Hi, was visiting my mom this weekend and she has an old serving tray that almost all of the silver plate is gone and she would like to remove what little is left so she can polish it up for a nice copper serving tray. problem is there is an etched or carved pattern in the copper and I think steel wool may damage it some what. so I was wondering if there was a cheap chemical way to remove the silver and preserve the copper? something that's not over the top to do. we have tried vinegar and lemon juice and it didn't phase it. I do have ferric chloride at my disposal but afraid that to will eat the copper quickly. thanks.