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Discussion Starter #1
Hey guys, I'm working on some shelves in MDF. I'm planning on pocket screwing the shelves to the sides and I'm looking for a jig/rig to make sure that each side is dead on from the bottom of the side.

I'm picturing setting up a story pole, or just pull tape from bottom of side. Once I have a mark for the top of the shelf i will clamp a square and pocket screw towards it.

I just dadoed my last set and it came out good but i wanted to try this technique also.

Any ideas for deadly accuracy?
 

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are talking like a 12" speed square? that sounds like a quick solution to me, but it'll be untertesing to here other ideas on here, these guys are really crafty. good luck
 

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Old School
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Hey guys, I'm working on some shelves in MDF. I'm planning on pocket screwing the shelves to the sides and I'm looking for a jig/rig to make sure that each side is dead on from the bottom of the side.

I'm picturing setting up a story pole, or just pull tape from bottom of side. Once I have a mark for the top of the shelf i will clamp a square and pocket screw towards it.

I just dadoed my last set and it came out good but i wanted to try this technique also.

Any ideas for deadly accuracy?

I can appreciate your sense of adventure, but IMO, pocket screws for shelves are a bad idea, and I wouldn't recommend it. In fact, I just don't like pocket screws, and don't use them.








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Really underground garage
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One technique would be to use...squared,fitted pcs of say 1/4 ply as deviders........but then,if you did that....why not just despense with the pocket screws and leave the deviders in?Just sayin.BW
 

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I agree w/ Cman and wouldn't use pocket holes that way either, I don't suppose they would be all that bad UNLESS you are talking about using JUST pocket holes without dados, in which case I'd say that's a bad idea. My understanding is that MDF (I haven't used any) doesn't take screws well.
 

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Just because Cman doesn't like them that's his prerogative and I can respect that but I use the crap out of pocket screws and think they work great. To me there is nothing like gluing something and leaving the clamp on.
However I would not use them on MDF. Dado is the Ideal situation for that material.
 

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Discussion Starter #7
Thanks for the replies. I was afraid you'd all say i was cheating... So i am going to cut the spacers and leave them in place on the outsides, fastened with brads and glue. If i don't come up with a good dadoing jig for my router I'll just screw the inner sides to the shelving as the two boxes will conceal the middle. More questions/introduction to follow!
 

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One technique would be to use...squared,fitted pcs of say 1/4 ply as deviders
That works like a champ as far as making sure the shelves line up square. I did that building some laying boxes for my hens that I needed level but would be removable for cleaning.

If the sides are dadoed the assembly should be right on the money anyway unless I am missing something. I haven't used pocket screw at all but that is because I have put off getting the kit.

I know they use special fasteners for MDF but I have built MANY speaker boxes with MDF and when glued/screwed I have yet to blow one apart even in a sealed enclosure. They are also silicone'd on the inside seams so I am not sure how much that influenced the durability of it. This is just using drywall screws. Pre drill is your friend on this. It may not be "the way" but it has worked for me many times.

Good luck with your project.

Scott
 

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Discussion Starter #10
The pocket screws are amazing. I'm sure you've been over this a few times here but for me, working with contractor tools in non shop space they are a major asset.
 

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Discussion Starter #13
these shelves will have a face frame and backing to help support the mdf also. should be bomb proof in the end. looked at mdf screws but decided on using more drywall/common course screws pre drilled and clutch driven.
 

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That jig c man did is very similar to one I built a while back. (cept mine doesn't have the clamp in it) It is a fantastic upgrade to a jig I already loved. Great time saver and VERY trusty. Good luck

Scott
 

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any links to a good homemade dado jig for router ?
Here's a good one. I can't post the plans themselves as they are copyrighted. They are only $5 and I don't want to get anybody's behind in a sling over it, especially mine:censored:.
Works really well but I modified it to use a 3/4" bushing to guide with rather than the router base itself. Problem I have with jigs that use the router base for a reference is now you have got the router and jig married. I just want them to like each other. Using a bushing, I can use any of the 5 or 6 routers I have with the jig.

Adjustable dado jig:
http://plansnow.com/adjustdado.html
 

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Discussion Starter #16
Update

MDF is not on my go to list anymore. Its ok... I had planned on using it for face frame too, but after building 1/2 the shelves i'm dreading it. I just need it to hold together long enough to get mounted where it will be glued and screwed.

I ended up dadoing all 4 shelf sides and it really was a must. No way my original design would have held up.

The jig jschaben posted is the way to go because my router base is off center. I have to align the router and be consistent on each cut. Anyone use a flush trim bit on a straight edge for dadoing?
 

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John
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Anyone use a flush trim bit on a straight edge for dadoing?
Yeah, you can do that with a shank mounted bearing flush trim bit, aka pattern bit. You do have to work out the cutting length of the bit, the depth of the dado and the thickness of your guide. :blink:
 

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For dado's I mostly use two pieces of 3/4 ply, about 8" wide by 28" long - cut square with a 1/2" stop bar added at the end of each piece. The pair are clamped to the work piece at the dado site, using the shelf thickness as a separation gauge. Clamp both to the work piece and use a pattern bit adjusted for depth for the cut. Very tight fit and allows for differences in shelf material thickness.
 
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