Calculating cords per log

frazman · February 02, 2020, 08:39:27 PM

I have an opportunity to buy some spruce logs for milling but the prices is per cord and I would like to know how many logs would equal 1 cord before ordering.
I know all the logs are not the same size and from what I found on line, 500 bf = 1 cord but is there a site that would give me what a size of log = cords meaning 1 log ( small end dia x length ) would give me part of cord. Figured I'd ask. Thanks.

WV Sawmiller · February 02, 2020, 09:12:12 PM

Here is what I found asking that question on line:

According to Google 1 cubic foot equals 12 board feet, so it will take 1536 board feet to make a cord. That is about 7 logs 18 inches on the small end and 16 feet long.

That confuses me as I thought a cord was 128 cubic ft (a stack of firewood 4'X 4' X 8'_If that was the case you'd think a cord would be 128 bf. Are there different cords?

luap · February 02, 2020, 09:30:58 PM

Logs will have more air space so yes the actual volume of wood per cord will be a lesser fraction of the 128 cubic ft. In my experience it comes down to what the trucker says he can haul per load and he is not hauling anything less than a full load. Maybe you plan to haul your own - you didn't say. Look in the toolbox on the left side of the page. You will find some useful information there that will help you for what you are asking.

dgdrls · February 02, 2020, 09:49:41 PM

Meauring cords of wood in a log? in Forestry and Logging

Looks like 80/90 Cu.Ft of logs for a cord,

Tables here as well https://www.fs.fed.us/ne/newtown_square/publications/research_papers/pdfs/scanned/OCR/ne_rp338.pdf

D

GeneWengert-WoodDoc · February 03, 2020, 01:28:40 PM

As a rough rule of thumb, each cord of logs sawn into lumber has 500 bf of sawn lumber. The logs' diameter and straightness affect the actual answer, as well as bark on or off. This is for eight foot long logs.

Although a cord has 128 cubic feet of logs and air, there is roughly 85 cubic feet of wood, again depending on straightness and bark. When sawing, we might see around 40% to 60% of the volume of a log converted to lumber, varying with diameter.

There are different sizes for cords...for example, a "face cord" is 4'x8'x 16" or other piece length, such as 24" instead of 16". There are regional differences in the cord size and volume too. So, one might use the term "standard cord" for the 4'x4'x8'. Note that the amount of wood is more when using 4' lengths. Also, the amount of wood will be reduced as it dries by about 10%, so a full cord green that dries will not be 4'x4'x8', but will be about 4'x3'7x8' and will have maybe 77 cubic feet of wood. Is it still a cord, or do you have to add 10% more wood to get the dry cord up to the full size?

moodnacreek · February 03, 2020, 06:34:29 PM

I always heard 2 cord to the thousand board foot log scale. Don't ask me which log scale. North eastern cedar mills would really know how this works as they take truck loads of small straight n. white cedar logs and saw or turn them. They , to the best of my knowledge buy by the cord. This would not be doyle for sure.

frazman · February 03, 2020, 11:15:01 PM

I had the opportunity to go see the trees and talk to the owner today. He's a farmer looking at clearing some bush and will be clearing land for the next few years. The logs will be deliver in his grain truck. I'll see how things turn out and may even order some ash next year. Thanks for all the help and info.

barbender · February 03, 2020, 11:32:28 PM

I've always used the 500 bf per cord rule of thumb, typically I get better recovery than that but it's a good guide. Another way to look at it, if you had 8' logs that were perfect 12" cylinders, no taper end to end, you would have 16 of them in a cord. 4 rows of 4. If he is dumping them with a grain truck, you're not going to be able to measure cords. You need it stacked for that. You can scale them to board feet, and then convert that back to cords using the 500 bf figure. International seems to be a pretty fair scale for buyer and seller (I admittedly don't have a lot of experience with these methods- I'm basically explaining what I would do in the same situation). You can find the tables online for the scales.

