[Domesteading 00270] Re: Flexible concrete - spraying

[J & D Goldman]

Nolan wrote:
Using a low pressure form (LPF) requires progressive stiffening of the
shell. Normally the lightest
dusting of spray foam is shot then a thicker layer. This building up
the strength of the LPF lets a
person use much lighter and less expensive formwork. In our test dome,
we wanted to step out a
little farther and not use spray foam.
---------------------------------
Very interesting post on the thin shell concrete on airforms.  I'll
spend some time looking at all the links you folks posted.

Just something to pass along for getting the intial thin layers in
place.

I don't know if an ultrasonic nozzle would work with these materials
or make a big difference in performance. They are expensive (4
figures) and basically use a vibrating element to control droplet size
and propel the material.  Not something for the hobbyist, but if one
is going to do this as part of a regular business, or rent machines,
or if it really works and makes a nice job regardless of a lack of
previous experience, it might be well worth the price.  I can post
some referral info if there is any interest - unless you already know
this has been tried and not worth the cost.

- Dan G.