Adhesive for stone

In almost every recent publication about restoration of stone
objects, I read about crosslinking polymers (polyester, epoxy) used
as an adhesive. In my case, a "weak" adhesive would be more than
enough: I'm restoring a small (48 cm or 18 inches high) Egyptian
limestone sculpture witch was damaged by falling from its pedestal.
Pieces are small and bond areas are big, so there is no need for a
"strong" adhesive. Beside that, a bond with crosslinking polymer
would be irreversible.

The stone is very soft and brittle, so the bonded joint should cause
no stress. The stone is very porous and light-colored, partially
painted. Therefore the adhesive shouldn't leave dark stains. At some
points, a stronger bond is needed; bonds of old restorations had
broken up again. After cleaning, the joints don't fit well anymore.
Old metal dowels have to be replaced. Stress of the dowels had
caused cracks in the stone. The problem will be to find a adhesive
with enough elasticity but not to high cold flow.

My ideas are: starch paste, cellulose ether, dispersions of
(acrylic?) thermoplastics, acrylic polymer in organic solvent (in
this order). For the first two possibilities I've no , for the rest
few references. Who has experiences in this case? Are there any
publications ?

Olaf Pung,
Stone conservator in education at Fachhochschule Hildesheim, Germany

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                  Conservation DistList Instance 11:72
                Distributed: Tuesday, February 24, 1998
                       Message Id: cdl-11-72-016
                                  ***