I'm in the market for one of these copper coins for my type set. Many are rated "details" and marked "corrosion". In spite of this non-grade these coins still are pricey at the VG-EF grade level and look pretty good compared to the non-corroded (as graded) coins. My question: is corrosion something I should be wary of as I would "cleaned"? Corrosion seems natural to me as it is a copper coin...which corrodes? It's certainly not "damaged"? or is it? I need perspective on this please.
Corrosion is damage to me. That or cleaning make it a problem coin. I own several. There is nothing wrong with it as long as the price is right and it has a nice look.
There are degrees corrosion. As you say, it's a natural process that largely depends on factors such as atmosphere and location. Some heavily corroded coins spent some time in the ground, others had hard lives battling the elements and chemicals from normal circulation. So in most occasions, corrosion is completely natural. Cleaning, however, is not natural but rather intentional alteration. Both, cleaning and corrosion, of course, will generally wind up in "details" holders, but eye appeal varies largely between coins. Some cleaned were dipped, others were scratched up with a brush, leaving hairlines all over the coins. Some corrosion is mild and only at the microscopic level, where other coins have the surface of an eggo waffle. I my experience, more people are forgiving of cleaned coins that were dipped. I think the idea behind that is there is a chance that the coin will eventually retone over time and get to an acceptable color. There is no going back on corrosion, unfortunately. However, I've seen many coins with porous surfaces, still have sharp, pleasing features, and I would have no problem adding those to my collection.
My personal opinion is you are better off with a nice pleasing lower grade problem free example, than a higher grade problem coin. Plus keep in mind just because a large cent is in a problem free holder does not mean it is problem free. Look closely at all of the coin. There are some very please VG or F coins that I really like.
Again i would say it is imo a personal choice, that is a nice coin but for sure has problems, light corrosion on the reverse at about 4 o'clock, and a strange spot of possibly corrosion at about 3 o'clock on obverse !!
