Lightweight MDF for Desks or Tables

With MDF, weight is related to strength and durability. November 10, 2006

I've been commissioned to build a large desk that will require me to order three sheets of 3/4" x 4 x 10 MDF, veneered both faces with walnut. This material will be used to construct the top, drawer fronts, and casework. Is there any reason why I should not order the core to be lightweight MDF? I would like to minimize the weight of this thing without compromising its strength.

Forum Responses
(Cabinetmaking Forum)
From Professor Gene Wengert, Sawing and Drying Forum technical advisor:
There is a direct relationship between density and strength. For a desk, you might want a material that can be sat on, danced on, etc, and a material that will not compress or dent if impacted. Hence, the top certainly would benefit from typical MDF density. The sides could be lightweight if they are decorative and not structural.

From contributor D:
I used it on a few paint grade jobs in the past and found it tears out much more easily than regular MDF. What I mean is, if you make end panels for base cabinets and you slide them sideways on the subfloor and catch a seam, it will tear a chunk off the side of the cabinet. I have never had that happen with any other substrate. Also, if you make shelves with it, they will sag easier than normal MDF or ply. It certainly is lighter, but like Doc says, don't use it where you need to have dent and cup resistance.

From contributor J:
Fixings in lightweight MDF can rip out rather easily, and yes, sagging is a problem on large surfaces. We used it on large tables for a while to make them easier to lift, but the fittings kept getting pulled out and the tables sagged.