Cords of Sawdust in Firewood Pile

I was curious as to how much sawdust is in a pile of firewood. Loving math, and making some assumptions I came up with the answer:

For every 26 cord of tree length firewood, 1 cord of sawdust will be produced.

That is assuming the trees are around 12 inches in diameter on the butt then taper to 2 inches 50 feet down the tree, with two 15 foot limbs also cut into firewood. This also assumes 7 trees to make a cord of tree length wood, and the saw would be using a 3/8 chain.

Anyone else do the math and figure out how many cords of sawdust are in a firewood pile? I am just curious as to how close I was in comparison to their figures.

 

Hmmmm Wondering if I should stack the entire cord of sawdust, or let it season as it lies. Decisions decision.

 

I got a pot bellied stove so my method of logging is to back my log trailer next to the tree, fell it, then using the grapple to hover the log over my dump body, cut the tree into stove lengths; kind of a one touch firewood process stump to firewood shed.

Well we have a pet rabbit here so she uses some sawdust as bedding, well cutting all my wood over the dump body, it catches all my sawdust too. Even after dumping the load I got a 5 gallon bucket of pure sawdust that remained behind, and put in the bunny hutch; that was what got me to bring the calculator out. Just how much sawdust is there in a pile of firewood I wondered? I knew it was quite a bit.

 

I think you hit the nail on the head! There are soooooo many variables. I think there might be a plus or minus of a lot, by way of percentage. Sharpness, type and angle of chain, softer/harder wood, kerf of your bar and chain just to name a few off of the top of my head.

My step father and did the same for me when I was young. He had me clean up all the dust and noodles for the rabbits. It worked great and it seemed there was always just enough! lol

I'm very curious if anyone else can weigh in and give another estimate for you.

 

I actually did similar a few years ago while cutting up the last log load.
Wasn't trying to calculate sawdust, but trying to figure out how much of the logs was lost to the chain kerf. It was eye opening, but I don't remember the numbers.
Must be a little OCD, but I like keeping track of stuff............to a point.

 

and point is when you need to remember it..

just teasing Dave struck me as funny you would figure that out and then not umm write it down

 

I could recalculate, but I don't wanna. Ok, I did a rough calc. Lost about 2' in approximately 20 small 8' logs. 1/4"-ish kerf.
No idea how much sawdust that is.

 

I think your calculation might be pretty close. Years ago I posted here a pic (too long ago, can't retrieve it now) of my Ford Ranger bed totally filled with chainsaw chips from processing 5 cords of wood. The Ranger bed measures out to about 1/5 cord.

 

I know by the time I'm done cutting up my tandem load of oak I'll have made about four trips with the snow bucket on the tractor to the sawdust disposal pile. I think it's a six foot wide bucket.
I'm always surprised at how much there really is.

 

Diameter of the log shouldn't be a factor. If you look at the face of a stack, every piece got cut and some came out as waste. Whether the round began as a 2", 10" or 40" diameter, once split there is no difference, its just wood in a stack. However the length that you cut it makes a big difference. In a 4x4x8 pile and cut to 16" there would be three slices of waste compared to two if you cut to 24".

And if you noodle your waste factor goes up very fast.

 

You are right, a person would have the same amount of sawdust if they cut up nothing but 2 inch saplings to produce their cord of firewood versus 12 inch logs; they would just do so from a lot more cuts.

I did it the other way, figuring out the volume of chips produced per cut, then figured out how many cuts per tree, then knowing it takes 7 trees roughly a foot in diameter to make a cord; calculated it that way. I did fail to mention I calculated a 16 inch length. I think it is a better way to do the calculation though because there is no need to adjust for the air gaps in a cord of wood.

If you assume a cord of wood has (2) cuts, 48 inches deep and 96 inches long, at .375 for a kerf, it makes the assumption that there is no air gaps, and we know that is not truly accurate in a pile of wood. If we could all agree on what the percentage was for that air gap, that would be an excellent way to calculate how many cords of wood it would take to produce a cord of sawdust chips.

One thing I did not calculate though was sawdust chip swell. This is no different then mining gravel. In that case ripping into the earths crust makes it less dense and so it has "bucket swell" around 25%. I have no idea what the swell would be in a wood chip. It really should be calculated in.

 

My brain hurts.

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Probably a fairly close assumption of the amount of waste, judging from what I have hauled away after the clean up form a truck load of logs delivery....

Ever consider a career in the logging industry??

 

As always Eric VW you come up with another great idea!

Please allow me to expand on it just a bit further.

Instead of compressing the sawdust into log shaped lengths, one could compress it into smaller oval sized pellets and package them into bags for easy handling/storing.

In addition, one could also offer a specialized stove in which to burn said pellets. The variety of these said pellet stoves would be endless......

The sawdust from which the pellets were made, albeit softwood or hardwood, can be brought into play on just how much to charge for this type of waste fuel.


Aw, forget it! It would never catch on. Who in their right mind would ever prefer something like that to burning real wood???

 

After sawing, I get out my leaf blower and blow the chips into a pile, which is then scooped up, mixed with fresh grass trimmings and tossed into the compost bin.

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I've been going over the sawdust on the grass with the lawnmower. It seems to pick up most of it, as long as I do it pretty soon after sawing.

 

That is perfect; adds a lot of nitrogen to the pile and gets it really cooking.