PVA Vinac Beads
PVA (Polyvinyl Acetate, commonly known as Vinac™ *) is a high quality preservative coating and consolidator that can be used on a huge variety of fossils. We use high-purity, Polyvinyl Acetate Beads (PVA) , as a penetrant and coating for fossils in both the field and in the laboratory. These nontoxic beads are dissolved in pure acetone (approximately 1 part PVA beads to 8 parts Acetone) to make a concentrate. This is later thinned with additional acetone for different viscosities for various uses. A thick solution will work best to slow the weathering if a specimen must be secured for later excavation and extraction, or for keeping fragile bones and teeth together. Thinner solution will leave a light protective coating on the surface of prepared fossils, and is commonly used on fish from the Green River Formation.
PVA can be dissolved with a 50/50 solution of acetone/ethyl alcohol or even pure ethyl alcohol to create a substitute for "Butvar".
Mix 1 oz. PVA Beads with 8oz. of Acetone for most uses.
* Vinac™ is a trademark of Air Products & Chemicals, Inc