[Cob] Washington DC cob: The experimental wood chip and paper clay wood shed

[Henry Raduazo]

	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 can not send pictures through the cob list, however if  
anyone wants to see pictures of these fibers I can send a photo  
enhanced version of my original letter.
	Photo number 2 in that essay shows a pile of green willow oak  
shredded and delivered to my house by a friend in the tree business.  
The fifth figure shows some of those fibers incorporated into a T- 
shaped wall segment of my wood shed.  The sixth figure shows a close  
up of a hand full of fibers. The entire batch of chipped wood is not  
this good, but I have no trouble sorting out cart loads that are just  
like short straws only much stronger than wheat straw.
	Wood from dead trees comes out as chips and is probably not suitable  
for cob, but I think this is.
	The third picture in the series shows the means for incorporating  
the chips into cob. I added rock dust to this batch, and the L-shaped  
and T-shaped walls are only 8 inches thick because I only want to  
build the strength required to support a roof. (No insulation is  
required or desired.)
	Later next month I am building a full thickness wall that will  
become the thermal heat sink for  greenhouse. In this next wall I  
will leave out the rock dust because I want insulation more than  
thermal mass and I believe that the wood will provide more than  
enough strength and abrasion resistance for the wall.
	Test bricks show everything that I could hope for in a test brick.  
The only thing left is to build a full sized wall and see how it  
responds to Washington, DC area weather.


Ed
On Sep 27, 2010, at 1:26 PM, drub at pobox.com wrote:

>
> Thanks for the thorough description, Henry.
>
> Some questions ... what is your estimate as to the average length  
> of the wood fibers?
>
> As I'm trying to understand your work, I envision wood chips from  
> using an axe to chop across the grain of a tree.  These chips might  
> result in fibers up to 2.5" long, but are usually shorter.   
> Something like that.
>
> Or, I could also envision the longer fibers of landscaping "bear  
> fur", which could be 4" or 5" long.  I believe this product, on the  
> W coast, is derived from the redwood lumber industry.
>
> Did you do some processing of the chips to break them down and get  
> closer to the individual fibers?  Or did you just use the raw chips?
>
> From what process were the chips generated?  Sawmill operations?   
> Tree trimming operations? Something else?
>
> Many thanks!
> David
>
>
> On 09/25/2010 01:42 PM, Henry Raduazo wrote:
>>     I have finished The experimental wood chip cob and paper clay  
>> plaster wood shed   Useable space enclosed 4 1/2 feet by 26 feet  
>> (two 13 foot bays.. Total cost of materials under $100. Freebees  
>> (cost items that I got for free) four 2" x 8" x 15 foot beams and  
>> two bales of straw.
>>     Using wood chips to make cob instead of straw seems to be a  
>> success.
>>     I want to scale this up a bit by making a full sized wall  
>> before winter. The wall will be made of tiller mixed wood chip cob  
>> having no rock dust or other filler in the mix (only clay and wood  
>> chips). Currently my work day is Thursday, but I can do a couple  
>> of Saturday or Sunday work parties if there is any one in The  
>> Washington DC area interested in learning how to mix cob with
> ... lots of stuff deleted