gift
Rocket Mass Heater Manual
will be released to subscribers in: soon!
  • Post Reply Bookmark Topic Watch Topic
  • New Topic
permaculture forums growies critters building homesteading energy monies kitchen purity ungarbage community wilderness fiber arts art permaculture artisans regional education skip experiences global resources cider press projects digital market permies.com pie forums private forums all forums
this forum made possible by our volunteer staff, including ...
master stewards:
  • Carla Burke
  • Nancy Reading
  • John F Dean
  • r ranson
  • Jay Angler
  • paul wheaton
stewards:
  • Pearl Sutton
  • Leigh Tate
  • Devaka Cooray
master gardeners:
  • Christopher Weeks
  • Timothy Norton
gardeners:
  • thomas rubino
  • Matt McSpadden
  • Jeremy VanGelder

Wood stove won’t stay lit

 
Posts: 3
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Hello, so I decided to make a very large wood stove to heat my shop. The idea behind the project was to use only scrap I had laying around (don’t mind how rough it looks it will get prettied up when it’s done haha)  which led to using an old water tank which is 5’ long and 3’ In diameter. For air vents there are 2 2” pieces of pipe on either side of the door. The only chimney it has so far is a 3’ piece of 6” pipe with a dampener in it. I also welded a small piece on channel steel in the stove just below the pipe to try and retain more heat. I wanted to do a burn in it before plumbing the rest of the stove pipe and putting the stove in but I’m having a problem with keeping the stove lit with the door closed. It runs fine with the door open but dies down to only embers with the door closed and both air vents wide open than when opening the door it bellows out smoke until the fire starts up burning again 10 seconds later. Is it just not getting enough air to the back of the stove? If that’s the problem would putting another air vent into the back of the stove help?  or putting a pipe from the front of the stove to the back with air holes drilled fix the issue? Thank you in advance everyone. This is the first stove anywhere near this size I’ve made (and out of scrap)
DD204B07-F352-45B0-9C85-99C0246B3DF2.jpeg
[Thumbnail for DD204B07-F352-45B0-9C85-99C0246B3DF2.jpeg]
709528AD-8B11-425E-9314-1100D1FDF2AA.jpeg
[Thumbnail for 709528AD-8B11-425E-9314-1100D1FDF2AA.jpeg]
 
pollinator
Posts: 1782
Location: Victoria BC
317
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
I am no expert, but that is a huge stove, and yet the intakes are sized like the ones on my far smaller old Fisher, a mama bear...

The symptom sounds like lack of air.

But, since you do not have enough chimney rise to create a strong draft, it is hard to blame only the intakes.

And finally, I am pretty sure you will need a substantially larger chimney than that. 6" is only used on mediumish stoves, yours is *much* larger than anything I have seen with 6". I have no idea if you want 8, or even larger, though...
 
gardener
Posts: 1774
Location: Los Angeles, CA
562
hugelkultur forest garden books urban chicken food preservation
  • Likes 1
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
That's a good looking stove.  Obviously, you've diagnosed the problem -- there's just not enough draw.  

If you could make an adjustable vent on the front door or on the bottom of the barrel, you could slide the vent open or closed as needed, that might do the trick.

One of the issues might be the large size of the burn chamber.  Fresh air has a higher percentage of oxygen (O2), whereas spent air from the fire is full of carbon dioxide (CO2).  That extra carbon atom makes it heavier, sinking down and smothering combustion.  Your fresh air may be rising above the layer of CO2 that sinks to the bottom of the chamber -- it just floats up over the top and goes right up the chimney.  Some sort of baffle at the top of your burn chamber would force the air to mix a bit, or reconfiguring the chimney so it draws from the bottom of the back of your burn chamber rather than the top would draw air right though the burn zone rather than up over the top of the coals.

Short of that, perhaps lighting the fire right at the front of the burn chamber next to the air intake would help.  The warm CO2 would rise and go out the chimney, and hopefully not smother the fire that is being fed by the fresh O2-rich air.

Best of luck.
 
pollinator
Posts: 2339
Location: Denmark 57N
598
fungi foraging trees cooking food preservation
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator


A similar sized commercial furnace, this one is designed for straw but it will burn anything put in it. it has three air vents all bigger than yours.
 
Posts: 1510
110
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
i have one kinda like that in wood shop, mine has 2 barrels welded together end to end, you need a grate at the bottom so air can come from under what your burning, chimney has to be taller than top of building.
for a grate repurposed cast iron barbque grill grates are ideal. is that aluminum or steel you have lined the barrel with, you dont want to use aluminum inside a wood stove. if aluminum starts to melt and burn the flumes will mess you up. I had a friend die from using plasma cutter on aluminum in his shop.
 
Aidan Kelly
Posts: 3
  • Likes 2
  • Mark post as helpful
  • send pies
    Number of slices to send:
    Optional 'thank-you' note:
  • Quote
  • Report post to moderator
Thank you everyone for the reply’s. I added a grate that sits about 3” high and added another air vent made from 2x4 steel that runs under the grate until around the middle of the stove. Also made a makeshift baffle to try and force air downwards towards the fire. Last change was another air vent on the door. The stove burns good now especially when I hook a blower onto the 2x4 vent to really heat it up haha
 
Wanting to be someone else is a waste of who you are. - Kurt Cobain / tiny ad
Freaky Cheap Heat - 2 hour movie - HD streaming
https://permies.com/wiki/238453/Freaky-Cheap-Heat-hour-movie
reply
    Bookmark Topic Watch Topic
  • New Topic