Wood Expansion Characteristics
 

I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

Thanks,

Greg G.

Wood Expansion Characteristics
 

"Greg G." wrote in message
...

I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

Thanks,

Greg G.

I don't have a link like that but here's a cheap alternative:

http://www.leevalley.com/wood/page.a...=1,46096,46109

Wood Expansion Characteristics
 

"Greg G." wrote in message
...

I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm

Of course, as you will discover by reading chapter three, the figures must
be considered averages, because it is the orientation and spacing of the
annual rings which ultimately determines specific movement.

Wood Expansion Characteristics
 

Greg G. wrote:
I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

Thanks,

Greg G.

Greg,

Try: http://www.natlhardwood.org/
specifically: http://www.natlhardwood.org/pdf/Hwds%20of%20NA.pdf

Also, try The Wood Handbook put out by U.S. Department of Agriculture,
Forest Service, Forest Products Laboratory
http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.pdf

The above may not have the specific information you are asking for but
these are great references.

Dave

Wood Expansion Characteristics
 

Greg G. wrote:
I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

Thanks,

Greg G.

Greg,

Individual chapters of the The Wood Handbook are at:
http://www.fpl.fs.fed.us/documnts/fp.../fplgtr113.htm

Dave

Wood Expansion Characteristics
 

On Thu, 29 Dec 2005 15:52:23 -0500, with neither quill nor qualm, Greg
quickly quoth:


I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

I seem to recall seeing that being covered in "Understanding Wood" by
Bruce Hoadley. See your local Librarian!


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Wood Expansion Characteristics
 

On Thu, 29 Dec 2005 21:18:58 -0800, Larry Jaques
wrote:

On Thu, 29 Dec 2005 15:52:23 -0500, with neither quill nor qualm, Greg
quickly quoth:


I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

I seem to recall seeing that being covered in "Understanding Wood" by
Bruce Hoadley. See your local Librarian!


You are correct on that. Table 6.2 gives the tangential/radial expansion
differences and there is discussion following that regarding estimating how
much a piece of wood at one moisture content will move when the humidity
causes the moisture content to change to another value. One could probably
do some worst-case analyses to find the limits using the formulae Hoadly
provides.



+--------------------------------------------------------------------------------+

If you're gonna be dumb, you better be tough

+--------------------------------------------------------------------------------+

Wood Expansion Characteristics
 

Greg G. said:

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity

Doh! What a moron. I used to give out a link to the Forestry Service
PDF that George and David listed, but it moved and I deleted the
bookmark a while back. And then proceeded to forget it ever existed.
It truly IS a great bit of reference material. The book,
"Understanding Wood" sounds like good "library" material as well

Thanks, everyone, for all the links and information. It is precisely
what I was looking for - and more. I downloaded it this time - maybe
I'll remember where I put it. ;-)

Greg G. (looking for the _rest_ of his brain...)


Greg G.

Wood Expansion Characteristics
 

Try the Shrinkulator
http://www.woodbin.com/calcs/shrinkulator.htm

--
Darrell Peart
Author of - Greene and Greene : Design Elements for the Workshop
www.furnituremaker.com





"Greg G." wrote in message
...

I have looked on the web for this information and after 150 or so
sites, most only "mentioning" the seasonal expansion of wood floors, I
am hoping someone here has a favorite link they would share.

I am looking for a reference that details the expansion and
contraction characteristics of various woods in changing humidity
levels. Something along the lines of: "A change from 7% to 15% RH
results in 3.2% expansion cross-grain".

I have found numerous little charts and graphs depicting the hardness
and density of woods, but nothing that deals with their moisture
expansion characteristics.

Thanks,

Greg G.