I've been pulling the carpet up and getting the nails out from where the carpet tack strips were nailed to original wood flooring, but about a half dozen are now headless. I watched several tutorials on how to get them out, but one of the nails broke and is now flush with the floor. The internet says to use a nail setter to punch the hole in and then fill it up. I bought a set and tried that, but the nail would not budge at ALL. I hit the nail setter as hard as I could. Any thoughts?
I've had this problem when working on hardwood before, my solutions was to
If you use an grinding wheel (but an angle grinder or file should also work) to smooth out the rough surface of the nail, and keep an eye on the area while refinishing the floors.
Your first pass with 60 grit sandpaper shouldn't cause the paper to tear. If any nails are sticking out after that pass try to drive them flush or re-grind/file them before your next pass.
You hit it as hard as you were willing to while swinging a hammer at your other hand.
Try: tap... tap... tap... BANG.
The 'taps' do nothing except gear in your muscle memory and let you know if it will slip when you go 'bang'.
I bet the flooring sounds funny when you hit it. The wood is probably bouncing which is working against you, so you have to hit it twice as hard as you want to.
If you just can't get it to go, remember these spots and go over them with sacrificial paper, either all at once, or just before you change paper. Steel isn't really that hard; they'll sand. If you have an edger or a ROS use that instead of having to change paper on a drum.