What is MDF? Plus Tips for Using MDF

Do's and Don'ts of using MDF

MDF (medium-density fiberboard) is inexpensive, durable, and a good choice for many woodworking and carpentry projects. Learn how to use it correctly, and how to avoid common mistakes.

By the DIY experts of The Family Handyman Magazine

Overview

Medium-density fiberboard is the most versatile building material I know of. Because it’s inexpensive and fairly durable, it’s a good choice for practical projects like shelving and storage cabinets. But MDF is great for decorative projects too. The smooth surface is perfect for painting, and a router leaves crisp profiles with no splintering, burning or tear-out.

Over the past 15 years, I’ve used MDF to build everything from crude shelving in my shop to fancy trim in upscale homes. I’ve even used it for furniture and ornate millwork like the trim board shown in the lead photo. In fact, my own home is entirely trimmed out with MDF moldings made from about 50 sheets of MDF. Yes, I’m a fan of the stuff. This article will cover the most important things I’ve learned about working with MDF—and help you avoid some of the frustrating mistakes I’ve made.

MDF is basically sawdust and glue, fused together under pressure and heat. It varies in color from tan to chocolate brown. Common thicknesses range from 1/4 in. to 1 in., but most home centers carry only 1/2-in. and 3/4-in. Full sheets are oversized by 1 in., so a “4 x 8” sheet is actually 49 x 97 in. A full sheet of 3/4-in. MDF costs about $30 (as of 2010). Some home centers also carry MDF boards in various lengths and widths. Working with MDF is no different from working with wood or plywood; you use the same tools to cut and shape it.

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Make your own trim—cheap!

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Combine MDF with wood moldings

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Prepare for a dust storm

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Don't drive without drilling

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Avoid full sheets

I blame my hernia on MDF. A full sheet of 3/4-in. MDF weighs about 100 lbs., and I’ve lugged lots of them from my pickup to my shop. But there are ways to avoid hernia surgery:

  • Buy half (4 x 4-ft.) or quarter (2 x 4- ft.) sheets instead of full sheets.
  • Some lumberyards and home centers sell MDF shelving, usually in 1 x 8-ft. sections. I like to slice these long, easy-to-handle shelves into trim stock.
  • Some home centers and lumberyards will cut full sheets into manageable sections at no extra charge.

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Sand, prime, sand...

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Don't drop it

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Don't let it get wet

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Reinforce MDF shelves

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Don't use a hammer

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Required Tools for this Project

Have the necessary tools for this DIY project lined up before you start—you’ll save time and frustration.

  • Miter saw
  • Air compressor
  • Air hose
  • Brad nail gun
  • Cordless drill
  • Circular saw
  • Countersink drill bit
  • Dust mask
  • Orbital sander
  • Paint roller
  • Paint tray
  • Router
  • Safety glasses
  • Paintbrush
  • Wood glue

Required Materials for this Project

Avoid last-minute shopping trips by having all your materials ready ahead of time. Here's a list.

  • MDF
  • 100 grit sandpaper
  • Solvent-based primer
  • Sanding pad
  • Wood glue