Why do strings corrode in picking area, not fretting area?

[blauserk]

I don't usually have too much of a problem with corrosion, but I went a looong time between changing strings recently so the corrosion was very noticeable with this change. And the thing that struck me was that corrosion was far far worse between the end of the fretboard and the bridge rather than in the fretboard area. That is, corrosion was worst where I normally pick (where I would think my skin would make less frequent contact), and fairly light where my skin is constantly making contact (where I'm fretting notes).

Or does this mean that my fingertips don't sweat that much, but the meat of my hand does? Or that my right hand makes much more than incidental string contact?

[pops1]

Or that the natural oils from your hand covered the strings on the board, where as the strings from the bridge to the board were exposed to elements with no protection. ??? I would guess you are getting oxidation as opposed to rust.

[Don Grieser]

Although BlueChip picks hardly wear, I find they discolor the wound strings in the area where I pick. Maybe it's that?

[Mark Gunter]

Too many variables for a quick, reasonable answer to this. But in my case, it's the same, there is far more discoloration and wear where the pick strikes than elsewhere.

Some of the variables would be 1) personal body chemistry, 2) type of pick, 3) type of strings, 4) playing style, 5) local climate. In my case, I often use coated strings, most people's strings will take the worst beating from pick strikes, second to wherever the strings contact the metal frets. With coated strings especially, the coating will wear away, then the windings will take a beating.

I guess I'm just not as surprised as you are about the results when considering the physics. But we've all heard from people who say their body chemistry destroys strings, presumably where their fingers touch them. That's not my experience. Maybe one such will chime in here. My assumption is that there are enough variables that my experience wouldn't equal everyone else's so I would never have thought to ask or comment on it.