I asked an Archaeologist one day if there was a way to save the shards that I find on the beach from crumbling over time. She told me… Pottery Shards are very pores, and when they have been in salt water for many years, the salt gets inside of the pottery, and since salt is a drying agent it could over time make the pottery crumble. She suggested that I soak the pottery shards in half distilled vinegar and half distilled water in a glass jar with a lid for a week or so. She explained that the vinegar was a drawling agent and it will drawl the salt out of the pottery. When you take the pottery out of the jar it will have a slight vinegar smell to it but the smell goes away in a few days. She told me that this will not change the pattern on any designs on the pottery if there is any left, remember when we dye Easter eggs we use the white vinegar to set the dye on the egg.