Burning Saw Dust in a Wood Stove

[woodshavings]

I have just installed a Relax R2 wood stove in the workshop. No problem burning offcuts and shavings but I am wondering about fine wood dust.
I know fine dust can flare back or even explode if tipped onto a burning fire.

Any advice on how to safely burn this type of dust gratefully received!

Thanks, John

 

[mr]

In paper bags?

Cheers Mike

 

[Anonymous]

As far as I am aware, only very fine dust (such as flour) in the atmosphere will explode - can't see swdust doing that .

Bags that are tightly packed should be good as they would form a sort of fuel pellet which will burn more slowly

 

[staffie]

There have been a few threads on this topic in the past, here is a link you may find usefull.

http://www.echotech.org/technical/techn ... iquete.pdf
(This was taken from a previous thread.)

I make my sawdust in bricks and burn them that way.

Jock

 

[tim]

I don't add sawdust to mine when its going, just to start it. If you fill it and keep both vents open until the gases have ignited a burner full of sawdust can keep going all day without need of a refill.

Cheers

Tim

 

[Wanlock Dod]

Tony,

When I was at school we were shown a custard powder experiment. Briefly, a catering tin (with lid) containing a pipe (as in smoking pipe, with the mouthpiece outside and bowl inside) and a candle. Fill the pipe bowl with custard powder, light the candle, put the lid on and blow into the pipe mouthpiece. The powder is dispersed and mixed with the air, the mixture is ignited and the lid hits the ceiling as a result of the explosion. Pretty cool, although I doubt it's still performed in schools.

I've no doubt that wood dust, being a finely divided organic material, would do much the same. That said, I still smoke in my workshop (but then I doubt I would ever get enough sawdust in the air to create a potentially explosive mixture).

If I wanted to burn sawdust I'd do as Mike suggests and put it in paper bags. As it is I compost mine.

Cheers,

Dod

 

[Racers]

Hi, Tony
There had been a discuion on the Old Tools about this check out
http://people.iarc.uaf.edu/~cswingle/ar ... 81#message
Seems like care is needed.


Pete

 

[Paul.J]

I once tried mixing torn up newspapers and wood shavings for my brother in law once,as he has an open fire.
Mixed it up in a bucket,fairly dry but just enough for it to bond and put the mix into old ice cream tubs to dry out.
He said it worked fine but took so long to dry out.
Job for the summer months :wink:

 

[Shadowfax]

Tony is spot on. The dust must be entrained in the atmoshpere for explosive conditions to be right.
The custard powder experiment proves the point.
I would use the sawdust to start the fire, like Tim says, and you will be fine.

Cheers.

SF

 

[woodshavings]

Thanks for all the info...that link from Pete makes scary reading.

I do compost most of my sawdust (mix it with grass cuttings) but not those that contain any mdf or chipboard dust.

(I know, I shouldn't use mdf or chipboard !)

The suggestions of only using it initially or added in paper bags seem on the mark!!

Thanks again, John

 

[toolsntat]

We used to have one of those Tangyes cast iron burners in the workshop where I cut me teeth...
It was a cold place in the winter and we used to get it drawing that well ( mmm memories of those perfect toasted marmalade sarnies I used to have :wink: ) that the sides would glow :roll:
One day I emptied the belt sander bag onto the fire shovel (same as the railways used), flipped the front down and as I had done on previous occasions shovelled it in...
Normally this wasn`t a problem but this time I gave it that sort of a stoking the boiler action and youv`e guessed it, it went up like a goodun :shock: :shock: :shock:
The stove separated at all the joints dislodging the chimney flue , the flashback singed any stray hairs I was unfortunate to have facing it and the front of my chunky knit sweater was turned into something resembling a string vest
Nough said it was a lesson well(??) learned...
We never did that bit about fine paticle explosions at school :evil:

 

[Bean]

If you roll newspaper and fill the roll with sawdust it will burn nicely on an open fire, some of mine go that way. I also light fires with them. Some of the eco shops sell a wooden dowel to form the newspaper around and a cup to form the ends. i just twist them.

