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Can I burn Sawdust, Woodchips or Hardwood Mulch?

Post in 'The Wood Shed' started by GKG-MO, Feb 20, 2009.

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  1. GKG-MO

    GKG-MO New Member

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    I hope this is the right place to ask this. I have a traditional wood/coal boiler with shaker grates and forced draft. I mentioned to a coworker that I burn coal sometimes to augment my wood supply and increase the burn time. He suggested burning sawdust or woodchips. I can get either of these free or at little cost. My questions are will they burn up quickly or smolder for a long time? Will they make any usable heat? Will this cause a lot of creosote? My coworker claims he burns hardwood mulch in his wood furnace with no problems but I have known this coworker to lets say stretch the truth a bit.
    He also claims that he puts sawdust in a five gallon bucket with small holes in the bottom and wets it down. Then he puts another five gallon bucket on top and fills it with stone creating a sort of press. He claims after a couple weeks he can pop the saw dust out and it holds together making what I guess you would call a poor mans bio brick. Is this possible?
    I can almost believe that the hardwood mulch would burn OK because of the grates and the air moving through but I would think it would burn up quickly. He claims they don't. I'm going to try it next year just to see but i wanted to get the thoughts of the experts.

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  2. Adios Pantalones

    Adios Pantalones Minister of Fire

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    As I understand it, a coal burner arrangement may be better for these sorts of fuel charges as the air enters under the fuel. You really have to watch out for moisture, and getting mulch and wood chips dry may be a lot more effort than it's worth unless you have a clever system.

    As for the bucket, etc- really, is that worth the effort? A couple of weeks? Just compost it, IMO. It won't be that dense, so really you've put in all that work to effectively get one or 2 sticks of wood worth of heat. 5 minutes cutting outside will get you 10 times that at least.
  3. Dune

    Dune Minister of Fire

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    No doubt a coal stove will burn wood chips, but as far as long burn times, I don't think so. The moisture content is not really an issue though, you will just burn more chips for the same heat if they are wet. Either way, plan on shoveling in chips on a regular basis. Why don't you try it and let us know what you find out?
  4. GKG-MO

    GKG-MO New Member

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    I'm not in a big hurry to try it as coal prices have tanked and its cheap, convenient and extends the burn time. I do plan on trying the mulch but I was afraid it might burn up pretty fast. Has anyone ever tried burning it?
    The bucket trick does seem like a lot of messing around when I think about it. Do you guys even think it would work?
    I wonder if you could use "3 pvc pipe strapped together in a block and make a lot of these "poor mans bio bricks" at once? Its still a lot of effort for the payoff but for those that buy wood it may be worth it. Really most of the time is drying time, not that much work involved.
  5. TreePapa

    TreePapa Minister of Fire

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  6. Backwoods Savage

    Backwoods Savage Minister of Fire

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    Sawdust: it depends upon where it came from. From a sawmill? If so, the logs were probably pretty green when sawed. It takes a long, long time for sawdust to dry out enough to burn. That stuff will just smoke and smoke, and smoke, etc. Not worth the bother.

    Mulch? Has it been treated? If so, stay away from it.

    Some people just seem to have to try odd things. Better to stick with proven wood or coal.
  7. crazy_dan

    crazy_dan New Member

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    sawdust is good for the electric meat smokers as it likes to smolder and not really burn much.
    you could burn any of these things as long as they were not treated with anything.
  8. GKG-MO

    GKG-MO New Member

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    The sawdust is from a pallet shop close by so I think it would be dry, but the more I think about it the mulch would probably be the better way to go. Around here the Amish sell hardwood mulch that is pretty much just copped up hardwood. I think I'll get a load next year and try it just for fun but I was more curios than anything. Coal is so cheap right now why bother with either. That could change in the future though. It would be nice to have an alternative.
  9. Wet1

    Wet1 Minister of Fire

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    OT.... what are they getting now per ton?
  10. GKG-MO

    GKG-MO New Member

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    Last load I got was $85 a ton but I get medium grade coal. Run of the mine is about $70. I mix it with wood so a half a ton lasts me three weeks to a month and I get 12 hour burn times :).
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