Quote: Originally Posted by
fatejd 
How are you connecting the mirror clips? The screws on Lowes' website look a bit long to work and I've had bad luck trying to use screws in MDF.
Two tricks to using screws in MDF:
- use sheet metal screws, which have no taper like wood screws do.
- drill the holes for them to be slightly larger than the shank of the screws, so only the threads are doing any work. You don't want to displace the MDF with the shank of the fastener. Drill almost as deep as the screw will go, so only the very tip is getting into undrilled MDF.
If there's much load on the fasteners, use screws as long as possible; for instance, if you're using 3/4 MDF, use 3/4 screws, because whatever you're fastening will take up some of the length.
If the load on the fasteners is light, you can use shorter screws, just long enough for a firm hold.