[Cob] Subject: Earthbag

[Alexander Ihlo]

 Hi Dan,

I built a small garden wall with "superadobe" filler, aka "stabilized"
earth, in between cordwood logs.  I didn't use bags though, instead,  I
wanted an earthy look so I simply used the mix as a mortar, it creates a
hard surface that wouldn't wash out in big rain.  If I knew how to do cob a
little better i'd have certainly done that but hopefully I learn that more
throughout life.

Using the superadobe idea I created a sort of Northeastern Adobe mix with 1
part cement, 3 parts clay from the local gravel pit, and 4 parts subsoil
from my garden site.  this mix I found while doing trials:

1.  create mixtures of varying ratios of water and solids in plastic cups
2.  let them dry in the shade, and out of rain i guess if that's problem for
you, for two days
3.  get the samples out of the cups and compare them immediately, if some of
them stuck to the bottom of the cup, was it you not mixing thoroughly
enough?  or is it the mixture itself?  you have to do multiple trials to
make sure!
4.  then drop the hardened samples into water for a little while and observe
how they react, Which ones fall apart?  don't use them,
5,  you may also want to think about color, i used the 3:4:1 ratio that I
picked because I liked the clay color rather than the dark grey clay fill
you get at a gravel pit (though the clay filler loves to bond with cement!)

Anyway, I don't live in Puget but that is the process I used and it worked.
I use the tarp and stamp method for mixing, removing rocks as I step on
them.  Then just plopped it on when it got to be the consistency I could
work with, not too goopy, not too stiff... there's a fine line between the
two so be wary.

It's been 4 months only but steady rain hasn't budged the wall, and it's
hard as hell.

From,

 Al