[Cob] Easier mixing techniques to keep people loving cob

[howard at earthandstraw.com]

Yes, I believe traditionally animals were used, like cows and oxen, often in a shallow pit that ran along the wall that was being built leaving room for the scaffolding between the pit and the wall.  This works pretty well if you need to dig a swale to drain water around and away from the building anyway. 

Howard Switzer, Architect
668 Hurricane Creek Road
Linden, TN 37096
931-589-6513
www.earthandstraw.com
  ----- Original Message ----- 
  From: William Bates 
  To: coblist at deatech.com 
  Sent: Thursday, February 05, 2009 7:55 PM
  Subject: Re: [Cob] Easier mixing techniques to keep people loving cob



  Hello,,,olde timer here,,( Lurques Maximus )

  Has anyone ever used an animal to make COB?

  Has anyone ever heard of a " turn style "?
  It is a gadget that, when a horse or cow is hitched up to it, causes the animal to walk around in the same circular path.

  Years ago there was a guy ( on this site )from England that studied COB in collage. And he said that when they used a cow in this manner, it would make more COB than 3 of 4 cobbers could keep up with.. And that was how they did it 200+ years ago...

  I would think that a 4H kid would be more than happy to lend or rent out a cow or two...
  Also I was thinking that a circular pen, ( race track ), and some pigs or sheep, and a person with a long switch to keep them moving would also work.

  Sometimes the most advanced thing to do, is go backwards.
  bill




  ________________________________
  From: Shannon Dealy <dealy at deatech.com>
  To: Ray Cirino <cobanation at yahoo.com>
  Cc: Cob list <coblist at deatech.com>
  Sent: Thursday, February 5, 2009 3:40:00 PM
  Subject: Re: [Cob] Easier mixing techniques to keep people loving cob

  On Wed, 4 Feb 2009, Ray Cirino wrote:

  I probably qualify as one of the old timers of modern cob, and since I
  teach cob from time to time I've seen a fair number of people going
  through the initial stages of cobbing and have a mixed response to Ray's
  posting:

  [snip]
  > The thing that people don't like so much and keeps cob from growing
  > faster is the mixing techniques. When I learned how to do it, I was
  > turned off, because my hands,and feet were bleeding ever time I mixed.
  > It was from the sharp gravel and straw.

  This problem will vary considerably depending on the local materials
  available, but surprisingly, my feet are generally softer than those of my
  students (I rarely walk around barefoot except when cobbing). Over time
  reflexes have developed which keep me from putting my full weight down
  when my foot encounters a sharp object in the mix. With harsher mixes, my
  hands do sometimes bleed, though I generally make heavier use of the
  cobber's thumb with these mixes, so the problem is often more the drying
  effects of the clay which a daily dose of hand cream deals with.

  > My back, neck, arms, and body was hurting.

  I had these problems when I started, I don't anymore and from what I have
  seen from students it is usually due to poor lifting technique and/or
  failure to adjust the batch size and size of "cobs" to what your body is
  capable of handling. These days I am physically capable of handling
  batch sizes three times what I could when I started and I can do them all
  day long. I got to this point slowly adjusting the size as my muscles
  and technique became better adapted to it. My biggest problem now is that
  as my weight has dropped, I can no longer get traction on the ground when
  I am flipping a large stiff batch (never thought there would be a down
  side to losing excess body fat :-)

  NOTE: This is not some macho thing, larger batches take less time to mix
  relative to the total amount of cob delivered per day, and I have spent a
  great deal of time working out what the optimum batch size was for my body
  in order to mix and apply the maximum amount of cob in a day.

  [snip]
  > earth, not to work and be worn out. Here's a sample of how I see we all
  > could take it to the next level.
  >
  > http://people.tribe.net/raycirino/photos
  [snip]

  My response to the photos:

  - Free, tough plastic "mixing tarps", great!

  - Handles for easier grip. Works for me.

  - Mixing by stepping on the outside of the tarp, fine for very wet mixes
  and high agregate mixes, bad for stiff/high straw mixes (I have used
  this approach for years under certain circumstances). The tarp will
  work to spread your weight over to large an area to allow effective
  mixing of a stiff mix, you need to put the maximum amount of body
  weight in the smallest possible area, so walking on your heels without
  a tarp in the way during the final stages makes an enormous difference.
  Mixing while treading the outside of a tarp is also slower than getting
  your feet in the mix and keeps you from feeling the state of the mix.
  This is a common oversight by many people, having your feet in the mix
  allows you to easily detect problems with areas of the mix as well as
  better areas of the mix so that you focus your time and energy only on
  the parts of the mix that need more work which saves a considerable
  amount of time in creating a good mix. If you find barefoot mixing
  with your particular soil/straws to be to much, you are better off
  switching to SCUBA diver booties, these will give you better feel and
  have far less impact on your ability to mix stiff batches.

  > Comment included with one of Ray's photos:
  > "Without a strong billboard tarp and handles you are getting cut
  > knuckles,

  I can't remember the last time I cut my knuckles, but it certainly wasn't
  from the mixing process, application on occasion does it, but the
  billboard tarp and handles won't help with that.

  > a sloppy area filled with clay that slows down production,

  If the area gets sloppy, much of this is due to water/wet cob spilling off
  the edge which can be a problem with any approach, though water seepage
  through regular tarps is probably worse and may contribute more to the
  problem.

  > the tarp lasts a few mixes,

  I'm not sure where you get your tarps, but half a dozen cheap two
  dollar tarps (on sale) are sufficient for me to do a complete building
  with my local soils/straw, and while coarser sharper soils and straw will
  shorten the life of the tarp considerably I've never seen even a really
  crappy tarp that didn't go at least 15-20 batches with sharp soils. Not
  having put the billboard tarps to the test on some of the nastier soils I
  have worked with, I don't know how it will hold up, though I suspect it
  will do much better based on my limited experience using one at the
  Natural Building Colloquium last Fall.

  > slower mixing time,

  I have to disagree with this one, barefoot mixing on a tarp (billboard
  or otherwise) is faster as noted above.

  > can't pulling cob to building area

  Billboard tarp definitely does this better (it's slicker and less prone to
  tearing when sliding).

  > or roll it into cart,

  I have never had a problem doing this with a regular tarp, not sure why it
  would be an issue. Except in a large group setting, it is usually best
  practice to mix right next to where the cob will be applied, so working on
  your own projects, neither of the above are issues (since you shouldn't
  need to be moving large amounts of cob around).

  > and keep cob from progressing into where it should be. People don't
  > like mixing and this solves that problem"

  This one is a matter of perspective, I like mixing and when I have
  something I need to build, it is my morning "meditation"

  As I said, this is something of a mixed response, I definitely agree with
  Ray on some points and disagree on others.

  FWIW.

  Shannon C. Dealy | DeaTech Research Inc.
  dealy at deatech.com | - Custom Software Development -
  Phone: (800) 467-5820 | - Natural Building Instruction -
  or: (541) 929-4089 | www.deatech.com

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