What are the main options for fastening MDF to MDF?

Question

I am interested in building boxes and cabinets from 3/4" MDF (I know, I could buy plywood. Bear with me.) What are the main types of screws and fasteners I can use to do this?

I am aware of

• glue
• serrated screws
• drywall screws
• confirmat screws
• pocket holes
• biscuit joints
• dowels

Please explain the pros and cons of each technique.

Answer 1

I've never tried it with MDF, but because you specifically mention the need to disassemble/reassemble it, you might want to look into using something like a T-nut aka tee nut or other types of threaded inserts, so you can attach that to the board, and not have to worry about the screws / bolts slowly wearing away the MDF.

Answer 2

It sounds like you are trying to build something in one place, pack it up and re-build it in another. If this is the case then screws are the way to go for dry fit, and then glue and screws for the final instal. I generally use Course thread dry-wall screws - because I feel they bite and pull MDF the best.

The only thing here is that there is a limited number of times that you can use the same holes with MDF, the Fiber-board looses a little meterial every time you screw into and out of it. So if you are building in a shop and then transporting onto site and reassembling once you are fine, if you are going to build and then rebuild this many times it will get less stable each time you do it.

As a side note, I also like to use pocket-hole jointery a lot because I like that it hides the screws from view.

Also, whenever I build boxes to be re-built I always make sure that I have some small square blocks with me. I use these blocks to make sure the inside of the box is square, just screw them in and it helps to keep the box from racking side to side.

Answer 3

For corner connections that are undoable I would recommend Cam Screws or Cam Bolts. These provide easy lock and unlock of connections. Cabinet connecting bolts.

(I am not affiliated with this store, just showing an example)

Typically, like in Ikea furniture, they should be combined with dowels and a panel across the back etc for rigidity. This will help the 'shaky after a while' issue.

Answer 4

Glue is going to work great for any porous material like MDF. You mention biscuit joints, which is really just an avenue for getting the glue in there. With the qualities of glues that are available these days, your joins will be the sturdiest part of the cabinet.