How do I strengthen a plasterboard wall (with timber/plywood/mdf) by cutting and resealing like new?
I would fix a 6mm pad the size of the LCD fixing panel to the out side of the plasterboard which would be strong enough to take your TV. The plaster board is screw fixed to the metal studs with black partition screws which require no pre drilling they simply screw straight in to the steel with a battery drill, the black screws are not Pozi although similar, they have a special bit which you can buy from a builders merchants with the screws. Try to span both metal studs with the MDF and screw in to place. the MDF panel could also be glued on the back with gripfil No Nails or similar, then paint the MDF to match the wall colour then fix the metal mounting plate to the MDF using Pozi screws. This should be strong enough to support all but the largest of TV sets. If you are not able to span two of the metal studs as the LCD would not be in the optimum place try to centre the MDF on one stud and glue and screw into position this option would still give enough support PS if you cut the plast
