6 CONCLUSION

Each mold-making process presents very unique challenges. In a visual comparison, the latex rubber mold and plaster cast achieved excellent detail and aided in the subsequent technical study. The selected rubber latex used in conjunction with a cyclodode-cane barrier had minimal surface effects in protected areas, and the latex itself affected only water-soluble soil components on the stone surface. This combination of new (cyclododecane) and improved old (ammonia-free latex rubber) materials and methods shows some promise, although any future molding attempts should always be preceded by careful testing. Unfortunately, latex rubber is inherently unstable, but mold life might be prolonged by careful storage planning. The question of cyclododecane residues remains. Research to date suggests the amounts are extremely small and would be detectable or at least identifiable only by more sophisticated analytical methods. In any case, the amount of residue left by cyclododecane is minimal in comparison to residue amounts left following the removal of resin barriers.

Fig. 7.

Molding sequence: a, bust covered in plastic wrap (Saran) and modeling clay with dam division across center; b, mother mold partially removed from rear to show clay thickness; c, preparation for first molding layer with warmed cyclododecane to left, rubber latex foreground; d, application of 90% cyclododecane in naphtha; e, bust coated with latex rubber layer; f, mother mold fit into position in preparation for RTV pour; g, final composite rubber mold (latex rubber inner and urethane outer) with keying to mother mold; h, plaster cast of original marble bust