Saw dust is considered an explosive medium, but only when it is mixed freely with air, contained it will burn slowly.

 

[TNWoodwright]

Hi
Being "murican I mostly lurk. That being said you can burn sawdust safely, maybe

What I do is put a 3in tube vertically in the center of the stove. Pack sawdust around it as tight as you can. Pull the tube out and light the hole. as low as you can. I generally just throw a match in. the sawdust will burn in a circle outwardly. Mine is about 24 in round and 18in high and last about 3 hours.

I'm on the road now but if your interested I will post some pics in a week or so.

If you just want to try it out. Take a gallon can. put a tube in it and pack sawdust around it. pull the tube and light. You'll see what I mean Nice little on the job heater

Dave

 

[woodshavings]

Hi Dave,
welcome to the forum - 'muricans are most welcome - you're no longer a lurker !!
Thanks for your suggestion (and all the others), I think I've got it sorted now.
John

 

[DaveL]

I have a wood burner in the shop and all of my shavings and saw dust go into it. As shown by the exploding stove story above if you flick the fine dust in the results can be exciting. :shock:
I have fitted a long handle to my shove shovel so I can put the dust down on the fire, instead on tossing it in though the door. This works a treat.

I have been known to stack bags of shavings in the garage during the summer as fuel for the workshop in winter. :roll:

 

[Anonymous]

Tony,

When I was at school we were shown a custard powder experiment.
Dod

Yep, that's what I said, only very fine powders will explode as far as I know and wood dust is too course (I think :wink: )

I feel some experimentation coming on..........

 

[Anonymous]

Well, me and the girls have been outside burning wood, sawdust and wood shavings for the past 90 minutes and I can report the following:

a) I stink of smoke! :lol:
b) the girls stink of smoke!
c) wood offcuts burn much better and hotter than wood shavings and/or sawdust (not tried it highly compressed)
d) no matter how I threw the sawdust into the wood burner, it did not even flare up, never mind explode (pretty disappointing as the girls were excited about the possibility :lol: )


Basically, the sawdust and wood shavings from the P/T more or less smothered the raging fire and it died down quite a lot. rather than the shavings flaring up as I would expect, they sort of smoldered and burnt much more gently than the wood offcuts.

Ohh, the toasted marshmallows are very nice indeed :wink:

 

[tim]

I have found that it very much depends on what wood is used. Walnut and oak shavings don't flare up much at all but soft wood does. Maybe not very pc but MDF seems to burn the hottest.

You can certainly get a very impressive flare up if pouring on MDF dust or anything from a sander. DAMHIKT :twisted: :lol:

Cheers

Tim

 

[TNWoodwright]

Hi
Being "murican I mostly lurk. That being said you can burn sawdust safely, maybe

What I do is put a 3in tube vertically in the center of the stove. Pack sawdust around it as tight as you can. Pull the tube out and light the hole. as low as you can. I generally just throw a match in. the sawdust will burn in a circle outwardly. Mine is about 24 in round and 18in high and last about 3 hours.

I'm on the road now but if your interested I will post some pics in a week or so.

If you just want to try it out. Take a gallon can. put a tube in it and pack sawdust around it. pull the tube and light. You'll see what I mean Nice little on the job heater

Dave

Well rubbish, My apologies!! Woke up here in the middle of the night. I forgot to add that this works by drawing air up through the "tube" So if you try the bucket it has to be on some bricks with a hole in the bottom, or use this in a stove it has to draw air up through the hole you made. So there has to be a grate in the stove. My stove draws air below the fire box. Some things you don't think about when you do it every day.

Here is a link.

http://www.motherearthnews.com/Green-Ho ... Stove.aspx

Check out the images.

DOn't know why it comes up with the "report to moderator" But you can find it by googling sawdust stove and look for the mother earth news link.


And thanks for the hello!

 

[DaveL]

Hi Dave,

Welcome to the forum.

Your link has been caught by our spam trap, that will stop once you have a few more posts to your name, here it is:

http://www.motherearthnews.com/Green-Ho ... Stove.aspx