TKehl · February 04, 2020, 07:12:30 AM

FWIW, when I sold the the local cedar (ERC) shaving mills, they would measure the width and length of the pile on the trailer, then take a few height measurments for an average to calculate cubic feet. Then use this to figure how many cords was on the load.

Of course, this was 4' bolts limbed tight and stacked straight. YMMV. There's a good chance they will be somewhat jumbled just on the grain truck before he dumps. ;) :D

frazman · February 04, 2020, 09:51:56 AM

When I spoke to the owner we had a good conversation and I did mentioned the concern on how the logs would be place in the box. He totally understood my concern and was going to do his best to give me the cord amount I would order. Once it's all said and done and the logs are unloaded, I'll calculated the bf from the logs I have for future orders.

If I have paid a little more or the cord amount is a little less, I won't mind as others I have contacted will not deliver anything less then a full trailer load and this is just a hobby and not a business. I'm not looking at selling milled lumber. Looking forward in using my mill.

luap · February 04, 2020, 11:08:51 AM

It sounds like he is trying to give you a fair deal and gives both you and him some flexibility. If you are satisfied, then go for it. Once those logs are unloaded they won't measure out the same on the ground as they have been jumbled and rearranged. More than likely when all is said and done you are going to be saying "I wish I had gotten more of those." Now might be the time to get a scale stick, learn to read it, and actually measure the board ft of some of the logs and compare to how they saw out.

barbender · February 04, 2020, 12:56:16 PM

The main thing, no matter what scale you use, is that the buyer and seller are both satisfied with it.

moodnacreek · February 04, 2020, 01:36:00 PM

Quote from: luap on February 04, 2020, 11:08:51 AM
It sounds like he is trying to give you a fair deal and gives both you and him some flexibility. If you are satisfied, then go for it. Once those logs are unloaded they won't measure out the same on the ground as they have been jumbled and rearranged. More than likely when all is said and done you are going to be saying "I wish I had gotten more of those." Now might be the time to get a scale stick, learn to read it, and actually measure the board ft of some of the logs and compare to how they saw out.

This is the best way to learn. Get the stick that is most used in your area. Scaling and sawing and scaling the lumber will teach how to estimate deductions for log defects. On really nice logs try to beat the scale.

frazman · February 05, 2020, 02:50:10 AM

I know I have lots to learn but I'm not sure what a scale stick is ?

For sure I will order x amount of logs and as mentioned when they are delivered and sawn I will wish I had ordered more with new projects in mind. There will always be next year.

I have taken down a good number of white poplar logs to practice on before I get into the good.

moodnacreek · February 05, 2020, 08:06:56 AM

It is a chart impressed on a wood 'yardstick'. You measure the small end of straight log inside bark, go to length and read the bd. ft. it contains. Of coarse there is more to scaling than this simple method but if the man that scales , saws, he will become a scaler.

frazman · February 05, 2020, 09:00:38 AM

Gotcha, I had done a search on youtube and came across the Biltmore stick and couldn't see how this would relate to cut logs. Thanks

Old Greenhorn · February 05, 2020, 10:40:10 AM

Very good discussion on this here: https://forestryforum.com/board/index.php?topic=42659.0

stavebuyer · February 06, 2020, 06:20:37 AM

Quote from: frazman on February 05, 2020, 09:00:38 AM
Gotcha, I had done a search on youtube and came across the Biltmore stick and couldn't see how this would relate to cut logs. Thanks

Biltmore stick is for measuring standing trees at breast height. There are some "dual purpose" scale sticks that have the Biltmore scale on one side and regular log ruler on the other with corresponding bd/ft tables printed on each face. These tend to be more suited to standing trees although can be used for either and pretty inexpensive.
A folding "4' log ruler" is commonly available with either Doyle, International, or Scribner log rules and is little easier to use. Any ruler will work but the ones with the scale data printed on them come in very handy.