Safety Issue with Friend

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Safety Issue with Friend

Postby Oddmar » Thu Jan 16, 2014 8:00 am

I've got a problem.

My friend Glen and I built that Rocket Mass Fireplace i posted sketches of. I haven't posted pictures of it because he took most of them with his phone and posted the pics to his facebook page, and my old laptop locks up when i try to access facebook.

This is the problem. This build is smoking out the 'chimney' a bit during the day, probably because i haven't built and installed a fresh air injection plate yet. But Glen is used to box stoves, and persists in putting several large chunks of wood into the feed chamber before capping it at bedtime, so it stays hotter all night and he has a hot bed of coals to help get it going in the morning.

I went outside a week ago late at night and noticed Strong smoke smell. Using a flashlight i confirmed the 'chimney' was putting out a Lot of smoke. Inside above the fireplace you can see sticky brown rivulets of stuff that have run down the 'chimney' pipe. I told him he'd have to stop putting in wood that just smolders all night because it's going to creosote up the exhaust stack and 'bells'.

Tonight he got on the radio and asked me to go outside and make sure all the spigots were dripping, so they wouldn't freeze. My hands got pretty cold so i went into their living space and warmed my hands on the residual heat coming off the drum. I heard a popping sound and pulled off the concrete slab we use as a cap at night to find three short logs smouldering in the feed. I incredulously asked Glen if he had done this intentionally, (he forgets stuff sometimes),and he assured me it would be fine "Because the wood was fully cured".

Arrgh!

I need some feedback from people on here who know woodburners and RMH tech, because he's pretty resentful that i keep 'nagging' at him.
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Re: Safety Issue with Friend

Postby pa_friendly_guy » Thu Jan 16, 2014 4:01 pm

I can share a life experience that might help. Some years ago when I was burning the Riteway Wood stove for heat I wanted to go away for the weekend, so I filled the stoves wood box to the max [ The Box is 27" deep, one of the largest I could find at the time ] and dampened the air flow way down so it would just smolder for a long time. My thinking was that I would keep some heat in the house for a long time and my pipes would not freeze. When I returned home there was a puddle of creosote on the floor, the chimney pipe had creosote dripping from the joints, and I had a major mess to try and clean up. The floor stain never did go away. It was one of those " Learning Experiences " that we have talked about so much on here. Bottom Line, when you burn slow you build up a lot more creosote, when you burn Hot, not so much creosote. I really think it is that simple.
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Re: Safety Issue with Friend

Postby matt walker » Thu Jan 16, 2014 6:24 pm

Yep, in my opinion it's almost MORE dangerous to creosote up one of these things. In most of 'em, if you really are using seasoned wood, I think it's practically impossible to build up any because truly there should be no way of slowing it down. It should burn flat out, all the time, period. That's of course a bit theoretical, there's always going to be conditions where even the best RMH is going to have some wet wood, or a cap put over a bit of fuel, but typically the caps have air inlets so they can't really be shut down. Of course, you want to shut it down when it's out, so there is an advantage to building a means to completely close it off, but with that comes responsibility. I know you know all this Oddmar, I'm just putting it here for folks who might be new to all this.

I think his situation is particularly dangerous because these heaters are supposed to burn full out, essentially having a controlled chimney fire in the riser every burn. You might explain to him that while a box stove is never supposed to be "overfired", a RMH is, and therefore he's got a perfect storm coming. A build up of flammable stuff in there, and a fairly consistent ignition source in the form of 1000°F hot blast heading up into the place where the most creosote will collect, the first radiator. If he does fill that up and get it to ignite it could burn it's way all the way through the system. I shiver at that thought. Maybe sneak in a little extra air somewhere and make it so it can't be closed off? I dunno man, that's tough.
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Re: Safety Issue with Friend

Postby mannytheseacow » Thu Jan 16, 2014 7:24 pm

I wonder if this is an issue of type of wood? A while back I posted that photo of how my chimney plugged up- well, 3 weeks later it happened again. 3 WEEKS! I burn as hot as I can, and don't try to keep anything smoldering slowly. We confirmed my wood supply was plenty dry. I don't know enough about what those residues are but theses are things that have crossed my mind.

Likewise, I have had creasote dripping from the stove pipe where the bench converts to the cement chimney space. I don't have any significant build-up in the bench. I haven't popped the barrel off but from what I can see from the plenum clean-out there is no buildup there, either.

Either way, I think Guy and Matt are both right, I wouldn't be encouraging any choke-back on the system, but it also appears that there's a mystery to solve, gang!
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Re: Safety Issue with Friend

Postby matt walker » Thu Jan 16, 2014 7:39 pm

Manny, I'm pretty sure you have a condensate issue from such low chimney temps. You've got a reflux still going there, that's my guess. You and your big ol' bench.
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