Screwing MDF

[Rob Morley]

I've found that can cause a small bulge where the screw goes through the dado which pushes the joint apart slightly.

[Mike Barnes]

I don't understand where a dado comes into the picture. Did I miss something? Just curious.

[Weatherlawyer]

I thought -all the way through this thread, that you were talking about putting screws near the end of the face of the MDF.

(You need to pilot drill and countersink screwing through the face of that stuff. And you need to keep as far from the edge as possible. 3 inches is getting close.)

MDF is a medium density fibre. That means laminations that are not even tightly bonded. An example of well bonded fibre board is Formica.

OK that is a different medium entirely. I doubt though that you would get screws into the end "grain" of higher density fibe board.

What you need to do is put some architrave or 2x1 on the uprights where the shelves are going to sit. Remember when measuring out for them that you need to keep them the thickness of the shelf down.

You want a 10 inch space from the top of the bottom shelf to the bottom of the next shelf up for books that are 8 inches high. So with a 3/4 inch board as the shelf the batton needs to be 10 3/4 inches from the top of the batton for the next shelf up.

(Another point to note is that shelves over 2 feet long need either extra thickness board or some other sort of extra support. A nice edging strip will act as a feature and help keep dust out of the shelf below.)

[Rob Morley]

Plan 'B' above :-)