I’d like to mount an articulating arm for my 43” TV in my basement, however have metal studs unfortunately. The mount is made for a single stud install. Luckily I have access to the back side of the wall, and could work from there. Could I install a wood stud next to the metal stud and mount that way? Or would a large piece of plywood between the studs behind the drywall be a better approach with some toggle clamps holding it in place? I don’t really want plywood on the outside of the wall if possible. Thanks for the help!
There are two solutions, both of which you've outlined:
1) Brace two studs with 2x4s and mount the tv to that.
This is hit or miss -- stud spacing has to match the bracket spacing, and you need to open the wall up enough to add the new studs and ensure that they are stable and that the metal studs won't buckle.
2) Put a large piece of thick plywood across multiple studs and anchor to that. This allows you to have different spacing on your studs vs your bracket. It also creates a more rigid platform.
I elected to do #2 -- since the plywood is significantly smaller than the TV you can't see it anyway.
Not sure how you'd get the plywood behind the wall -- you could remove the sheetrock and replace it with plywood, but you probably need thicker plywood than the standard 1/2" sheetrock, so it will stick out anyway.