[Cob] Coblist Digest, Vol 8, Issue 179

[Monica Proulx]

>  Re: Washington DC cob: The experimental wood chip and paper
>      clay wood shed (Henry Raduazo)
>

Henry wrote:

       "David: I am referring to shredded wood produced by a 6 inch wood
chipper. For some reason that I do not understand certain types of
green wood passed through the chipper comes out and fine separated
fibers........................."




I may have missed this in the previous posts, but green wood or not, you
would think that with the wood fibers you could get a better bond between
the fibers themselves and the cob mixture, because of texture of the
shredded wood.  Straws have slippery surfaces but the shredded wood that I
have seen is rough looking, and sometimes shredding creates net like
arrangements of the fibers (with "windows"), which one would think means the
wood fibers would stay put better (with all those windows that cob can get
encorporated into). It sounds like you could easily get away with shorter
fibers with all those potential plusses.  Also, wood contains cellulose
(which has good tensile strength, supposedly better than steel?) along with
the lignin (which is good for shear strength, although how much lignin you
would need in the mix to get this shear strength advantage would be a good
question for an engineer, and maybe it wouldn't amount to anything at all).

Sounds really encouraging.  There's lots of quick growing trash trees that
might be easily expendable (at least out East), and you could use them
young.  Coppice something maybe, for this purpose.  What about using these
instead of straw in straw slip stuff infill??