So I tried installing my new Samsung 55" inch LED above the fireplace on an articulating mount (about 45 pounds on the TV) and found metal studs. I decided to open up the wall and install 2x4 wood blocking between the metal stud that was centre in the fireplace and one that was 16" away on centre. I ended up installing 2 of the 2x4, one at the top of the mount and one at the bottom. I then repaired the drywall wall and attached the mount to the blocking with 6 1/4" lag bolts. This is my first time hanging a TV and I am probably being paranoid but just wanted to check with some more expierenced people to determine if this will be strong enough.