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boards spliting?

Started by SCSawyer, January 02, 2009, 08:26:20 PM

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SCSawyer

I gotta a question for all you sawyers out there what could the reason be to cause 8" poplar boards to split as they fall of on the roller bed I have had wider ones do this but never anything this narrow ? they seem to split right down the heart and it is only the boards that have heart wood, any answers would be greatly appreciated
Silas S. Roberts , Bluff Mtn. Timber

beenthere

Tension stresses in the tree, that want relief.
The tension in the growth ring builds up each year as the tree grows.
It gets relief after the jolt comes and the split happens.

Sometimes it happens during drying.
south central Wisconsin
It may be that my sole purpose in life is simply to serve as a warning to others

Meadows Miller

Gday

SC i agree with beenthere on this one too mate  ;) It can show up anywhere alot comes down to the tree it came out of like site, growing conditions, age, dia ect you might find that it will only show up in this lot of logs from that block  ;) you will also find around the heart area a big diffeance between the center 4 radius and the later wood in the cell makeup  of the wood ;) ;D

Ive cut alot of 39 regrowth 75 to 80 year old Mountain Ash on a 14" band 84 " h/rig setting up for qauter sawing ive seen 3' dia logs when center spliting it will  pull up to 1' on each flitch on a 16' length on and pre splitting up to 2' in front of the saw line  :o due to tension  you had to watch your feed speed too fast and you could have the band dive into the split and  writeoff a $3k band and too slow and the flitch would drop with 3'to6' togo before the band and piviot around on the hyd wedge n ofbearer preasure roll slap the band and have the same effect  :o :o ::) i use to run at around 90 to 150fpm luckly i never had any dramas  ;D ;D

Reguards Chris

4TH Generation Timbergetter

Tom

That's a sign of tension alright. Cypress is bad to do that.  One of the hardest things to get an offbearer to do is to treat the boards with tenderness.   Boards with tension that are thrown, dropped onto the mill bed or otherwise treated  harshly will split.

Ron Wenrich

I've had poplar split in the wider boards as well.  Although its unusual for a narrower board to split, its all due to tension.  I think we get lulled into thinking that poplar is an easy wood to cut since its soft.  But, there's a lot of tension in tulip poplar. 

Are you sawing through a heart check or the heart?  That could cause some of the problems as well.
Never under estimate the power of stupid people in large groups.

SCSawyer

Im sawing threw the heart but have tried lots of different ways but I think it have to do with what my grandpa said about cuting it at the right time then sawing it at the right time he did eveything by his bible [ almanac] and it seemed to work  8)
Silas S. Roberts , Bluff Mtn. Timber

WoodMiller

I agree that Poplar tends to have a lot of stress, maybe because it grows so fast and has a lot of free water (have seen water running out ahead of the blade in the summer. )

Tom - good point about the tailman.  I've threatened to fire mine several times, but he works so cheap it's hard to choke out the words..... So I just nicely ask my 78 year old dad to have a little respect for the old wood.....
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Meadows Miller

Gday

And welcome to the forum woodmiller ;) ;D ;D ;D 8) pull up a pack an hava chat anytime mate  ;) there are plenty of top Blokes with alot of good advice  ;) ;D ;D

with the poplar ive only ever cut around 5000 bft of it as a litle experement for one of the blokes i managed a mill for i found it had alot of free water in it also  ;)  nice stuff to cut  ;D The Poplar we've got down here was originaly planted Briant and May for match sticks    ;) and has been left untended for the last 20 years there is about 1200 ha in Victoria but a market for it is the hard thing to find  ;)

Chris
4TH Generation Timbergetter

Ron Wenrich

I believe the poplar you have to be of the Populus specie while the poplar we're talking to be is tulip poplar which is the Liriodendron specie.  Tulip poplar is in the magnolia family.  Both are fairly softwood, but tulip poplar gets a lot bigger and is more dense then aspen poplar.
Never under estimate the power of stupid people in large groups.

Meadows Miller

Gday

Ron i think your rite mate i think  the stuff we got down here is a european species inm not too sure i think it gets planted as cuttings  the lot i milled was 10 to 26"dia 12' lengths verry white sapwood and some dark brown staining in the butt logs the trees where 50' to 80' tall and about  20 years old  ;) ;D

Reguards Chris

4TH Generation Timbergetter

SwampDonkey

I found this paper as a reference in "Wood Tech".


Stem Anatomy of 30-Year-Old Yellow-Poplar

Authors: Foulger, A. N.1; Vimmerstedt, J. P.1; Eichar, Cynthia1

Source: Forest Science, Volume 21, Number 1, 1 March 1975 , pp. 23-33(11)

Publisher: Society of American Foresters


"Mean radial diameter of vessels and fibers increased from top to bottom along the sheath of wood formed during a given year. Tapering of vessel diameter along the stem may be important in understanding water movement velocities in tree stems."

Might have something to do with the tension.
"No amount of belief makes something a fact." James Randi

1 Thessalonians 5:21

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