Unpainted wood.


Denny Anspach <danspach@...>
 

It has been hard for me to know yet just how to respond to Mike
Brock's relating his experience of having a perfectly good creosoted
post rotted away when put into the ground at his house (:-)). I too
have had the same experience.

Rot will not occur in the ideal environs of wood of 30-35% moisture
content. It will not occur, or be arrested in the wettest of environs,
or if the wood moisture content is <20% . It will not occur in
environs >105º nor <40º. It will not occur, or be severely inhibited
in low oxygen conditions.

How wood generally will likely last or react in any given adverse
environment has more variables than Carter has pills, and a full
treatment requires a book. Suffice it to say that the 4500 years-old
wood Solar boat was found completely intact in the super dry environs
of the Great Pyramid of Cheops , while 1000-1200 year old intact
Viking ships have been found completely intact buried deep in the
wettest of mud at Gokstad in Norway and Roskilde in Denmark.

In the most general way, wood is painted primarily for aesthetic
reasons, and secondarily only slightly less for protection from the
elements- primarily the sun. Water seeps into wood primarily (not
exclusively) from the end grain, and if the end grain is protected,
unpainted wood can exist in pretty unfriendly environments for many,
many years. But then, even if the end grain is not protected, some
woods can survive well unpainted anyway- if they are of species
variably resistant to dry rot fungi- redwood, teak, old growth
American Mahogany, Port Orford cedar, old-growth Douglas fir, and a
wide variety of old growth cedars .

The undersides of freight cars were not painted for the same reasons
that we do not optionally paint the undersides of houses without
basements, the undersides of piers and docks (if we even paint the
topsides at all!), paint wood shingles, and often do not paint house
or barn siding (I personally have done both- house roofs and siding on
the former, and a large barn in the latter)! It is not necessary,
except for esthetics, providing that the proper wood has been chosen
and installed for the particular environment.

As to the rotted creosoted post. Quite often "creosoted" posts were
not immersed or pressure treated so that the fluid could leach deep
into the end grain where it could do some good. In either way,
however, with time, all fungicides (creosote included) eventually
leach away, allowing the inherent rotting process to do its dirty
work. For about 25 years, when I have buried posts in the yard, I
seal end grains with epoxy- which very effectively significantly prolongs the life of the post .

I have a feeling that most freight car decking was old growth Douglas
fir, and flat car decking either of the same, or white oak- both woods
that wear well, and are also relatively pretty dry rot resistant
unless poorly installed.

Denny







Denny S. Anspach MD
Sacramento


Anthony Thompson <thompson@...>
 

In an interesting post, Denny Anspach wrote:
Rot will not occur in the ideal environs of wood of 30-35% moisture
content. It will not occur, or be arrested in the wettest of environs,
or if the wood moisture content is <20% . It will not occur in
environs >105º nor <40º. It will not occur, or be severely inhibited
in low oxygen conditions.
The last of these conditions is crucially important. Low oxygen
or anaerobic conditions will allow wood to survive indefinitely, as the
rotting process requires available oxygen. This is not, of course, the
condition underneath freight car floors or running boards, but it is
important if we consider wood in other environments.

. . . 1000-1200 year old intact Viking ships have been found
completely intact buried deep in the wettest of mud at Gokstad in
Norway and Roskilde in Denmark.
Again, what is important here is that these are
organically-rich muds, in which the surplus organic matter consumes all
the oxygen (which is not then replenished), permitting the wood to
last. But the time scale noted is not as impressive as the small twig
which I have before me as I write: it was found in a mud core from a
small tarn above Echo Lake in the Sierra, resting atop the orange ash
layer from the Mount Mazama (now Crater Lake) explosion of 6600 BC. It
is a bit shrunken but in no way rotted.
It ain't all about creosote.

Anthony Thompson
Dept. of Materials Science & Engineering
University of California, Berkeley
thompsonmarytony@sbcglobal.net


Aley, Jeff A
 

Denny,

I have been led to believe that many box car interiors and possibly floors were of white oak. A woodworker once asked me if I knew where any boxcars were being scrapped (i.e. in the Antelope / Roseville area), as they were often a source of good-quality recycled oak.

Regards,

-Jeff

P.S. How do you recommend I treat the dog-eared cedar fence boards that are so common in the Sacramento area?


________________________________
From: STMFC@yahoogroups.com [mailto:STMFC@yahoogroups.com] On Behalf Of Denny Anspach
Sent: Wednesday, December 10, 2008 10:36 AM
To: STMFC List
Subject: [STMFC] Unpainted wood.


I have a feeling that most freight car decking was old growth Douglas
fir, and flat car decking either of the same, or white oak- both woods
that wear well, and are also relatively pretty dry rot resistant
unless poorly installed.

Denny

Denny S. Anspach MD
Sacramento


Anthony Thompson <thompson@...>
 

Aley, Jeff A wrote:
I have been led to believe that many box car interiors and possibly floors were of white oak. A woodworker once asked me if I knew where any boxcars were being scrapped (i.e. in the Antelope / Roseville area), as they were often a source of good-quality recycled oak.
True for many railroads. SP often specified Douglas fir or yellow pine, since both could be obtained from on-line mills, and are also durable woods.

Tony Thompson Editor, Signature Press, Berkeley, CA
2906 Forest Ave., Berkeley, CA 94705 www.signaturepress.com
(510) 540-6538; fax, (510) 540-1937; e-mail, thompson@signaturepress.com
Publishers of books on railroad history


Denny Anspach <danspach@...>
 

ERRATA:

Ideal dry rot conditions are present when there is 30-35% wood moisture content, versus the diametrically contrary assertion that I posted in error.

Denny

Denny S. Anspach MD
Sacramento


Denny Anspach <danspach@...>
 

Jeff Aley comments-

Posted by: "Aley, Jeff A" Jeff.A.Aley@intel.com jaley95630
Wed Dec 10, 2008 1:13 pm (PST)

I have been led to believe that many box car interiors and possibly
floors were of white oak. A woodworker once asked me if I knew where
any boxcars were being scrapped (i.e. in the Antelope / Roseville
area), as they were often a source of good-quality recycled oak....
I cannot speak to how common white oak would have been in boxcars,
although I do know they were relatively commonplace for flat car
decking. When in the throes of a wanton brain lapse some years ago
(the '70s), the Sierra Railroad dismantled/scrapped in situ a
seriously deteriorated 19thC wood coach in Jamestown. I was there at
the time, and like a vulture I picked over the bones of the car to
cherry-pick some pretty fine pieces of fine old white oak- primarily
from the carlines. This oak now lives on in the very heart of several
fine boats. Fortunately the hardware was saved and eventually would
its way to the then-developing CalStateRRMuseum.
P.S. How do you recommend I treat the dog-eared cedar fence boards
that are so common in the Sacramento area?
Replace them!

Denny

Denny S. Anspach MD
Sacramento