Amount of wood in a log

[Tom Dunn]

If you don't have access to a timber scale(I think thats what they are called), how can you estimate the board footage in a log by just the length/diameter dimensions?

[jeff...]

Lot depends on log grade, but here's a few calculators. Just make sure you measure you diameter inside the bark (DIB).

http://www.forestryforum.com/calcs/sawlogbf.htm

Doyle scale shorts a 4x4 or 6x6 out of the log to account for pith. It's the scale I mostly use since the pith ain't any good for furniture lumber anyways.

Thanks

[DaveO]

Tom, it's all wood in a log...there ain't nuttin' else but air in there.

Here are some really good on-line calculators to help you determine how much wood you got in a log and other interesting things. http://www.woodweb.com/Resources/RSCalculators.html

One thing to note is that there are several "scales" that determine log volume. They vary widely in their results. I don't know which is truest or the most realistic for real-world sawing.

Dave

[jeff...]

Originally Posted by DaveO

Tom, it's all wood in a log...there ain't nuttin' else but air in there.

Here are some really good on-line calculators to help you determine how much wood you got in a log and other interesting things. http://www.woodweb.com/Resources/RSCalculators.html

One thing to note is that there are several "scales" that determine log volume. They vary widely in their results. I don't know which is truest or the most realistic for real-world sawing.

Dave

Dave I have closely considered this myself and for a band mill with a 1/8 kerf here's what I concluded.

International scale for softwood where you don't care about pithy lumber
Doyle scale for hardwood where pith is no good for lumber.

Consider a 20" dia - 8' long log

* Doyle = 128 BF
* International = 145
* a difference of 17 BF
* 5x5x8 is 16.6 BF

For hardwood that would be a 5x5 pith ridden piece of firewood. But if it were pine it would be an acceptable 4x4 and a 1x4 or a couple of 2x4 and a 1x4. I guess what I'm trying to say is there is an acceptable amount of pith allowed in hardwood but it's unlimited in softwood, just take a look at some BORG pine and you'll see what I mean.

If I were to estimate hardwood lumber from our example log - I would quote the Doyle scale, if it came up more than that it would be all that much better but I still would be mindful of the amount of pith in the lumber.

Later

[DaveO]

Jeff, that is good to know. I have always consider the Doyle scale to be most real-life accurate because like most things in life anticpating less is best so you can be surprised with more.
Dave

[jeff...]

Originally Posted by DaveO

Jeff, that is good to know. I have always consider the Doyle scale to be most real-life accurate because like most things in life anticpating less is best so you can be surprised with more.
Dave

That's why I like you Dave - always thinking on the positive side - I need to be more like that. Then maybe I could be top poster (yeah right)

[DaveO]

Jeff you are second in command in post count...now you would have to more than double your posts to top me but you are still the closest second
You can do it!

Dave

[jeff...]

Originally Posted by DaveO

Jeff you are second in command in post count...now you would have to more than double your posts to top me but you are still the closest second
You can do it!

Dave

[Tom Dunn]

it's all wood in a log

Indeed!

Just FYI:
This question came to mind because some folks(well, mostly me, actually) were pondering the feasibility of purchasing raw logs, off site of course, to construct a traditional log cabin.
Without some idea of the amount of lumber in a log, you could't even begin to estimate the value of a log of given species and size.....

[jeff...]

Originally Posted by Tom Dunn

Indeed!

Just FYI:
This question came to mind because some folks(well, mostly me, actually) were pondering the feasibility of purchasing raw logs, off site of course, to construct a traditional log cabin.
Without some idea of the amount of lumber in a log, you could't even begin to estimate the value of a log of given species and size.....

It's possible, but for a log cabin I would not purchase saw logs. There are lower grade logs that would do fine. might want to google some stuff up and do a little research... I know there are all kinds of new fangled ways out there to dress logs to be joined together, mainly T&G or some variation of it. My thoughts go back to "the day" and the question I ask myself is newer better? Lots of old cabins are still standing today that used old methods of construction but then again lots of newer cabins sure do look nice and go together easier.

Good Luck... I think you'll need a crane - could be a tool gloat coming up - hu?

[Tom Dunn]

I think you'll need a crane

I doubt this cabin idea will ever get past the "ponder" stage, truth be told. That said, I've worked on a few remote cabin projects. Long ago. No roads, power.
SOP was for the builder to select a sufficiently stout tree on the cabin site, top it at the proper height, and use it as an anchor for ropes, comealongs, and such to place the courses. Tree ends up in the center of the walls, then is dropped, bucked, and removed.

[titan04]

Originally Posted by DaveO

Tom, it's all wood in a log...there ain't nuttin' else but air in there.

Here are some really good on-line calculators to help you determine how much wood you got in a log and other interesting things. http://www.woodweb.com/Resources/RSCalculators.html

One thing to note is that there are several "scales" that determine log volume. They vary widely in their results. I don't know which is truest or the most realistic for real-world sawing.

Dave

I have grossly underestimated the amount of logs I have cut down... I should have known the guys estimate of 300bf for one oak log was off when he couldn't pick it up with his tractor.

I have one oak log that would estimate 676bf on the Boyle scale...

I am out of room and none has been milled... yikes

[AndyBarnhart]

It seems like it would make more sense to subtract some small percentage for pith instead of a static size, for small time guys like me. I have some holly that was harvested at the curb and the biggest log was only 8".

-Andy

[jeff...]

Originally Posted by arbarnhart

It seems like it would make more sense to subtract some small percentage for pith instead of a static size, for small time guys like me. I have some holly that was harvested at the curb and the biggest log was only 8".

-Andy

Andy the difference between the scales (International verse Doyle) is linear. Until I think it's around 29 ~ 30" diameter, then two scales start to equal out. Keep in mind there is only so much "good" wood in a small dia log. You would be very lucky to pull a few 6" wide boards off a 8" dia log. More realistically your looking at a 4 and 5's, depending on how straight the log is. I try my best to make it a rule of thumb, not to cut anything less than 12" diameter. there just ain't enough good wood to mess with in anything smaller. A lesson I learned is to always stick your logs on the Doyle scale. If you come out a little over when you cut them, great, but in all honesty Doyle is more accurate when you factor in pith and cull from drying defect... This is strictly speaking of hardwoods. Softwood (pine) is a completely different ball game. Pith is not so much of an issue in softwood as it is in hardwood. Just take a look at some BORG pine and you'll see what I mean.

Thanks

[AndyBarnhart]

The few tiny holly boards I got for almost no effort were worth it for me given the cost of holly (and it is hard to find small boards sold a few at a time for anything other than retail) and the application (citole frets, tuning pegs and maybe some inlay). They cupped and twisted but are still fine for my purposes.

Oh yeah, I am quite familiar with BORG softwood. A few days back I got a nice QS clear spruce 1x7 suitable for making tops for string instruments that was set to the side of the 1x10 pile because one edge (where the center rings were) was full of cracks. There was a supervisor nearby when I checked out and he offered me a discount since it was in such bad shape.