Low-Tech Cleaning Of Silver-Clad Kennedy

I picked up a 1966 Kennedy half at the bank today. The coin had some green, powdery surface crust that I believe was the first sign of corrosion. Except for the crust it appeared to be a decent AU example. Photos:



I tried a low-tech cleaning technique which I think was pretty successful. I poured a little white vinegar into a coffee mug and heated it in the microwave for 30 seconds. I put the coin in the hot vinegar, swirled it for a few seconds, and then rinsed it well with tap water. I gave it a final rinse with methyl alcohol (almost as good as acetone for removing water) and let it dry. The green crust is gone and the coin is now quite lustrous. I can't detect any signs of surface damage. Photos:




I don't know that I would use this method on an expensive coin, but it appears to have worked very well in this case. It might be worth a shot for low-value coins with light corrosion.