Forgive the lack of levity but I have an actual question which I hope
someone can help with.

I've been asked to look into the possible recasting of some late 19th cent.
Sullivan cast iron decoration.  The fragments of the originals that exist
have the deep indentations, figuring and definition that is typical of
Sullivan's work, truly magnificent integration of decorative and structural
lines.  They are wonderful.

Foundry people I've spoken with are discouraged about the reproductions
because the deep hollows and narrow protrusions are very difficult to
reproduce in sand molds, the standard method for iron casting.  It would be
possible to produce these new elements by ceramic shell lost wax process but
1. it's expensive relative to sand, possibly making the project too costly
and, 2.  it wasn't available when the originals were cast so they must have
been possible to create using the sand cast method, the only procedure then
used.

I know that certain sands once used in foundry work, the so called "French
Sand" which was from a particular bend in the Seine that was extremely fine,
could have facilitated this work if utilized.  It could have allowed for
generally finer detail than what we typically get from sand molds now but
even it would have been susceptible to failure at the deep hollows.  There
the small sand protrusions, surrounded by liquid iron, would have lost
cohesion and fused into the metal before it cooled causing loss of detail.
As no amount of reworking will ever match the sharp lines of the original
models this amount of loss will be unacceptable.

I have been exploring the possibility that the casts were planned to be
extremely thin,  The fractured elements look to be on the range of 1/4 inch
or so thick.  It that was the case, the metal might have cooled rapidly
enough to reduce the deterioration of the sand molds.  The foundry folks are
skeptical.  Most of the fragments available are mounted on museum walls and
curators are loathe to allow access to the backs for measurements.

Before I look into getting an ultrasonic caliper and do a lot of expensive
tests I wonder if anyone has any thoughts or knowledge about this area.  I
would greatly appreciate any help or suggestions for avenues of research.

Mark Rabinowitz
Conservation & Sculpture co.