This might be off the wall, but couldn't you leave it in a paste (bees wax?) until you need it. then remove the bees wax. The wax would provide a O2 barrier yet not affect the silver. I am guessing on the wax, I don't know if it will harm it or not. -- John Allen Country Metals, LLC (856) 542-4316 (cell) (856) 504-0087 (fax)