This
method is suited to taking imprints of inclined, vertical or
overhanging models, generally when they are large or when it
is not possible to move the model.
Apply
a thin coat of
release coating to the
model to make it easier to demould.
Apply
the first coat of RTV that is either thixotropic or otherwise
made thixotropic through an additive with a brush (impression
coat).
Without
waiting for the RTV to cure completely (after 1 to 4 h depending
on ambient temperatures) apply thenumber of coats that are
required to obtain the finalthickness (generally 1 to 2 coats)
Accentuated
undercuts will be filled with an RTV paste before producing
the shell. Leave to cure for 16 to 24h at room temperature.
Mark
off the membrane several centimeters around its edge and apply
a release agent to the outer surface.
Make
the supporting shell
in plaster, polyester or in
epoxy/glass fabric.
Dismantle
the shell and the membrane.
Reposition the membrane in the shell before reproduction.
