Compression wood in Pine

[Steve Bullman]

I was doing some work on a Pine today....not 100% sure but I believe it may have been an Austrian pine.

when cutting wood of 12" in diameter and larger the wood kept compressing as i was cutting. this always happened about one third of the way into the cut at which point i wouldnt be able to cut anymore and would need to take the saw from the cut. once i did this and returned the saw to carry on cutting it was fine.....almost like the initial cut had released the compression. Im not overly experienced on pines as the majority of my work is on Beech. I'd be interested to know exactly what causes this?

[vduben]

ive had that befor, was the wood deformed on one side like reaction growth?

i always put it down to pine being very sappy and soft....

[Amelanchier]

So when you put the saw back in, I assume you cut some material away to make the saw fit?

 

There is all kinds of interior tensions and forces within wood, just like vduben was showing in his crack photo. His is a result of deformity of radial tensions. Yours must be longitudinal expansion, as you say probably compression wood. The exact mechanics of it are probably somewhere in my degree notes.

 

I'll get a beer and have a look for you.

[Steve Bullman]

Tony. the saw went back in the cut easily

vduben.....the wood was pretty straight...id have expected strange forces at work if the wood had been all twisted

[vduben]

trees can be strange at the best of times!!

did it pinch the saw hard or did you get it out b4 it compressed to hard?

a bit off topic but do you know dave cashman tony??

[Steve Bullman]

it wasnt too hard to get the saw out....it just wouldnt cut

 

and no i dont know him

[Amelanchier]

A beer later and a bit of reading.

In compression wood the cell wall has a helical lignin structure, bit like a wound spring. I'm guessing that once you sever that structure, the ends unwind and fill your cut.

 

As for why it changed back. Er no idea.

 

Don't know the name, but I assume that he's your uncle(?) who works for Mr. Barrell.

I'm not in that leauge yet mate... ha one day.

[vduben]

A beer later and a bit of reading.

In compression wood the cell wall has a helical lignin structure, bit like a wound spring. I'm guessing that once you sever that structure, the ends unwind and fill your cut.

 

As for why it changed back. Er no idea.

 

Don't know the name, but I assume that he's your uncle(?) who works for Mr. Barrell.

I'm not in that leauge yet mate... ha one day.

ahh yeah he is sum boy,

how about mick body or quentin (not sure on the surname but he has a boustache:santaclaus: )

[Alex]

I have similar with willow, had the tree been under signifcant wind or group preasure for light... this is when I have noice this more.. It can also be found on heavy limbs but gravatie gets in the way, you will only spot it when step cutting hand held sections back where the tree has put on reacion wood to cope with the loading. Consult Clause Mattheck's Stupsi and Pauli for more info.. he has also got a new book out but have yet to get my sapeie figures on it yet.

[TreeSpyder]

i think the effect is partially because compression side is the grow side in pines; vs. tension side is grow side in oaks.