MDF and Particleboard Gardner MA
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MDF and Particleboard
MDF and Particleboard
How two versatile woods can be both a blessing and a curse.
by Karen Nakamura
Cheap, plain and definitely not wood. That’s how many woodworkers describe particleboard and MDF (medium-density fiberboard), but think these words instead: inexpensive, uniform and stable.
• Inexpensive. MDF and particleboard panels run $25 to $35 a sheet (oversized at 49 in. by 97 in. so you can cut off a dinged edge).
• Uniform. Collectively called composite wood, MDF and particleboard panels don’t have the irregularities of veneer-core plywood, such as voids on the inside and patches on the outside.
• Stable. Composite wood doesn’t shrink and swell across the grain or warp to the same degree as solid wood.
Composite wood has a few significant drawbacks: it’s heavy, easily damaged and not very stiff. In addition, it doesn’t hold screws as well as solid wood, swells when it gets wet and creates clouds of obnoxious sawdust. Particleboard is fine for utilitarian work, but MDF is preferred for furniture projects. MDF is smoother, takes better detail, holds screws better and paints very well once its edges are sealed. Whichever one you choose, use only carbide cutters, because the binders in the wood are very abrasive. Even carbide will wear more quickly than normal. Here we’ll only cover the basics, but a wealth of free technical information on different grades of composite wood is available from The Composite Wood Council. You can download entire pamphlets at www.pbmdf.com or call (301) 670-0604.
MDF takes a much crisper edge than particleboard. MDF is made of very small wood fibers, almost like flour, while particleboard is made from larger, coarser fibers. Particleboard has a tendency to chip out when routed. If you want sharply defined edges with particleboard, glue on a solid wood strip.
Man, this stuff is heavy! Projects made from MDF and particleboard can weigh a ton. A full sheet of 3/4-in. MDF is 97 lbs. A sheet of particleboard typically weighs 85 lbs. A sheet of veneer-core birch plywood, by comparison, comes in at 60 lbs. Extra weight means joints in moveable furniture have to be extra strong.
MDF and particleboard are extremely flat. They’re perfect for veneering because there are no lumps or ripples to show through extra-thin sheets of veneer. Glue veneer on both sides to keep the panel from distorting.
It may be flat, but it’s not stiff. Look familiar? MDF and particleboard shelves are notorious for drooping, even from their own weight, unless they have additional support. Shelves that are 10-in. deep should be no more than 24-in. long.
MDF’s thickness is usually right on the money. Unlike plywood, which is generally undersized, MDF and particleboard often fit right into standard-sized grooves.