Ton estimator ...

[TexasTimbers]

Don't ya just love The Tool Box. It's so handy to be able to plug in the numbers and viola!
Without being able to weigh the logs, is there a formula for determimng how much lighter the logs weigh after lying on the ground for certin time periods?
These have been lying in his yard for four months, have some blue stain (which i don't mind), and he only wants $22 ton for them.
The handy dandy log weight calculator says one particular log weighs 1124.3 lbs. But I'm wondering if there is a way to guestimate how much they weigh now as they surely must weigh alot less.
At this price I don't want to dicker, but if the logs weigh as much as 25% less then I actually paying 25% more than what i think etc. Any thoughts?

[beenthere]

I wouldn't expect the weight to drop much if laying on the ground for just 4 months. If setting up off the ground, then more drying will likely occur, but not too much in 4 months either.
Calculating the weight is, at best, an estimate.  If you want a closer 'estimate', then take a sample and calculate the moisture content and compare that against the density and moisture content used in the 'calculator' (assume wood handbook values were used which are also just estimates and averages). 
If the logs show a lot of surface checking, then some drying has likely occurred, but I wouldn't expect too much.  Species of logs will have some effect as well. Do we know what species?

I'd suggest calculating the volume in bd ft and decide what price you will be paying for the logs with respect to the bd ft yield you might get after sawing.

[SwampDonkey]

Depends on time of year. In our winters up here the weight isn't going to change. But, in the summer if the wood laid for 4 months, some mills would reject it. If it's hardwood veneer forget it, and if it's sawlogs cross your fingers the borers haven't arrived. ;D

[Jeff]

If its hardwood, and it was here, the weight would not have changed much just laid or piled on the ground.  We actually had a forester do a write up for a disclaimer on the weight calculator as it has such wide and wild variables. You could create a calculator for weight reductions if you had before and after moisture content, but to estimate loss of weight according to time would be pure guess. I wanted to use guesstimation, but that would infer there was some basis for calculation.

Here is the note you find on the lumber/log weight calc.

This calculator is useful in providing approximate weights for species, but the user should be careful in how the product is used. Wood varies considerably in weight per constant volume (density) on a regional level and at the local level. That is, the weight of a piece of wood from one area or tree will differ from the same species in the another area. The growth rate is the most significant factor in determining density, with slower growing trees having a higher density (therefore greater weight), than faster growing trees. This is due to the late wood cells (the dark ring seen when a tree is cut) having thicker walls and being closer together than the early wood (lighter wood between the rings).
     Where the board is cut from the tree is another factor, the heartwood portion of the tree (the center portion, often characterized by a change in colour) is composed of dead cells and will be lighter than the sap wood, where the cells are still living. Wood that is cut from the portion of the stem that still has live branches on it will be lighter due to hormones produced by the foliage.

     In different areas, genetics will play a factor in wood density, along with the growing site (moisture and nutrient characteristics of the soil). Where the tree grows on the hillside, eg south facing versus north facing slope, high elevation versus low elevation, areas of heavy snowpack versus light snowpack, constant winds versus sheltered locations all have an influence on the density of wood.

[Minnesota_boy]

Sometimes logs lose weight laying on the ground, some times they gain.  You really would have to weigh them to know which way they went. 

[OLD_ JD]

About the tool box :P...any of you can give me the weight of butternut ???  ...is just not in the list  thanks JD

[SwampDonkey]

Look again JD, it's in the log weight calculator. ;)

[OLD_ JD]

...oupss ..sorry SD....thank's  ;D

[extrapolate85]

Being that you said the wood is blued, I am assuming it is pine. If it is green loblolly pine, it will weigh about 3.6 tons per cunit (100 ft3) in the log form (shortleaf will be lighter by about 5% and longleaf or slash pine will be about 5% heavier), and a cunit will yield better than 800 board feet of lumber if cutting 8/4" (over 900 BF if you are really efficient and the logs are big, i.e., over 16" on the small-end). This assumes nominal "scaled" dimensions and about 4.5% average scaling defect.

If you don't mind the blue stain, then the buyer gets a better deal the longer logs are down when buying by the ton (assuming that the bugs and saprot have not had enough time to get established). If the logs are in a dry and exposed place, they could have easily dropped 6% of their weight in the last 4 months (especially if you have had some warm weather), so the weight could be as low as 3.3 tons/cunit.  

[beenthere]

Musta been some 'extrapolatin' happenin der  ;D

[TexasTimbers]

extra' you are very advertent ;) Yep it is green loblolly. I have talked to him since I made the post and he said we would have access to a scale which suprised me a little. I guess there are little country grain/feed store  operations all throughout our rural area more than I realized. Thanks for this info though it will be very helpful. Especially when cutting my own off my M_I_Ls property.
That does bring me to another question. You mentioned slash pine. My M_I_L has always told me that her dad used to call it "trash" pine and not to cut it. Does that square with what y'all know or not?

Jeff I understand you have to have the disclaimer's but that one is perhaps the most informative disclaimer I have ever read!

[extrapolate85]

Slash pine makes nice lumber. What he may have been talking about is "spruce pine", which I have also heard referred to as "trash pine" and is reputed to make poor lumber.

[TexasTimbers]

I wanted to see how close the weight estimator could get. I typed the log specs into the tool box and it told me the logs would weigh 8937 pounds total.
My weight ticket says the logs weighed in at 9310 pounds - a difference of 373 pounds. That's pretty DanGed close.
I realize it won't always get it that close but it nice to have had some empirical data.