Cob: ants and mortar mixers

[Jeanne Leimkuhler]

Wow, a simple little ant problem sure has spurred a lot of activity on the
list. We are also currently working on a cob building and have found ants
burrowing into the top of the wall and building nests. We just sprayed the
area with the hose until they realized that they had to leave or drown and
then packed that area with cob. Problem solved, for now.

What I really wanted to write about today is the wonders of a mortar mixer.
We have been cobbing since last fall on our building and although I think
foot mixing is fun, good for your body, quiet and definitly a more pleasant
experience all the way around, I am amazed at the efficiency of the mortar
mixer. My husband, Joe, purchased an old beat up mixer from a local
contractor, that wasn't running, for $50.00. He had to sand blast the old
mortar off, take off the paddles and cut new rubber scrapers, straighten
the main shaft and do some small engine repair. But damned if he didn't get
that thing running and we tried it out last Saturday. It mixed cob so fast
that we were barely done putting the first batch on the wall before the
next batch was ready, and the batches are twice as much as we were able to
mix on a tarp. This will totally change our building experience. This is
our third year of weekend building on a guest house for some friends and we
are ready to move on to other projects. Now I can actually imagine us
finishing this building in the near future.

I have a couple of questions for anyone with mortar mixer experience.
First, the cob is not getting stomped, so I'm not sure if the clay
particles are getting flattened out like they are supposed to. We found
that the mixing worked best if we put the clay in first with enough water
to break down all of the clay lumps. When is gets really creamy, we add the
sand. Is this doing the same thing as stomping the clay?
Second, When we add the straw into the mixer it seems to be breaking up the
straw into smaller pieces. Since we want the straw to stay as long as
possible, does anyone have a technique to keep this from happening?

Thanks,
Jeanne and Joe
Bloomington, IN