Scaling logs

[Maverick]

Hi guys, great forum.

      I'm new here so I hope I'm posting this in the right place. Can anyone tell me how to convert cubic feet of wood to cords. I know the volume of a cord is 128 cubic feet but is there a conversion formula from cubic feet of wood to cords. All my logs are measured, dia. and length and I used one of the many wood calculators to get the cubic volumes but it just seems to me that it takes more than a cord of logs to make 128 cubic feet of wood. Normaly I wouldn't worry about it but the man I'm buying these logs from wants to be paid buy the cord and I don't want cheat him.
thanks 

[scsmith42]

Mav, according to my Pocket Reference, to convert from cubic feet to cords multiply the cubic feet of wood times .00781.

Scott

[Maverick]

Thank you Scott, that may be right but it's the same as dividing it by 128 and like I say that may be right but it seems it takes more than cord of stacked logs to make 128 cubes of wood.
Maverick

[scsmith42]

Maverick, I wonder if the difference would be in the amount of waste between cordage and board footage?  I've always heard that cordage included all of the wood - including the bark.  However board footage is measured based upon cuttable lumber from the small end. 

Therfore, it would indeed requuire more than a cord of stacked logs to make 128 board feet of lumber.

[Tom]

Maverik, it does.

A cord of wood isn't solid wood.  It is a 4' x 4' x 8' of round or split wood that is stacked as reasonably tight as can be.  The volume of the stack is 128' but the volume of wood in the stack may not be 128'.   It means that there is air in the stack.

Board footage and cubic feet are ways of measuring a volume of wood with no allowance for air, though some allowance may be made for kerf, slab or taper in scales used to determine the lumber contained in logs.

Here is a quote from a Missouri site, but most states follow this rule/law.

As defined by the National Conference on Weights and Measures and Missouri rules and regulations, a gross cord of firewood is the amount of wood, ranked and well stowed, contained in a space of 128 cubic feet.

You will find that Cords are also represented by weight.  Depending on the mill, the species of wood, the time of year, etc., A cord of wood is considered to be about 5200 pounds, but, it may run as high as 5600 pounds.  Variances outside of these numbers is even possible.

Weight is usually used for tree length logs sold by the truckload at a mill.

[Maverick]

Thank you Tom, that definitly makes sense and thats probably why not to many people buy and sell in cords anymore, two many variables. I was once told by old timer in the buisness that they used to count on using 2 cords of wood to cut a 1000 ft. You think I could reverse engineer a number from that some how.
Maverick 

[Tom]

The amount of footage you can cut from a load of logs or number of cords will vary depending on the quality and size of the logs.    Naturally.....duh!  :D

I have only measured one load of logs and equated it to the footage that I sawed with my bandmill.  I sawed 3800 Board Feet of lumber from 9.3 cords of cypress.   These were tree length and the tops were waste.  They were also not very large logs and, as I remember, were about 14 or 16 inch butt logs and were snakey. (crooked).  the rest of the logs in the tree held at 10 or 12 inches untill reaching the tops where they dropped to 6 and 8 for a long distance.

Check out this LINK

[johnjbc]

This link has conversion facts that should answer your questions
http://forestry.about.com/library/blwoodconvert.htm

[RSteiner]

In several older publications I have read the soild wood volume in a cord of wood is figured at around 70 cubic feet.  This allows for the space between pieces.  I do think this allowance was figured for a cord of round wood, unsplit, where the pieces were cut 4 feet long, straight, and an average diameter for pulp wood at the time.

I think the volume of solid wood in a cord of split wood today maybe close to this or a little less depending on how tightly the pieces are stacked. 

Randy

[Woodhog]

I was once told by old timer in the buisness that they used to count on using 2 cords of wood to cut a 1000 ft. You think I could reverse engineer a number from that some how.

Your above statement is what we use around here for equating cords to board feet..for spruce the mill gives a weight of 10300 pounds for the logs to saw out 1000 feet of lumber. They use band saws and the scale is New Brunswick log scale a log 12" x 16 feet equals 96 board feet, they say one board foot of spruce weighs 10.33 pounds...so if you know the weight of your cord of wood you can work it out!!!  ( I think).. :D

[extrapolate85]

In general, a cord will range from 50 - 70% solid wood (so 64 -90 cubic feet of solid wood). This ratio will vary depending on: the quality of the stacking, presence of knots, butt-flare, bark thickness, diameter of logs (small logs having more bark and void space than large logs) and length of logs (in general longer logs increase void space). The most often used conversion is that a cord has 66.67% solid wood (85 cubic feet), 11.46% bark (15 cubic feet), and 21.87% void (28 cubic feet).