# I just build a MDF table and its bending. How to reinforce?



## de-nagorg (Feb 23, 2014)

A picture of the underneath would be a great help.

Maybe a 1 inch square tube framework welded in a rectangle and "screw it to it" underneath will strengthen this.



ED


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## Dritan (Mar 9, 2016)

Thanks ED. Will post a pic underneath today. Thanks


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## SeniorSitizen (Sep 10, 2012)

A couple of miniature trusses with a slight camber might solve that problem.


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## Dritan (Mar 9, 2016)

Thanks bud


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## joecaption (Nov 30, 2011)

There should have been a frame made first using a Kreg tool and wooden gussets in the inside corners to mount the legs to.
MDF was not a great choice for a table top.
https://www.google.com/search?q=bui...sAQIHA&biw=1366&bih=657#imgrc=ja_a_wQyytWYtM:


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## Dritan (Mar 9, 2016)

Well yeah you are right i guess, but i was on a budget and i had the steel legs and left over MDF. Now what if i do just the wooden box?


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## Dritan (Mar 9, 2016)

Dritan said:


> Hello i just bulit a 180cm by 90 MDF table. Its bending i would like to reinforce.


This is the view from underneath.


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## ZZZZZ (Oct 1, 2014)

Where/how is it bending?

Furthering what Joe said, you could take off the legs and glue a gusset or just a square piece of 3/4" plywood to the bottom corners. then remount the legs into the plywood. Though of course this would raise the table height 3/4".


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## Dritan (Mar 9, 2016)

Its bending right in the middle. Where you would sit. For now its fine bur in a month i dont know.


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## ZZZZZ (Oct 1, 2014)

How thick is the MDF?

You could glue a "mini-beam" across the underside where it is bending to support it.


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## Dritan (Mar 9, 2016)

MDF is 1.8 cm and that is a great idea


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## ZZZZZ (Oct 1, 2014)

I'd use some construction adhesive (such as Liquid Nails), regular wood glue won't stick to the MDF lamination. Turn the table upside down, glue it in place, put some heavy weights on it, let it sit for a good 24 hours.


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## Dritan (Mar 9, 2016)

Thanks zzzzz great answear.


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## Oso954 (Jun 23, 2012)

I have always used 2 anti sag stiffeners, when needed (the mini beam idea). I generally set them rightly evenly spaced, or about 1/3 of the width in from each edge.


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## Dritan (Mar 9, 2016)

Oso954 said:


> I have always used 2 anti sag stiffeners, when needed (the mini beam idea). I generally set them rightly evenly spaced, or about 1/3 of the width in from each edge.



i hope i find those in Albania. The only way is to screw them in right_


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## Oso954 (Jun 23, 2012)

I prefer to use wood and typically glue them vs using the sheet metal ones they sell. 
With a 1.8 cm top, you are really limited on screw length to develop strength.

I would use wood. I might use screws (thru stiffener and into mdf) to hold the wood in place and provide clamping force while the glue is drying vs weighting them down. While I wouldn't remove the screws, I would not really be counting on them for any significant strength The glue is where the strength is.

Here is a pic of a 72 inch (about 183cm) table with wood stiffeners. They are closer to the edge to allow for the folding legs. If you mount them a bit further away from the edge, they will not be as visible.


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## ChuckF. (Aug 25, 2013)

This will continue to sag, it's one of the problems with MDF.

ZZZZZ has the best answer, a rectangle of 3/4" plywood inset to the underside, lots of glue and the legs remounted onto it. It means the table gets 3/4" higher. Try to get some decent quality plywood, like maybe birch.

Looks nice though.


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## Msradell (Sep 1, 2011)

ChuckF. said:


> This will continue to sag, it's one of the problems with MDF.
> 
> ZZZZZ has the best answer, a rectangle of 3/4" plywood inset to the underside, lots of glue and the legs remounted onto it. It means the table gets 3/4" higher. Try to get some decent quality plywood, like maybe birch.
> 
> Looks nice though.


 I certainly agree with the plywood but using birch plywood would be a waste of money. Birch plywood is no stronger than other plywoods, it just looks prettier and it's easier to stain. Plywood with more plies would be stronger but it certainly doesn't need to be pretty.


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## Bob Sanders (Nov 10, 2013)

MDF is not good for that. Use a few stiffening ribs on the underside and move the legs a little further in away from the corners. I would put them at least 10 inches in from the corners.


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## clawlan (Nov 29, 2015)

How about screwing a unistrut or similar metal beam onto the underside?


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## Dritan (Mar 9, 2016)

One of the most appreciated ideas, these are great solution i belive, they are channels for piperings very strong.


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## ddawg16 (Aug 15, 2011)

MDF is good for a lot of things....but is NOT stiff. It needs a lot of support. It's a great material for things like Router tables and Radial Arm saw tables.....BUT....it has a lot of support underneath. 

Unistrut is a good option. They make two different sizes. Don't use the 1" stuff, too shallow. If it was me, I'd be also attaching a strip of angle to the back side for added stiffness.

One of the issues you are going to run into is screw retention. MDF does a pi$$ poor job of holding screws.

If your table does not work out as expected, consider getting a butcher block slab from Ikea....pretty cost effective.


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## mske390 (Feb 24, 2015)

2x4 box frame with cross beams will stop the sag, simple and cheap


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## jlhaslip (Dec 31, 2009)

Angle iron or square tubing screwed/glued underneath.


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