin stoves by loading a healthy handful of lighter knot into it. I was basically distilling turpentine inside the stove, when it finds air enough to ignite all those unburnt gases it can be impressive.

[StinkerBell]

Is this one of those stoves that have a catalytic burner in it?

[NM_Shooter]

I don't know, but I don't think so... there is a re-burn chamber, but no catalyzing compounds that I see.  It has a chamber that is lined with some sort of super insulator.  Oddly feels just like styrofoam and is just as light.  I believe that the inside of that thing gets really, really hot and burns up all the emission gasses before it enters the stove pipe.  This stove is certified for burning even on no-burn nights.

[StinkerBell]

I am no woodstove expert. Just reading this story it got me thinking that maybe this is one with a catalytic burner and that might have created the extra gas build up issue. *shrug* dunno, really. Just kinda thinking out loud. Glad you're safe and nothing burnt down.

[Don_P]

One of my bucket list things to do is to build a cupola furnace, smelt and cast iron like they did in the old days around here  . The furnaces ran an air blast driven by a waterwheel and a couple of piston pumps made like straight sided barrels which blew into a sheet metal manifold that surrounds the furnace and distributed pressurized  air to several intakes spaced around the stack. One precaution was that if the blast were shut down during fire the cover's of those tuyeres, air inlets, had to be opened to allow any gasses oxygen to be consumed quickly. If the covers were left closed carbon monoxide, yup it burns! would back up into the wind belt and when the blast was turned back on and reintroduced fresh oxygen, if a spark got swirled back into the wind belt, would explode inside and rupture that ducting.

[Redoverfarm]

I don't know, but I don't think so... there is a re-burn chamber, but no catalyzing compounds that I see.  It has a chamber that is lined with some sort of super insulator.  Oddly feels just like styrofoam and is just as light.  I believe that the inside of that thing gets really, really hot and burns up all the emission gasses before it enters the stove pipe.  This stove is certified for burning even on no-burn nights.

Frank mine has a 1" Ceramic Blanket on top maybe that is what you are seeing.

[StinkerBell]

Catalytic Combustor Process
Inside the stove lies a ceramic honeycombed shape device, called a catalyst. It is coated with a non-reactive metal, such as palladium. Most combustors are about 5 3/4 inches in diameter and 2 inches thick. When the temperature inside the firebox reaches 1,000 degrees Fahrenheit and higher, the burning wood inside the firebox emits gases. At that temperature, the bypass damper is opened so the catalyst can burn, reprocess and refine the smoke to lower the emissions exhausted by the stove through the chimney.

*this is why I was asking. I was thinking that this area just got too much built up gas and that was what you were experiencing. I would think that any extra gasses on a non catalytic would just pass through the chimeny.

[NM_Shooter]

Nope.. this one is not a catalytic burner.

This is the stove I have:  http://www.dougschimneysweep.com/pdf/harmanoakwoodwoodstovepdf.pdf

[Redoverfarm]

Not really familar with the "fire dome" technology but just reading the name it may be more prone to that sudden combustion of unburnt gases that get trapped or fail to ignite in the hidden compartments of the stove.  The best defense is to keep a flame present when loading wood.  As we are talking about stoves I have sort of let mine slip up on me.  I noticed that the door is not tightening as it once did.  Nothings changed in the hinges or latch so I guess I need a new gasket.  Just hate to let it burn out to make the repairs (gasket) this time of the year.  Maybe pick up the gasket and have it on hand for a mild day in the forecast.

Nice looking stove.

[flyingvan]

Two of my stoves have the bolt hinges machined as offsets.  Over time the doors won't quite fit like they had, so I get the big flat bladed screwdriver out and turn the hinge pins to realign the doors.  (I do it while the door is hot, since that's when a good fit matters most)  Just look to see if the hinge pins have a screwdriver slot.  If they do it's a good bet they are adjustable offsets

[Redoverfarm]

Two of my stoves have the bolt hinges machined as offsets.  Over time the doors won't quite fit like they had, so I get the big flat bladed screwdriver out and turn the hinge pins to realign the doors.  (I do it while the door is hot, since that's when a good fit matters most)  Just look to see if the hinge pins have a screwdriver slot.  If they do it's a good bet they are adjustable offsets

No mine are fixed pins in the door.  Just lift up to take the door off.  I can foresee some wear adjustment in the future. I didn't realize there were so many parts to the stove I have until I got to looking for a replacement gasket. Wow I can imagine trying to replace some of the internal ones.

http://woodheatstoves.com/download/Hearthstone%20Mansfield%208010%20exp.%20view.pdf

[StinkerBell]

Theone thing I love about this forum. The ability just to talk through situations/trouble shooting and have adult discussions.