# pocket holes into mdf?



## jhardesty82 (Apr 9, 2013)

I want to attach some oak 1 by 4s around a sheet of mdf for my outfeed table. I was wandering if anyone has tried using pocket screws into mdf.


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## asevereid (Apr 15, 2012)

You can absolutely do it, Kreg and others offer a coarse thread screw for that. 
Run a bead of glue and fasten like normal.


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## jschaben (Apr 1, 2010)

You _might_ be ok if you also use pilot holes in the MDF, otherwise the stuff likes to erupt around an unpiloted screw. Unlike wood, MDF is pretty dense and the material displaced by the screw has nowhere to go but up. That could push the edging away from the table.


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## Fred Hargis (Apr 28, 2012)

Be sure to put glue on it.....


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## johnnie52 (Feb 16, 2009)

MDF and screws and/0r glue DO NOT play well together!

MDF is pretty much just saw dust glued and pressed together. Any screw put in it that will have any force against it will tear a huge chunk out of the stuff. Glues just rips it apart when stress happens.

You can drill straight through MDF and screw it to something else. So what I would suggest for your edging would be to make a 1 inch of larger rabit in the edging, drill straight down into the edging and screw through the MDF and straight into the edging. Forego the glue except in the corners of the edging and use screws that do not go through the edging. I'd also use over sized (or fender) flat washers against the MDF at each screw.


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## jhardesty82 (Apr 9, 2013)

Ok, thanks. I thought it would be ok, but wasn't sure. Unfortunately I don't have enough long clamps to use biscuits, so I was hoping I could get away with using my kreg jig.


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## jhardesty82 (Apr 9, 2013)

I have had some success screwing mdf together when I built my router table. The edging on it is 1 by 1.5s though and I just glued it on.


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## cabinetman (Jul 5, 2007)

MDF is similar to particle board in that if screws are used properly they hold under low stress and low shear conditions. They work best if piloted, and coarse thread screws are used one time.

Both will take a direct glue application very well. Screws/pocket screws will create a local compromise in the substrates integrity. IOW, where the fastener is positioned presents itself as the area where failure happens. My preference would be to use just glue and pressure.








 








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## Wendel17 (Apr 20, 2009)

Even with pilot holes it'll split if you happen to tighten the screw a little too much. I like to use rabbets, glue and few brads to hold it untill the glue dries.


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## Manuka Jock (Jun 27, 2011)

johnnie52 said:


> mdf and screws and/0r glue do not play well together!
> 
> Mdf is pretty much just saw dust glued and pressed together. Any screw put in it that will have any force against it will tear a huge chunk out of the stuff. Glues just rips it apart when stress happens.
> 
> You can drill straight through mdf and screw it to something else. So what i would suggest for your edging would be to make a 1 inch of larger rabit in the edging, drill straight down into the edging and screw through the mdf and straight into the edging. Forego the glue except in the corners of the edging and use screws that do not go through the edging. I'd also use over sized (or fender) flat washers against the mdf at each screw.


+1 

Pocket holes into MDF ? 

Chase up the hardware designed for use with MDF , save yourself the grief


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