How to Keep a Fastener From Tearing Out of MDF
Medium density fiberboard (MDF) is a plywood substitute made of a mixture of wood chips and glue. Like plywood, it comes in 4-by-8-foot sheets and can be sawed, glued, nailed and screwed. Its flat surfaces accept paint well, and cabinet-makers often use it for the construction of interior cabinets and fixtures. Although you can screw and nail MDF, both fasteners frequently fail as the material chips around them, especially if you drive them into edges. To prevent fasteners from tearing out of MDF, you have to take precautions when you drive them.
Glue MDF joints before you nail or screw them, whenever possible. Spread a bead of carpenter's glue along the edges to be fastened, screwed or nailed, then wipe away the excess glue with a damp cloth.
Drill a pilot hole and countersink before you screw MDF. Use a pilot bit one or two sizes smaller than the shank of the screw to drill a hole the length of the screw, then drill a small indentation with a bit the same size as the head of the screw. Drive the screw into the hole and sink the head fully into the indentation.
Drive screws with a drill rather than using a screwdriver. When you use a screwdriver, the screw can wobble when you are driving it. This will chip material from around the hole and make the screw less secure.
Drive nails or staples with an air-powered nail gun whenever possible. The gun will drive the fastener securely in one motion, creating less possibility for chipping than if you use a hammer. If you must hammer nails into MDF, use ring-shank nails.
Keep anything made from MDF dry. Moisture makes the fibers in the material separate, undermining the ability of anything, including glue, to hold it together.
Prevent screw heads from tearing into the surface of MDF by using washers. This is especially important if you have to drive the screw closer than 1/2 inch to the edge. Drill a pilot hole, insert the screw through the washer, then drive it into the hole with a drill.
Things You Will Need
- Carpenter's glue
- Damp cloth
- Assortment of drill bits
- #2 Phillips bit
- Nail gun
- Ring shank nails
- Fill countersink holes and nail holes with epoxy wood filler, then sand the filler when it dries. The epoxy will help keep the fastener in place and will disappear when you paint over it.
- When you drive a fastener in to the edge of an MDF board, make sure to drive it down the center. If it is too close to either face, material can chip away from that face and cause the fastener to fail.