[mwertheim]

12 years ago we had a custom cabinet built into the alcove space in our new house. Back then the TV was a 4:3 Mitsubishi projection. Five years ago I bought a 50" Sony SXRD which barely fit into the space. Now I am getting that replaced under Sony's replacement program for these defective optical blocks with a 55" HX820.


So my problem is I have this huge hole in the cabinet and a 1.5" thick new TV coming. Given that it's now 55" it will sit just out side the hole and rest just barely on the two vertical columns on the left and right side of the opening. The cabinet itself was built into the alcove space and doesn't go all the way back to the drywall. It's about 2 inches short of the drywall. The walls of the cabinet are made of MDF and I doubt they would hold the weight of the TV (51 lbs). The other problem is that the distance from the outside edge to the back of the cabinet is just shy of 30".


Please help me figure out the best way to mount this new TV. I have seen a Videosecu mount that extends up to 31" which may work if I can figure out a way to secure the mount to the back of the cabinet but I'm open to other ideas. Thanks for the help!

 

[simpletwig]

Here's what I would attempt to do (depending on access to the mdf boards)

Idea 1:

Since mdf won't hold a screw well, you'll have to try to sandwich the mdf between solid 1x4's. I'm assuming the MDF is 3/4" thick. In order to sandwich solid wood, which will act as braces for a plywood new backing, you'll need to have access to the other sides of the MDF, those outside the original TV hole.


If you can do the above, positioning it full top to bottom and away from the face of the cabinet, then you can add 3/4" plywood to be flush. They plywood could be veneer that you paint black.


Be sure that the 1x4's go all the way to the floor, and that they bolt into each other (to create the sandwich) so that the friction between the 1x's and the MDF helps hold it in place. Each side will essentially support the 26 lbs.

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Idea 2:

If you can't attach the 1x4's, then maybe you'll have to create a plywood cube that fits exactly into the space, fastened directly to the MDF, again using friction to help hold it in place and prevent it from 'falling forward'. And again make sure you support the weight from the floor up.


With both solutions adding 3/4" veneer plywood attached securely to the above, also adding 2-2x3's studs to the back horizontally so the plywood doesn't bulge when weight is applied, and give you something to mount a bracket on.


Hope these couple of ideas help with your situation. It's hard to make suggestions when you can't see and feel the material yourself.


And if the MDF is smaller than 3/4" thick you have a real problem as it might just crack and give way. Also, I mean real plywood that's 3/4" thick and not MDF board. Good luck.

 

[mwertheim]

Thank you Simpletwig for your post. I can sort of do Idea #1. If you notice in the picture you can see an exposed 2x4 stud in the wall. I could drill through the back of the mdf cabinet and into the stud but there is a gap of probably 2 inches between the backside of the cabinet and the 2x4 in the wall. I could get 5" or 6" lag bolts and get deep enough into those studs, but I'm wondering how much the open space will weaken the hold of the lag bolt. I'd probably use 1x4 strips in the cabinet to do the front part of the 'sandwich'. Given the tv is only 52 lbs I'm thinking that might be enough???

 

[simpletwig]

You can't have any gaps as the weight of the TV will tear, crack, twist, etc. the MDF potentially. Like I mentioned you need to sandwich the MDF between solid wood.


I was also talking about the sides, not the rear of the cabinet... if you go from the rear you will be cantilevering out quite a bit to reach the TV, that means the weight of the TV isn't 52 lbs, but more like 65-70 lbs. The weight of the TV needs to go directly down to the floor. The cabinet could be used to do this if it is reinforced properly to not move, twist, crack, etc.


You can certainly connect whatever you build to hold the TV to the studs in back, to prevent the TV from wanting to fall forward.


Look at it this way, from the living space backwards:

TV fastens to>bracket fastens to>plywood that fills the entire hole which is prevented from warping with >full length strips of wood on its back (use screws), which are fastened to > side 1x4's sandwiching the MDF on the sides, which are> connected to each other, and to the studs in the back to hold everything in place and prevent warping, twisting or movement of any kind.

Further, below the opening are supports to safely bring the weight of the TV to the floor.


Why so much trouble? because your furniture is MDF and if it gets moisture due to humidity it can become weak, and your TV is expensive.