Dave wrote:I have been using acetic acid for a couple of years, I found something better, faster, and safer, citric acid. Citric acid is a powder, I put @ hundred pennies in a plastic bottle, dump in a couple of oz. of citric acid fill the bottle with hot hot water. Shake the bottle for a minute or more. Dump the dirty water and rinse and they are clean.
Citric acid merely pulls off the top layer of copper and leaves behind a pinkish penny. From my experience it does not pull off the major gunk and or verdigris.
THIS IS NOT A CLEANING TECHNIQUE TO USE ON A COIN WITH ANY NUMISMATIC VALUE. PERIOD!!!!
~JobIII