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Q & A: capillary forces in wood

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Most recent answer: 03/07/2016
Q:
when a piece of dry wood (pine) is halfway submerged in water how high will the water raise in the wood
- Chris (age 55)
Strand Western Cape South Africa
A:

It will take some time for the water to penetrate the wood.   But assuming the wood is porous, eventually the water should get absorbed to a level well above the level of the water on the outside.... due to the capillary effect in which the water is attracted to the sides of the pores in the wood.    You can see this effect by holding a drinking straw in water; the water rises in the straw to a point where the weight of the water is supported by the capillary forces between the water and the sides of the straw.

See also https://van.physics.illinois.edu/qa/listing.php?id=2219

 

There are experiments along these lines; see http://link.springer.com/article/10.1007%2Fs00107-009-0359-4#/page-1

 

My memory is that capillary forces in wood are how trees get water to their highest points.  This suggests to me that your pine samples will -eventually- become fully saturated.  But I am not a botanist, so take that with some caution.   You could do an easy experiment using a paper towel instead of a chunk of pine.

Richard


(published on 03/07/2016)

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