I've read some excellent ideas that have been written in these journals about this subject. Here's my two cents worth.

Coin Chemistry is a great book and should be in everyone's library. Keeping your coins that didn't make it is also a very good idea. I wish I had kept all of my coins that were BB'd. I would have a very nice collection of tampered coins by now.

I have about 150+ coins that have been slabbed and I would guesstimate that I've had about 10 to 15% of the total coins that I have submitted come back ungradeable. The large majority of those having been cleaned in some manner. I had two that were BB'd on my last submission. But I'm learning.

Reading is fundamental and I strongly recommend that you read everything that you can on the subject but experience is still the best teacher. Keep the coins that you've had BB'd for something to study at home. Go to coin dealers and shows and peruse through their inventories and try to find every coin that you can that has been cleaned. Don't buy anything...just look and learn. (I know that's easier said than done:)) Questioning the seller/dealer at these places or events is always a good idea. Many dealers have got much more knowledge and experience than most of us and are willing to share that information fairly readily. You can learn from his observations and experience and besides, it's also a good way to find out how honest he or she really is. If you ask him about a coin that you know has been cleaned and he hands you a line of B.S. then you know to move on to the greener pastures at the next table. When you are ready to buy, go by this one saying. "When in doubt..Throw it out" If you even THINK that it MIGHT have been tampered with in some way, pass it up and move on to something else. That goes for any venue in which you use to acquire your coins from your local dealer to Ebay or any other way that you can think of.

Mike

This is one my most recent failures. It's a 1920-S Standing Liberty Quarter that was improperly cleaned.

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