Acer Negundo

[TexasTimbers]

Trying to figure out what species listed in the log weight calculator would be closest to box elder.

I could say since it is a "soft" maple then I should use Soft Maple but that is not too scientific. 

Can I go by specific gravity (green = 0.416) and just match the sg of box elder closest to one of a listed species?

[beenthere]

Use a Specific gravity value of 0.44, and then go to the density table 3-7b in chapter 3 of the Wood Handbook for the density depending on the moisture content of what you have.

If 12% mc, weight will be 32#/cuft

If 32% MC, weight will be 36#/cuft

If 60% MC, weight will be 44#/cuft

for a rough but scientific calculation....

[TexasTimbers]

Your info using a specific MC is quite scientific. I should have cracked the book. 

[turningfool]

according to my calculations a green box elder log approx 30" in diameter and 30" in length would be too much too lift into my truck then..correct? ..you guys have all kinds of scientific stuff on here ,makes me feel somewhat inadequate..i better read up huh?

[Brian Beauchamp]

Specific gravity is the mass of 1 cm^3 of something divided by the mass of 1 cm^3 of water, which is why it is unitless. Since it is known that the mass of 1 cm^3 of water is 1.00 g, then the conversion of specific gravity to pounds per ft^3 is fairly easy. 1 cm=0.393700787 inches. 12 inches=1 foot. 1 g=.001 kg. 1 kg=2.2 lbs.

lbs/ft^3=(((.416/.393700787^3)*.001*2.2)*12^3)=25.91557808 lbs/ft^3 (dry green)

@ 12% MC=29.02544745 lbs/ft^3
@ 32% MC=34.20856307 lbs/ft^3
@ 60% MC=41.46492493 lbs/ft^3

[Brian Beauchamp]

...just noticed that you said that was the 'green' SG...at what moisture content?

[TexasTimbers]

I have been using the scientific methodolgy of Speculative Guesstimation Formulation but I would like to know my weight better so I don't get any suprises if they do a spot check on one of them.

The next pallet going out has:

Qty              small                       large                   length
1                    16                          17                      60
1                    18                          19                      60
1                    23                          23                      60
1                    22                          22                      27

The end grain reads 32% MC but the cambium (or whatever you call that slick part after you peel the bark off) only reads 18%

I can't cut into these logs they are fixin to be shipped and have no excess length how can I get an accurate MC reading? I am using a Mini Ligno E for my readings.

[Brian Beauchamp]

I'd take several readings on the log and average them, Tex.

[TexasTimbers]

I was just curious about a reading that shows 18% under the bark, and then right around the corner on the end grain I get a reading (under the wax) of 32%. These readings are less than a feww inches apart. Shows the same on every log.

[Brian Beauchamp]

Scale a log and see what it's dry weight is supposed to be...weigh the log and calculate the actual MC, then see which location on the log gives you the best reading...then you should know from there on out the best method for using your MC gizmo.

[TexasTimbers]

Scale a log and see what it's dry weight is supposed to be...

I can't find a scale that even lists the species that's my point. If I am being rediculous about this feel free to tell me. All I want to do is get pretty close to being able to figure the weight of these things for shipping purposes. If I could know for sure a certain maple (or even other) species is close to the same weight category as acer I would be happy.

[SwampDonkey]

I was just curious about a reading that shows 18% under the bark, and then right around the corner on the end grain I get a reading (under the wax) of 32%. These readings are less than a feww inches apart. Shows the same on every log.

Well my edu-guestimate is that the end grain wicks water out the log end faster than out through sides. So there is more concentration of water on the end grain. Also, the xylem part contains mineral salts and the cambium contains sugary sap.  That might make a difference to, due to concentration. Did you compare the end grain of the cambium and sapwood, versus the heart end grain?   

[Brian Beauchamp]

Scale a log and see what it's dry weight is supposed to be...

I can't find a scale that even lists the species that's my point. If I am being rediculous about this feel free to tell me. All I want to do is get pretty close to being able to figure the weight of these things for shipping purposes. If I could know for sure a certain maple (or even other) species is close to the same weight category as acer I would be happy.

...not being ridiculous at all.
Dry weight of A. negundo= ~20.56 lbs/cu ft
Green weight @ 26.7% MC=~28.04 lbs/cu ft

http://www.ncsec.org/cadre2/team18_2/students/dryweightcal.html

[TexasTimbers]

Thanks Brian. I am gonna try to assimilate all this. There is more to it than appears once you start cogitating.

SD yes it was the heart end grain reading but I just took another set of readings and the end grain near the bark was 28%, but I am not gonn alet the low MC% reading off the cambium confuse me. I know the MC is not 18% so I am gonna use the end grain readings.

[SwampDonkey]

  I figured the end grains would be close, but not the same. What's also going on is the drying in the sapwood is quicker because it's obvious it's not as deep as the heart. So, the water has to migrate through less layers to move toward the bark. Both have wicking out the end grain at a similar rate none-the-less.

[beenthere]

Usually the end grain moisture content is lower than further into the log (wood dries faster out through the end grain), and is the primary reason for end-coating/sealing green logs (so the ends don't dry faster and check).
So your end grain moisture content is prolly not to indicative of the internal mc of the bolts.

Also, the moisture meters (if surface contact) will read differently on end grain than on the tangential or radial surface...just something else to add to the equation.

[SwampDonkey]

Yeah I agree, as per my second post back. I was saying that the end grain of sap wood and heart wood have similar evaporation. I also agree that the surface of the end grain dries sooner. Only stands to reason. But the water wicks toward lower water content and migrates to the ends of the stick, but with decreasing rate of movement as you go deeper into the stick. True for lateral movement to. Nothing easy. 

[Brian Beauchamp]

Thanks Brian. I am gonna try to assimilate all this. There is more to it than appears once you start cogitating.

No problemo. There is always more to everything than ya think at first! 

[SwampDonkey]

I am assuming the wood is air dried, so 18 % would be low for boxelder. It holds a lot of water like aspen, where water is about half the weight. 30% would be more realistic for air dried, but not wood that has been in the barn and sawn for several years. You can't compare boxelder to red maple or silver maple. At least the red maple around here is a lot heavier than boxelder when both are seasoned.


Apparently the red streaks in the heartwood are composed of a pigment from a fungus (Fusarium negundi). [Source: USDA, Forest Products Lab Fact Sheet]

[TexasTimbers]

You may be right about the red streaks. I have been told that the ambrosia beetle is the cause of it though. I can tell you for sure though I have never seen a red streak without there being a hole in it somewhere, without exception. Maybe the beetle causes the fungus though and so both are correct.

I appreciate the info on figgerin my weight fellas.   

[SwampDonkey]

You'd be right Tex, that's how the wood gets inoculated with the fungus. We get those streaks here. I just never paid any attention to it much because we always hauled the stuff to the rock pile or some brush pile for burning.  I buried two this fall.