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Grading and permissible bark

Started by postville, April 11, 2012, 09:30:31 PM

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postville

What amount of bark is allowed when grading upper grades before it is considered a defect?
Another grading question- is American Elm considered the same as Red Elm? Hard to tell apart by the bark, but the lumber does look different.
Thanks, Bob
LT40 25hp Kohler, Gehl 6635, Valby grapple, Ford 4600, Farmi winch, Stihl saws

WDH

Can't answer your scaling question, but american elm and red elm are separate species.  American elm's leaf is smooth while red elm's (slippery elm) leaf is sandpapery rough. 

There are several ways to tell the bark apart.  At least in the South, american elm has very deep furrowed diamond shaped ridges.  Red elm's bark is not as deeply furrowed, has less distinct diamond shaped pattern, and the ridges almost look like scales the shape of the end of a tongue depressor.  This bark pattern is very distinct, a least in this area.  The other way is a little more complicated.  The outer bark is called the rhytidome.  If you make a cross-section through the outer bark and look on the cross-sectional surface, in american elm there will be narrow, light colored tan lines.  There are no such narrow tan lines in the rhytidome of red (slippery) elm. 
Woodmizer LT40HDD35, John Deere 2155, Kubota M5-111, Kubota L2501, Nyle L53 Dehumidification Kiln, and a passion for all things with leafs, twigs, and bark.  hamsleyhardwood.com

Ron Wenrich

Bark isn't a defect.  It isn't scaled into the volume of the log.  Scale is taken inside bark on the small end. 
Never under estimate the power of stupid people in large groups.

chevytaHOE5674

Are you talking about included bark within the white wood? As in a double hearted log with bark between them? Or an overgrown seam with a "Bark T" in the end?

As Ron pointed out scaling diameter is small end inside the bark. But if you have bark within the white wood then it will effect log grade.


postville

I corrected the question this morning, it is grading I am talking about.
How much bark on a board before it is a defect. My problem is how close to edge a board. You sure can waste a lot of a flitch getting all the bark.
What about included bark that is on one side of a board and will plane out?
Bob
LT40 25hp Kohler, Gehl 6635, Valby grapple, Ford 4600, Farmi winch, Stihl saws

beenthere

Assuming you are talking about NHLA lumber grading rules, then the grade is based on a number of clear cuttings that have minimum sizes and make up a percentage of the board after it is edged and trimmed. No defect allowed in those cuttings (that won't plane off). In addition to what percent of the board is in clear cuttings, there are certain manufacturing rules that apply such as amount of wane that can be left in total along the edge.
Edging all the wane off for clear edges is likely a waste, although the boards will look good and well manufactured. Just the board scale will be lower.

Are you selling grade lumber? Or just trying to decide how close to edge off the wane?
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

york

you could also get the little book,called "log rules" from northeastern loggers association,inc.
315-369-3078
albert
Albert

beenthere

york
Does that log rule book include lumber grading too?
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

york

nope,just logs-covers doyle,scribner and international-only 28 page,worth having-mine printed1994,third printing.....
albert
Albert

Larry

The short answer is "Wane shall not exceed on either edge of the piece over one half the length in the aggregate." straight from the NHLA rule book.  There are exceptions for some species and grades. 

You might want to check with the buyer first.  I sawed a load of walnut one time where I pushed the wane rules.  I lost grade because the buyer had his own wane rules.
Larry, making useful and beautiful things out of the most environmental friendly material on the planet.

We need to insure our customers understand the importance of our craft.

Ron Wenrich

What Larry said about the bark rule.  I also believe you are allowed 1/3 the width of the board for the F1F or Sel grade.  FAS allows only 1/12 the surface measure in bark or wane.  I wouldn't push it too hard in today's market.

As for the elm, I believe all elm is lumped together for lumber purposes. 
Never under estimate the power of stupid people in large groups.

postville

Thanks, I am sawing for a customer who keeps saying no bark as his customers stay away from any board the has it. I am filling his order and I will just adjust the price to reflect the loss in volume by trimming so close. Order is for a mix of elm ,oak, hickory cherry and walnut. Nice to get some facts on the NHLA rules.
The red elm is really nice looking. I am sawing some from trees that had lost their bark. Nice to salvage something other than firewood from these. Most had 40 feet of log before the first crotch.
On another topic, I really became a believer in the Woodmizer after a job sawing 100,000 bf of basswood. My loader driver was not familiar with my type of hand operated skid steer and sometimes really let a big log hit hard on the bunks. Nothing moved, no breakdowns just steady sawing for 9 weeks.
Bob
LT40 25hp Kohler, Gehl 6635, Valby grapple, Ford 4600, Farmi winch, Stihl saws

Okrafarmer

yes, in that case, I would charge more for "no wane". Of course if it is the bark itself that bothers him, you could take it off with a knife or other tool. You would still have wane but not bark. Sounds like a nice little order you have there. I like it when people want to buy multiple species.
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