Using Pocket Holes

[John Adank]

I like to use pocket holes in some of my wood working but one thing that always frustrates me is how you can torque your alignment out of square when tightening your pocket screws. Case in point, I was was butt joining some drawers the other night with my Kreg jig and no matter what I tried the drawer parts would misalign or not be flush from the canting of the pocket hole screws. I used two of the vise grip style clamps but it still misaligned the drawer. I finally just switched over to butt joining the drawers with my Dowelmax. Not as quick but so much better alignment. I'm assuming this canting or torquing issue is just a drawback of using pocket holes.

[Lee Schierer]

I've not had this problem. Make sure your depth of cut is set right for your wood thickness. The tip of the screw should exit the board with the angled hole exactly in the center of the end. You also need to have the ends cut perfectly square, any angle will result in angle joints.

[Chris Padilla]

The key to pocket holes to make sure the mating pieces are secure when drilling the pockets. If not well secured, they can slip/creep slightly and give you the misalignment you are fighting and, yeah, no amount of clamping will fix the misdrilled joint.

[Dave Novak]

I use pocket screws a lot. Never when visible, but very frequently when they're hidden. I used to have the same problem until I realized how important Lee's suggestions above are as well as how to properly clamp/support the joint while tightening the screws.

[Peter Quinn]

For things like drawer boxes you can pop a few 18 ga brads to keep things in line too, or staples even. They are blind ultimately, the screws provide the holding power. I've also learned not to rely on the kreg clamps 100% and will often use traditional clamping methods to hold an assembly together before screwing it together. Clamps tend not to budge. For face frames the clamps work well enough, better still I've found is to make a right angle assembly jig like the one in the kreg literature using the clamp with the flush mounting plate. When assembling cabinet carcasses I definetly rely on k bodies more than the kreg right angle clamps, the vice grip type things just don't spread the holding force over a wide enough area to be affective. And once the screw is in the wrong place, fixing it is difficult for sure. So you are not alone on that learning curve , it is surmountable though.

[Bas Pluim]

Are you using an impact driver? I had the same issues with the pieces getting out of alignment, despite clamping the sap out of the wood. I then switched to using a regular drill/ driver, at a lower gear/ speed. This allows the screw to "drill" into the mating piece. That solved the problem for me.

[John Adank]

I'm using a regular drill driver. I will check the depth but I'm pretty sure I have it set to 3/4" thickness. I'm screwing together 3/4" plywood. Lee, can you expand on the screw placement comment? I don't understand how the screw should exit the board with the angled hole exactly in the center of the end. The board ends are square. I love cutting the ends on my new Festool Kapex miter saw.
thanks,
john

[Stephen Cherry]

I'm using a regular drill driver. I will check the depth but I'm pretty sure I have it set to 3/4" thickness. I'm screwing together 3/4" plywood. Lee, can you expand on the screw placement comment? I don't understand how the screw should exit the board with the angled hole exactly in the center of the end. The board ends are square. I love cutting the ends on my new Festool Kapex miter saw.
thanks,
john

I'll chime in with the setup, if that's OK. Basically, the kreg jig has three settings.

The first is related to the thickness of the board that is drilled. Basicaly, the little stops on the side of the jig are set to match this thickness, so that the drill bit center comes out of at the center.

The second and third settings are related to the thickness of the other board (the one not drilled). The idea is to set the collar on the side of the bit for good penetration into the other board, while maintaining a pocket that is not too deep. As the pocket gets too deep, a longer screw can be used.

Not very complex- the kreg website has a chart, and 1 1/4 works great for 3/4 stock.

[Phil Thien]

You really have to clamp the snot out of the two pieces when running the screw in. I'm not sure how much pressure those Kreg clamps apply, but I just use one or two bar clamps and don't have any problems with parts shifting.

[Paul Steiner]

+1 for clamping the snot out of things. I think I have at least one of every kreg clamp they make and use them all depending on the item. Especially when alignment is key I find myself using scrap wood for spacers and clamps to hold things. Which is ironic because if you have ever seen the Kreg infomericial on late night or early morning TV it says the Kreg screws eliminate the need for clamps. For face frames I high recommend using a bench mount or bench plate. Currently my favorite way to build case work with pocket holes is to make a shallow dado/rabbet (1/8, 1/4) and use micro pocket holes, this almost eliminates the need for the kreg clamps.

