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Grade

Started by Rob, December 29, 2002, 03:08:27 PM

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Rob

I was just wondering if someone could tell me how exactly do you determine the grade of logs I always hear people say #1,#2,premium etc..Also what does heart like 1/3 heart,1/4 heart refer to??and 3,4 clear face what does al this mean.Just looking for some good info..

                            Thanks

beenthere

From what I know, there are standard published Forest Service (Sawlog) Log Grades that were established in the 30's, and for which there are published yields of standard NHLA lumber grades. The definitions of clear faces, requirements for each grading face (four to a log) which are predictors of graded lumber that can be recovered below the face, and acceptable cull and sweep (as defined by Forest Service scaling handbook) are spelled out. There are three grades for sawlogs. The grades used most often are renditions of these grades that may be easier for application in the field by sellers and buyers. Often the grades are setup by the buyers of logs, and depict what they want to establish for payment of logs. Veneer buyers have veneer grades, and tie buyers have a different set of grades.
If you are sawing logs for grade, and want a solid set of rules, look for copies of the Forest Service grades (you will also get the yield figures and can evaluate your sawing recovery against those yields).
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Ron Wenrich

In my area, you can get different grade descriptions from nearly every mill.  Some mills call a premium log as a clear that won't make veneer.

Usually, the better grade logs with 1 or 2 defect will get to be a #1, but it also depends on log length and diameter.  #2 logs often have 2 clean faces.  Then you also get into a 1A or a 1B class.  A #3 is often just a log that won't make anything else.  It could be due to being too small.

The USFS has log grades published.  They are graded on the 2nd worst face.  I've graded logs like that, and it also depends on the spacing of the defects.  Most loggers don't understand the grade, so it will have to be spelled out each time.

As for the predicted yields, it is smart for a mill to do yield studies, no matter what the grade of the logs.  It will help set realistic grade and value to logs.  I have seen the USFS results, and I wouldn't use their results for some of our species.  I would want to get my own data.

Defects may or may not be a problem.  Some will saw out, some won't.  The best log graders are sawyers (right Jeff?)  Each mill has different grades and each grader will be different.

As for the 1/3 or 1/4 heart, that refers primarily to white woods, where heart seems to be a problem.  Ash, birch, maple, and tulip poplar are limited in the amount of heartwood.  1/3 means that a 21" log would only be allowed to have 7" of heart.  Again, varies by grader and market conditions.

Some veneer species can be rejected due to too much sap.  Cherry in particular.  They only want to see a small band of sap, since it is seen as waste.

The 3 or 4 clear face sawlog is usually an export sawlog.  It means it has to have 3 or 4 clear faces.  
Never under estimate the power of stupid people in large groups.

Rob

Thanks for clearing that up for me guys I really appreciate it  ;D..

                             Thanks Rob.

Ron Scott

Ron W. is right on. Study the grading specs. published by the USDA-Forest Service etc. and then practice, practice, and watch logs by species run through the mill. That's where and how most of the Forest Service studies were done.

The sawyers are worth their pay as they are the "best" log graders. That's why they get the big $$$  ;)
~Ron

Rob

Thanks Ron,I went on the USFS/USDA website and have been searching around all morning trying to find the specs for grading but I cannot find anything.Do one of you guys think you could post a link or help me out here I would really appreciate it.

                             Thanks Rob.

Ron Scott

Rob,

At the USDA-Forest Service site go to the Northeastern Research Station Link or to www.fs.fed.us/ne and at the Site Index search for the log grading specifications. You will find it there in several sections.
~Ron

Rob

Thanks Ron I finally found it..Now all I gotta do is a little printing..Thanks Again

                         Rob..

Ron Wenrich

You might be interested in looking at the tree valuation calculator over in the toolbox (the red thing there on the left banner).  That was written using the USFS tree grading guidelines.

To get the value of a tree,  you simply grade the best 12' of the 1st log of a tree.  You also need to know the lumber value of 1 Common lumber.

I wouldn't use it to buy timber, unless you knew how close your yield is to the USFS grades.  Not all mills saw the same.  I believe their results are from live sawing timber.  Most mills saw to a cant.

The most important job in the forest products industry is the bucker.  He determines the value of every board that is cut from the logs.  If he screws up on grade, every board is effected.

As a sawyer, I can only try to get the best yield out of any given log.  Give me a junk log, I'll give you junk lumber.  The bucker must give me the highest valued logs from a tree.  
Never under estimate the power of stupid people in large groups.

beenthere

Ron W.
.  I believe their results are from live sawing timber.  Most mills saw to a cant.

The lumber yields for the Standard Forest Service Log grades were from conventional sawing for standard hardwood grades. Not live sawing the logs. There were, if I remember correctly, some studies comparing live sawing yields to grade sawing yields, but that was later in the early 60's. The yields were not optimal yields, but yields from well-run mills in many Eastern states. (I used to know the lumber grader and tally man that put the original yields tables together by the name of Wally Wollin). Also, Coley Vaughan (died two months ago) was heavily involved, as was Lee Hanks are names I remember.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Ron Wenrich

Maybe I should say that their sawing was down to a dog board.  There was no blocking and everything went into boards.  If I recall, they also used different thicknesses in their run.

Sawing blocking will change the yield as will different thicknesses.

Their methods of developing pricing and yield structures based on mill analysis is a good one.  Too bad more mills don't use them.
Never under estimate the power of stupid people in large groups.

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