PVA (Polyvinyl Acetate, commonly known as Vinac *) is a great high quality preservative coating that can be used in all stages of fossil collecting and preparation. We use high-purity, Polyvinyl Acetate Beads (PVA) from McGean Rohco, as a penetrant and coating for fossils in both the field and in the laboratory. We dissolve these odorless, tasteless, nontoxic beads in acetone (approximately one pint of PVA beads per gallon) to make a thick concentrate. This is later thinned with additional acetone for different viscosities for various uses. Thicker solution will work best to slow the weathering if a specimen must be secured for later excavation and extraction. Thinner solution will leave a light protective coating on the surface of prepared fossils.
PVA is probably one of the finest consolidants for porous materials or for a flexible coating on fossils. PVA can also be dissolved with water to create a white glue (similar to children's school glue) or with a 50/50 solution of acetone/ethyl alcohol or even pure ethyl alcohol to create a substitute for "Butvar". We are a distributor of McGean-Rohco®'s PVA beads for quantities needed in paleontology and a variety of other uses.
* Vinac is a trademark of Air Products & Chemicals, Inc.
(they are no longer producing Vinac )
We now stock PVA-15 from McGean Rohco.