[Danny Thompson]

The point of the clamping discussion is this. The screw is exiting the end and penetrating the cross-piece at an angle. So, if a tiny gap is created during the drilling process (e.g., the screw is allowed to push the cross-piece before it penetrates) then the screw entry hole will be a little too far outboard (to the side away from pocket hole). Then, when the screw snugs up, the crosspiece will be drawn inboard as the exit hole and the entry hole mate up. This is not an issue when a screw is drilled into a normal countersunk hole, because the entry hole in the cross-piece is aligned with the screw.

Said a different way, a pocket hole screw pulls the cross-piece in 2 dimensions, while a normal screw pulls the target board in only one. Therefore, pocket screws have a greater potential for skew. To prevent this, make sure the target board stays snug to the board with the pocket holes, and drill slowly so the screw immediately bites into the target.

[Phil Erup]

I haven't experienced the problem, but I saw a custom cabinet build under construction a few months ago where the cabinet maker had made very shallow dado's to ensure that the box sides did not shift during assembly. This was a $75k remodel.

[Sam Murdoch]

Yes to good clamping. I use pocket screws mostly to assemble face frames and I tolerate no shifting. The Kreg quick clamps are just a start - I add whatever clamp(s) I can to hold my pieces tight to each other and/or to my work table. This no matter what I am using to drive the screws and wether coarse or fine thread. I do agree with Danny T that a slow start speed as you begin to drive the screw is very helpful. Otherwise - I love the pocket screws :)

[Todd Brewer]

I've not had this problem. Make sure your depth of cut is set right for your wood thickness. The tip of the screw should exit the board with the angled hole exactly in the center of the end. You also need to have the ends cut perfectly square, any angle will result in angle joints.

I bought my first Kreg jig about two weeks ago, Kreg Toolbox Master. I made a test joint with a 3/4" piece of poplar into a 3/4 inch piece of plywood. Jig set to 3/4", drill bit set to 3/4" at the shoulder. Screwed it together with 1 1/4" screw. Then tried to break it. It was pretty tough but did break (only one screw). Looking at the end of the poplar the screw was not exiting out the center of the wood, it was approximately 2/3rd of the way across, meaning it was entering the plywood near the outside edge. I ended up using 5/8" setting on the jig and setting the bit to 5/8" at the shoulder. The screw now exits out the center of the wood. I talked to the salesman about this but he admitted to never taking a joint apart to inspect the screw. Can't imagine I have a defective jig, they are pretty simple devices. Anyone else seen this?

Downside to using 5/8" setting on 3/4 material; the pre-made wood fillers are too long, unless they are meant to be.

And I agree, maintaining alignment is challenging!

[Charles McKinley]

The premade fillers are made to be trimmed to fit.

[glenn bradley]

Proper setup includes the screw geometry. The hole position should be such as the screw threads do not traverse the joint once tight. Solving for this parameter solved my "pulled out of line" issues.

[Lee Ludden]

I built most of my shop cabinets using the Kreg jig, and here is what worked well for me.

i put a light skim of glue on the joint, then clamp it as if it were a traditional joint. Once I am confident that everything is aligned, I drive the screws. The glue sets enough to help prevent any creep. I use parallel clamps for the clamping.

[Michael W. Clark]

I've actually found that turing the screw faster with light pressure to allow it to drill out some of the waste helps. You can tell when it starts to bite, then slow the speed and add pressure to drive the screw. You may also need to use parafin wax on the screws for hard wood to prevent splitting. I had a lot of trouble with splitting hard maple faceframes at the ends of the stiles with pocket screws until I started doing these things.

Mike

[Erik Christensen]

I gave up on Kreg alignment a long time ago - if I am going to use pocket hole screws I ALWAYS use a domino to maintain registration - a biscuit would server the same purpose if you do not have a festool domino.

[Lee Schierer]

I'm using a regular drill driver. I will check the depth but I'm pretty sure I have it set to 3/4" thickness. I'm screwing together 3/4" plywood. Lee, can you expand on the screw placement comment? I don't understand how the screw should exit the board with the angled hole exactly in the center of the end. The board ends are square. I love cutting the ends on my new Festool Kapex miter saw.
thanks,
john

Take a look at the diagram in Glenn Bradley's post above.

