Can a capo damage a guitar?

theslifelife,  I use a capo on my my expensive (for me anyways) guitars on stage almost every week and have been for over 14 years.  Never had a capo damage any of my guitars, and I've had a lot of different guitars.

Now, anything  could  ding and/or damage a guitar.  I could drop a quarter by accident on my guitar and if it landed just right, ding it.  Ha ha!  So, that argument is a bit weak.

I also use both the Kyser and Dunlop style capos.  One is handle "above" the neck, the other is handle "below" the neck.  Started off loving the Kysers all the way, but am now loving both equally for different reasons.

theslifelife, have to be pretty careless to do any damage- no matter what you use or don't use- I use a Keyser, very carefully-

Yes.  I think you're right.  If the tool was left on the guitar for a very long time, I think it would possibly be  capoble  of leaving an imprint as well.   

capo never contact frets, so no wear can occur. If yours does, you are ding it wrong

Sorry for book, but bit of an explanation here:

Garland,  Well, a capo will  contribute  to the wear, as will many things, in that it's causing the strings to be pressed down onto the fret, but I have not seen in my life time that they  accelerate  the wear.

The greatest contributor to accelerating wear that I have experienced (I stress that *I* have experienced, cuz I have not experienced everything) is gorilla gripping.  And with gorilla gripping, it will accelerate wear more specifically on the fret wire at the frets at the string number positions one most commonly uses cuz of the chords one most commonly uses.

Like for instance, with my guitars, the first signs of fret wear always happen on the 2nd and 3rd frets at the 1st to 4th string positions.  That's because the D chord, and all it's variations, is one of the chords I "play" around with the most.  By that I mean do the most run downs, run ups, hammer ons, pull offs, stretches to the 5th and etc.  Don't know why that is, but, as the kids say, it is what it is.  lol.

My point being that many things contribute to wear, but accelerated wear is caused by person specific things.   Now, let me also say that if a Capo actually did cause accelerated wear, I'd be in big, big trouble cuz I use a capo a LOT.  Every single week, almost every single time I play in fact.  So, again, if capos actually did cause accelerated wear, I'd be in BIG doodoo as the say.  LOL! 

Thankfully, I have not seen this to be the case with me.  I will admit to the fact that there is the possibility that someone could be doing something wherein the capo is actually causing some accelerated wear;  I just, at this moment, can't think what that would be.

Garland, Another thing that just occurred to me is that the reason frets will most likely wear more on places where your fingers are pressing the string down vs the other strings that the capo is holding down, is that,  generally speaking, whatever strings you're fretting with your fingers are probably, or most of the time, going to be the strings you're focused on playing with your right hand as well.

So, the pressure  and  the vibration coupled with your fingers causing a slight "grinding" effect from their slight movements will all contribute more factors to the wear of a fret at a specific spot than a capo simply fretting a string that may not even be plucked to vibrate will.

When you really break it down, there's so many things going on when one plays a guitar that put pressure and stresses on every part of the guitar (hard strumming, how one puts a strap on, gripping, percussive techniques, arm length and positions, and the list goes on and on!) that one could probably fill a whole book talking about it all.  lol.