We are preasently building a Mesozoic gallery with many marine
fossils.  Most of which are in plaster and framed in wood.  after they
are mounted in the exhibit we are  plastering up to the frame with
molding plaster (wire mesh underneath) but do not want to cover the
the screws with such a hard meduim (in the case of removal).  We also
would like something that is easier to model over a longer period of
time vs. the molding plaster, which after it set's up it is Set Up.
     In discussions here we have talked about the use of drywall mud.
To me it has all the qualities that we're looking for plus a
consistancy of spreadability that I would like.  Though we do
not know how it would react to the fossils in a closed environment.
Does anyone know how safe it is or anyone who has used it or
have any suggestions/alternatives as to what we can use.
 
Thanks
Scott Clarke
Univ. of Nebr. State  Museum