# Pocket hole through MDF to Poplar



## BinghamtonEd (Nov 30, 2011)

One of my upcoming projects is going to be a headboard for our daughter's new room. Nothing fancy, just two posts made of poplar, with a MDF panel between them with some curves routed on. Painted white. Probably will end up covered in stickers and crayon.

First off, let's get this out of the way :
"MDF." 
Boos and hisses

Now that we've done that…

Plan is to have mortises in the poplar posts for the MDF panel to fit into. Since this will be a fairly large panel, I will have plenty of joining surface. I plan on drilling pocket holes in the back of the MDF panel. Put some glue in the post's mortise, slip the panel into the mortise, and drive some pocket screws in to pull everything tight.

To me, this seems like it will work just fine, as the screws are going into poplar and not MDF. Am I mistaken here? Also, will regular TiteBond give any good adhesion between the poplar and MDF?

Thanks guys!


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## wapakfred (Jul 29, 2011)

Though I've not tried it, I think what you want to do will work fine…the screws will just be acting as the clamps until the glue dries (and Titebond will work just fine as well). The only risk would be the screws pulling through the MDF, have the pieces closely mated when you tighten them down, once the glue dries it won't matter.


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## dbhost (Jul 20, 2009)

I would seriously consider a different material, or a different construction method. In my experience screws and MDF do not get along all that well.


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## mnguy (Feb 4, 2009)

If Fred and I understand your plan correctly, the screws are really holding until the glue sets. I think you'll be fine, but I would use the washer head pocket hole screws and use a light touch/low clutch setting when driving the screws. I think it would be pretty easy to drive the screw right through the pocket in the MDF.

I also agree that regular yellow glue will work fine. But, you need to size the motise and tenons to hold the joint together; you can't rely on the pocket screws to reinforce it much, for the reasons above (pull through).


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## bondogaposis (Dec 18, 2011)

How thick is the MDF? I think it will work but will only be as strong as the MDF, which is not very. Don't plan on this being an heirloom.


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## JAAune (Jan 22, 2012)

That technique will work fine as long as you don't over-torque the screws. I'd recommend spreading the glue, applying a few clamps to pull everything tight then driving all the screws. Place the screws a maximum of 6 inches apart. The clamps can come off as soon as the last screw is in.

I'm guessing you want to use the screws as clamps because you don't have long enough clamps to do the job. That's fine but it's not as fool-proof as clamping first so you'll just have to be more careful and you'll want to use more screws.

Washer head screws will work best since they'll deform the MDF the least.

I'd recommend soaking multiple applications of either epoxy or polyurethane into the edges of the MDF after the glue up to solidify them. That will prevent crumbling or flaking on the edges. Sanding comes next followed by primer and paint.


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## 111 (Sep 2, 2013)

I would skip the pocket screws and just toe nail the mdf into the poplar with some pins.


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## Dal300 (Aug 4, 2011)

The MDF will work, but in my (not worth much), opinion, the top and bottom edges of the MDF will be subject to a lot of wear, tear and damage. It would be much stronger if you cut a dado into the posts and using a top and bottom rail with dados also cut in. You could cut through mortices and use the top and bottom rail as the tenons.


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## renners (Apr 9, 2010)

Put a tongue on the mdf and a groove in the posts, and use plenty of glue. I don't think the pocket screws will add much strength to the construction. In my experience, the threads tend to strip poplar easily. If you are going to go this route, use longer pocket hole screws with a coarse thread.


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## CharlesA (Jun 24, 2013)

Haven't done it in a while, but if you have the clutch set right on your driver and you use the coarse screws, pocket holes in MDF work just fine. I built an electric piano stand 12 years ago with that method, and still is very stable.


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## dawsonbob (Aug 5, 2013)

Just out of curiosity, how much more expensive would it be to use plywood instead of MDF? In this situation it would seem to me that cheap plywood would be a better choice. I'm a newbie, so I may be way off base.


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## Dal300 (Aug 4, 2011)

*CharlesA*, I just can't resist….... Why do you have to plug the piano stand in?

I should hate myself!


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## changeoffocus (Dec 21, 2013)

I think "Dallas"s idea is very good advice. I've not had that good of luck with MDF or particle board in a structural position. His idea makes the MDF in fill and somewhat of web as I understand your project. 
Enjoy your project.


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## Vincent (Mar 10, 2009)

If you can lay your hands on MDO (medium density overlay) use that. Since you are planning to paint, MDO take paint nicely and it will hold a screw better.


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## 111 (Sep 2, 2013)

Why do you have to plug the piano stand in?

Better yet, why do you need a stand for your piano, don't they come with legs?


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## CharlesA (Jun 24, 2013)




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## Rxmpo (Feb 23, 2008)

Ed,

I actually built a bed exactly as you described. Little Girls's bed. I used poplar and MDF. The head board and foot board posts are 3-4, don't remember, pieces of poplar glued together with mortise and tenon joints for the stretchers. 4 individual stretchers, 2 on top and 2 on bottom. There is 3/4" space between them to allow for the MDF to fit right between them. I glued a stop block at the bottom of the bottom stretchers to hold it in place while glue dried.

I routed out V-groove lines in the MDF to make it look like wood panels and painted it white. I didn't use any screws for anything other than the bed brackets and it is sturdy as a rock. How this helps. I have the sketchup drawings I made if you want something to play around with for your design?

Good luck,
Mike


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## BinghamtonEd (Nov 30, 2011)

Thanks for all the great input guys, it certainly is nice to have a forum like this to toss ideas around on.

Mike, that's an absolutely beautiful bed, your daughter is lucky! It kinda got me thinking about a different approach, much closer to what you've done.

After thinking about it some more, I'm going to try and talk SWMBO into letting me put together a whole basic bed. We currently have the metal frame, box spring, and mattress, and I think I can convince her that it will be far to high for our daughter, who is about 2 feet tall (tiny girl).

I'm thinking 2 6" tall rails with the surface mount Rockler hardware, cleats and slats for the mattress to sit right on. Headboard will be a simple 2 post design with the lower 6" tall horizontal rail and a thinner upper one as well. Then, I can make the panel piece of the headboard to the shape I want and fasten it to the rails from behind. Lower headboard rail would probably just be tenoned into the posts, even though the weight will be on the side rails, the mortise/tenon will probably outlast pocket screws and provide more shear strength.

My rationale here is that my wife is pregnant with our 2nd, a boy, and when it's time to move the boy to a bed, he can get this one with a replacement less-girly headboard, the rest of the bed stays the same. My daughter will be older enough for a larger bed at that time (my wife wants her to end up with a trundle bed.)

I'm thinking poplar for everything. At $3 bd/ft I should be able to do this for under $100 with hardware and paint.

P.S. To clarify, I am not looking for heirloom here. Just something that will last 3-4 years. If it's still good after that, we have plenty of friends who will probably be happy to take it off our hands at that point.


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