Frozen wood. Stronger or weaker below freezin?

RopeShield

RopeShield

Carpal tunnel level member
Location
Ontario, Canada
Back at it today with minus 15 to 20 degrees Celsius or 0 degrees F not including wind chill.

Taday was a major crown clean/reduction of declining mature Sugar maple. Whole tops dead with one lead all punk.

All day observation of the cut,hinge,snap and deflection of limbs leads me to believe that frozen wood is stronger. It may not have the same dynamic bending strength though.

Could be right mb wrong. No real research can be found.

I know the word strong is a bit subjective and qualitative but that seeems to be what I am experiencing..
A thread of frozen wood was being batted around last winter, couldn't find it..

What are you experiencing. Anyone care to share what they experience or know about frozen trees.
 
I often slab wood during the winter. It is definitely becomes frozen. I would also say that it adds strength. It becomes easier to cut but becomes more dense.

But the dynamic of live trees does bring up an interesting subject. First I would suppose that the dynamic is different in all trees. Ranging from sappy to dry (like ash) to live and well trees to dead and dried out trees. I would think the less water in a tree the less change to temperature it would have. In thinking about it and the nature of trees my guess would be to use caution at the smaller tips of branches in the winter due to the lack of ability to bend and thus snapping off in an unwanted place. But as for thicker areas of the trunk and branches at their base should be even more stable due the added hardness due to being frozen. Sorry I don't have any scientific proof to back up my theories.
 
Did anyone else see the Mythbusters episode with the frozen sawdust boats? Wood fiber and frozen water are a winning combination, if strength is what you are looking for.

SZ
 
I know frozen dead wood explodes nicely.

I think just the act of moisture in the wood fibres freezing will add density too it, it would give it more compression strength, but I'm thinking the tension strength would weaken due to less flexibility.
 
My experience with frozen White Pine branches is that they are very brittle and it doesnt take make strokes of the handsaw before they pop off.Not sure about the science of it but sure different scenario working pines in warmer temps.
 
[quote
I think just the act of moisture in the wood fibres freezing will add density too it, it would give it more compression strength, but I'm thinking the tension strength would weaken due to less flexibility.

[/ QUOTE ]

Actually water expands when frozen so the denisity decreases. That is why ice floats instead of sinks.

At a cellular level expanding ice crystals within the cell destroy the cell walls leading to the collapse of the cell. That is exactly what happens with frostbite.

Further as the water outside the cells expands it can and does separate the fibers of the wood. I know there is a lot of varied opinions on frost cracks but expansion/contraction of extra-cellular water is a primary suspect.

Of course trees have developed anti-freeze processes to deal with winter but sometimes the cold just happens so quick the tree cannot keep up with it.

I know that once we start getting temps down towards the 30's (f) and below our hinges do not act as they do in summer, especially when swinging side leaners.

if I had to guess i'd say that the tensile strenght is somehow altered.

Just my two pennies' worth.
 
http://www.fpl.fs.fed.us/documnts/fplgtr/fplgtr190/chapter_05.pdf

There is in this document a study on temperature and wood strengths. You will find an increase in wood strength with decrease in temp especially below freezin.Temperature, moisture content and density is some of the variables.

Ice in wood cell cavities in clear wood add strength.

Hope this adds your body of knowledge and I will do my best to share any more observations and any new insights.

Cheers
 
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