Some gutsy stories out there...so its not just me, and my thought that RV building & modifying is sometimes a tough sport is true after all!
We've had drilling through the fingerprint and drilling through the nail; I'll meet ya in the middle. Drilling the holes in the baffle left inlet ramp lower-outer corner. Clecos in, but holding the material together for security and line-up, fingers on top pointed down, drill bit going up...right between the nail and the finger, parallel to the nail bed. Three laps of the hangar, speaking jibberish because my sons were there, and couldn't scream what I wanted to! Shop towel and masking tape bandaid, and press on! Made a cool tunnel that took a while to heal.
I've also discovered that timing is everything when removing side-grip clecos. Keep the free hand clear until the cleco is off the material and fully closed! Don't go for the grab early! That one may have hurt more than the drill, but didn't bleed.
I think it was Paul Dye that told me to try not to bleed on the plane, but that the plane isn't truly yours till you bleed on it. By that metric, though I bought mine, its truly mine!
Cheers,
Bob
(Trying not to bleed on it, one day at a time!)