[Cob] Wood "straw" for making cob

[Rob Hayes]

Hello Henry,


I wish we could see that Vermeer chipper blade photos.  I wonder if it had a 
series of notches at the sharp part of the blade.  Maybe the wood was presented 
to the blade in a way to make longer shreds.  It'd be great if we could find a 
way to modify the chipper blades or make some corrugations which would produce 
that "straw-type" wood fiber.  Didn't they used to call this sort of stuff 
excelsior?  There was something like coarse wood straw used for packaging 
fragile stuff and for stuffing old furniture too.  Other olde heads surely 
remember too.
Henry, I've got a small electric chipper/shredder and I'm thinking of just 
ordering some new blades so I can modify them for research.  The objective would 
be to make wood straw and re-learn how.  But, certainly there is something 
already patented which I should see and imitate  first.  If you've come up with 
any ideas about this please feel free.  Before I subscribe to the patent search.
There is certainly some advantages to having longer fibers and some airspaces in 
the cob too, right?  The chips, being shorter length, wouldn't coalesce into a 
likely stabler structure the way you'd like with the longer wood fibers of the 
excelsior, right?



"...The wood wool that is the topic of this article is that which has  
traditionally been known as excelsior in the United States. Fifteen U.S.  
patents related to "slivering machines" for producing small wood shreds  "known 
as excelsior" were listed in 1876.
The 1868 patent "Improved capillary material for filling gas and air 
carburettors"[39] is on a new use for "fibres torn from the wood by suitable 
machinery",  that "is sold and used as filling for mattresses, its commercial 
name  being 'excelsior'." This is the earliest description of the material by  
this name cited by the Oxford English Dictionary, though the term "excelsior 
mattress" had appeared in print as early as 1856.
In the beginning of the 20th century wood wool was used as raw  material for 
production of wood wool panels in Europe, especially in  Austria. By 1930, the 
wood wool cement boards were being widely  produced."...

2.

PS: Is cob being used for the Haiti housing?  I saw the link in your posting and 
I'm wondering about cob being used to build in Haiti.  The Engineers Without 
Borders hypar roof design and cob seems maybe perfect for the walls there too.

Hypar (hyperbolic paraboloid) Roofs
http://tscglobal.net/?page_id=341
"...in the most severe earthquake, TSC roofs themselves would likely exhibit 
little more than lateral cracking."
"An important advantage to TSC Hypar buildings is the minimal to zero need for 
lumber."

see the 14 year old TSC roof being jumped on:
http://www.youtube.com/watch?v=Jx5kcr-7gCU

Surely, the Carter Habitat project allow volunteers and fundraisers too for 
other upcoming dates in Haiti?  The webpage said:
"Please note: The application process for  this year’s Carter Work Project 
has closed. We hope you will be able to volunteer with us soon!"
I'd like to consider joining them after the garlic gets planted on the farm here 
in November.  Do you have a group going Henry?

________________________________
Message: 1
Date: Fri, 15 Jul 2011 17:19:42 -0400
From: Henry Raduazo <raduazo at cox.net>
Subject: Re: [Cob] over oiled floor
To: Coblist List <coblist at deatech.com>
Message-ID: <8A32C534-2B3A-4374-B9F6-CCC796B1B0E7 at cox.net>
Content-Type: text/plain;    charset=us-ascii


I found the answers to questions asked last year and thought some people might 
be interested. 

     First: you may remember I built a wood shed using rototiller cob and  
shredded wood instead of straw. I wondered why Robert's disc style  chipper 
turned willow oak into long straw-like fibers. This year Robert  replaced the 
blades on his chipper and now his 6 inch Vermeer is putting  out fine 1/4 to 1/2 
inch chips instead of 4 inch straw fibers.  Apparently, if you want wood fibers 
suitable for cob you must use a  chipper with a very dull blade.

    Second: I and many other  people have been having trouble with mason bees. 
Mason bees are  beneficial pollinators and non-aggressive, so it was neat when I 
only  had a few of them, but after ten years I was getting hundreds of bees  and 
the population was still growing. I felt this would start  threatening the 
integrity of the wall. 

    Lime plaster and lime  paint seem to prevent the mason bees from attacking 
new sections of  wall, but in places where they are well established, they can 
and will  tunnel through even 1/4 inch layers of lime. 

    The solution is to  hang up a very thin layer of plastic. I used painters 
tarp so thin a 12  foot by16 foot sheet comes in a plastic envelope and weighs 
less than  1/2 pound. This blocked the bees access to the wall and they moved to  
other less critical cob walls on my property or to river banks along the  
Potomac. 


Ed
http://www.habitat.org/cd/cwp/participant/participant.aspx?pid=93541387

________________________________