Also, no offense to Festool, but most factory settings on saws are just close. Do a tune up on the saw and check that it is cutting square in all regards. Cut to thick pieces of hard wood on the same side of the blade. Then flip one around end for end and bring the cut ends together on a flat surface. If you see any gap at all the saw is not cutting at 90 degrees..

[Todd Brewer]

I heard and read about so many people saying they no longer use their dowel or biscuit joiners after getting a pocket hole jig. I'm not convinced pocket screws are the ultimate solution. Biscuits give me some play for alignment, dowels if done right provide dead on accuracy. I do like not having to clamp and wait for glue to dry when using biscuits or dowels but typically I don't move things around much right after fastening anyway. I feel like I'm cheating using pocket screws. :) All three tools (don't own a domino) have their place.

[Sam Murdoch]

I heard and read about so many people saying they no longer use their dowel or biscuit joiners after getting a pocket hole jig. I'm not convinced pocket screws are the ultimate solution. Biscuits give me some play for alignment, dowels if done right provide dead on accuracy. I do like not having to clamp and wait for glue to dry when using biscuits or dowels but typically I don't move things around much right after fastening anyway. I feel like I'm cheating using pocket screws. :) All three tools (don't own a domino) have their place.

All 4 tools have their place - I completely agree.

[Peter Kelly]

Buy a Robertson screwdriver and try hand driving the screws on small pieces. You'll be amazed at how well it works.

Also, I don't think you need to crank down on anything that hard, just clamp a small stop block in place to prevent creep on a 90º joint.

[Prashun Patel]

In addition to clamping properly, which is #1, I drive the first screw only about 3/4 the way through, then to drive the 2nd (and others) all the way thru. The joint will be pulled tight but not out of position.

[frank shic]

i use the kreg only for building jigs and stuff that doesn't need to be spot-on accurate. i use the PC pocket drilling machine for everything else and have noted a marked improvement in accuracy of my joinery.

[Todd Brewer]

i use the kreg only for building jigs and stuff that doesn't need to be spot-on accurate. i use the PC pocket drilling machine for everything else and have noted a marked improvement in accuracy of my joinery.

Just watched a video on the PC jig. It's a different looking/style of jig but in the end it still drills angled holes just like the Kreg (as far as I can tell). I don't understand how it improves joint accuracy. Seems to me you still need to securely clamp the pieces. The video was of the PC jig not the machine. But doesn't a machine, be it PC or Kreg or other brand, simply speed up the drilling process by saving the time of having to pick up a drill? Please explain how a pocket hole machine vs. the portable jigs helps when it comes to screwing the two pieces of wood together.

[Stephen Cherry]

Just watched a video on the PC jig. It's a different looking/style of jig but in the end it still drills angled holes just like the Kreg (as far as I can tell). I don't understand how it improves joint accuracy. Seems to me you still need to securely clamp the pieces. The video was of the PC jig not the machine. But doesn't a machine, be it PC or Kreg or other brand, simply speed up the drilling process by saving the time of having to pick up a drill? Please explain how a pocket hole machine vs. the portable jigs helps when it comes to screwing the two pieces of wood together.

If it's the machine I'm thinking about, the Porter cable pocket machine is a small castle pocket holer. There have been heated "Ford-Chevy" style debates on other sites about the relative merits of kreg vs castle. There are others as well. I have a kreg pnumatic pocket holer, and can tell you that the big advantage is speed, and almost zero effort. Basically, you can drill a hole in just a couple of seconds by hitting a foot switch. So a board with two holes at each end takes maybe 10 seconds. It drills about the same hole as the jig though, but no fumbling around with the clamp and drill.

If you wanted to do real production, the other side of it is a pnumatic clamping table. Basically the two would work together to make faceframes very quickly, and it seems that the good clamps and solid table would not allow for much movement.

Basically, to sum up the castle vs kreg debate, you choose loud, long, neat hole in a complex machine (castle) vs. quiet, shorter hole, simple machine (kreg). The kreg is a little faster, as well.