Pocket Holes & MDF

[Carroll Courtney]

Will pocket holes work on MDF?I will be making a 36"X36" cabinet paint grade and not much money in my friends budget.So I was going to purchase 1/2 mdf and make a frame and panel for the sides and solid for the bottom with 4" toe kick.But,going to double up on the 1/2 and make it a full 1" thick.If this won't work then will try and fit a sheet of birch plywood w/poplar edges into the budget.Just wondering Carroll

[Jim Becker]

The glue is essential for this method and you may get a serviceable joint, but honestly, the nature of the pocket hole screw is not ideal for MDF. I would only use it to help streamline initial assembly and then put glue blocks inside the jointer to reinforce things.

If you double up the 1/2" creatively, you can effectively create the rabbits that provide a much stronger glue joint opportunity and just use predrilled and countersunk sheet metal screws or 15 gage finish nails to provide some mechanical support. For some places, glue blocks will still be a good idea, IMHO.

[matt dumney]

I have Kreg system and I've used it on MDF. I found the kreg screws are lousy and used something with more bite. Definately use a good glue.

[J. Z. Guest]

I'd rather go with plywood. MDF isn't really all that cheap. MDF is damned heavy too.

[Larry Richardson]

I agree with Jeremy - Especially since it is a 1 sheet deal. I'd think the 1 sheet of 3/4 ply is less or equal to the cost of 2 1/2" MDF, and a lot less work. Where I am at a sheet of Birch "cab grade" is around $40.

[William Nimmo]

you can't give me mdf for free
never ever ever use it

[Brian Dormer]

Pocket screw joinery will work in MDF - but the critical element is designing and building the piece such that the joints will not be able to move. During construction - you have to clamp EVERYTHING and really plan out the process so you don't flex the joint. Once everything is together - the joints will hold. If, however, there ever is any flex, the MDF will blow out around the screws and the joint will fail. Real wood will take a little bit of flex but MDF is very unforgiving in this regard.