Is 3/4" MDF strong enoguh to hold a 27" TV? (1 Viewer)

[tom_furman]

My gf wants a flexy-rack for her tv/dvd...i'm not sure if a piece of standard 3/4" MDF will be strong enough....i think the tv might make it sag in the middle.

if so, what other materials can i use?

 

[Seth_L]

I don't think it will be. MDF sags noticably from it's own weight in only a few weeks.

I'd try a good 7 layer plywood with some reinforcement underneath.

Seth

 

[tom_furman]

what sort of reinforcement?

 

[Dustin B]

I built a desk out of MDF. I'm not sure if the laminate helps any. But the desk is L shaped. One half longer and narrower (2' x 6'), the other half shorter and wider (4'x3'). Those dimensions are rough guesses, I can't measure it right now. On the underside of the out side edge, all the way around (about 4" deep) we doubled the MDF up to 1.5" thick. Then 4 or 5 places around the desk we made it 1.5" thick across the desk. There are draws for legs at either end, and a folding leg in the middle.

I can stand on it (I weigh almost 200lbs).

 

[Ron-P]

Tom,
Here is a pic of the flexy I built. It holds my 46" Mits 16:9 and all my components.

I used 6-3/4" all-thread rods, 2 of which are at the center of the flexy and 3/4" MDF. It is still in the unfinished stage but I have had it up for over 3 months with no sagging problems at all and it is very solid.
I'm working on removable side panels right now and still need to finish dressing-up the all-thread.
Peace Out~

 

[Darren_T]

I never use MDF for any span longer than 2' unsupported. A good way to support it is to apply a hardwood or even MDF edge band to the front and back of the shelf of about 2" tall. This will add rigidity but will probably still sag under the weight of a 27" television. You could put a central support in your rack similar to what Ron-P did which looks to be a cosmetically superior way to achieve the stability necessary.

Darren

 

[Dan Hine]

I made a 48" long flexy rack and had a 27" tv on it. There was a very slight sag to it but barely noticable. Also, I only used 4 rods on each corner. I would wager that a middle support would have removed the sag completely.


Dan Hine

 

[tom_furman]

thanks for the help so far guys! i definetly see the need for some sort of support in the middle.


where would i put the support in the middle so that the top washer/nut would not hit the tv?

 

[Chris Tsutsui]

If you can distribute the Televisions weight so that it's towards the edges of the MDF platform the MDF sheet won't sag as much.

I use thin pieces of Cedar because I like the smell and it's supposed to repel bugs and resist mildew.

Just an idea...

 

[Ron-P]

where would i put the support in the middle so that the top washer/nut would not hit the tv?

I did not put top nuts or washers on the 2 center supports for that exact reason. The top of the all-thread rod matches the top of the shelf. There is a nut and washer on the underside for the needed support. I do have top/bottom nuts on the center supports for the other 2 shelves for locking it all together.
Peace Out~

 

[tom_furman]

ok..i understand that. how did you get the middle rods to be shorter than the others?

the middle posts have to be cut down so that they dont stick out correct?

 

[Ron-P]

Yup. Wrapped them up in a towel (to protect the threads), stuck them in the vice, grabbed my hack-saw and cut away. I then threw them on the buffer and cleaned the ends up. Worked perfectly.
Peace Out~

 

[Mark Fitzsimmons]

Why are they called flexy racks?

 

[Chris Tsutsui]

Maybe because they are adjustable (flexible) moving the shelves up and down on the "turnbuckle" like rods.

After time the panels sag (flex) and can be flipped as a fix. Join the "Semi-annual flexy flippers"

 

[Dustin B]

A towel works well Ron? I've always just put a couple nuts on the rod and then stuck it in the vice.

 

[Ron-P]

Fine Dustin. Go ahead and show up my towel idea with something easier
Peace Out~

 

[Dustin B]

Always glad to be of assistance Ron :p)

 

[Chad Anson]

Here's a trick to cut the allthread rod -- screw the nut on and then cut it. Then, unscrewing the nut will help to repair any (minor) damage that you may have inflicted onto the threads by a wayward hacksaw stroke.