What is the finish on a 642?

[Rule3]

I was looking at one at the shop and it appears to have some kind of "corrosion" or something ate into the finish. I have a 642 myself and it seems to have a type of clear coat or some such finish over the alloy.

Anyone know what exactly the finish is? I just wondered how the gun at the shop could have gotten that way??

 

[bountyhunter]

It could have gotten that way if somebody cleaned it with Gunscrubber or brake cleaner or similar solvent which would trash the clearcoat finish into major ugliness...... and then, out of embarrassment, he stripped the rest of the clear off leaving the metal at the mercy of the elements.

I have never seen a listing of the exact material used for the clearcoat, I assume it is some kind of urethane or derivative.