Pocket-hole assembling with Kreg Tools pocket-hole jigs
This week I’ve decided to introduce you to the assembly method which seems to gain more and more adepts in woodworking. Welcome the “pocket-hole” assembly method! This method has been popularized by the Kreg Company and its well known blue jigs.
There are many ways to make assemblies in woodworking. Each has its own advantages and disadvantages. We can easily think to the classical mortise and tenon, dovetails, half-lap joints, tongue and grooves, biscuits, etc. The success of some of these assemblies such as dovetails or mortise and tenon lies in the accuracy of the joint components: a tenon a bit too thick won’t fit into its mortise while a too thin tenon will fit in the mortise but won’t stay in place. You must achieve a perfect fit of both components which requires time and accuracy, so it can’t be repeated easily.
That’s where pocket-hole assembly becomes especially appealing. You get an easy and quick joint to realize that you can do over and over again. Furthermore, this joint only requires two things to make it: a drilling jig and a drill. The jig sells for a little under 150$ while any drill will be suited for the task.
The most renowned jigs in this area are without any contestation those produced by Kreg. This company has introduced its firts pocket-hole jig on the market around year 2000 and keeps on improving those. Actually the fifth generation appeared on the market about 18 months ago and is named Kreg jig K5. For my own part I used the third generation. It’s with the Kreg jig K3 model that the hype really started on. But no matter the version you use, the kit mainly includes the jig itself, a stepped drill bit, a stop collar, a screwdriver bit, some sample screws and sometimes a face clamp pliers-style and a storage case. You can also find more complete kits with a large screw assortment, the jig and its accessories and a more advanced storage case. Personally I added the Kreg Toolboxx that comes with the large screw assortment afterward and I put my jig into it. Doing so allow me to have all the stuff needed for that kind of assembly into a single box that I can take along with me.
The principle behind the jig is pretty simple. You place the piece to drill into the jig and lock it in place with the jig’s clamp. Then you put the stepped drill bit into the guide hole on the jig and drill until the stop collar comes into contact with the jig. You then repeat until all the needed holes are drilled. You must absolutely use the provide drill bit with the kit because a good part of the joint’s strength lies to its conception. This drill bit bores a hole a certain diameter on the most part of its length and close to the tip it creates a flat shoulder with a pilot hole in the middle suited for the screw shank size. Here is a picture of the drill bit:
During assembly the screw head which is like a washer will seat itself against the shoulder created by the drill bit creating a traction effect that will firmly hold your pieces together. It’s quick and easy. The jig guides the drill bit to specific angle into the workpiece giving you a hole looking just like this one:
One advantage of this technique is that you can use it on small pieces as well as on large panels and on nearly any thickness of pieces. You can in fact join different thicknesses pieces together or same thickness without any problems. You just need to set thing up properly and you’re done.
Speaking of adjustments those are a piece of cake and nearly foolproof. There are only two! The first one is performed on the jig. It has graduations engraved on the side and you just have to set it to the position corresponding to the thickness of the piece you’ll be drilling in and that’s the piece that will be held in the jig. The second one is done with the stop collar on the drill bit. A gauge on the jig’s base helps you adjust the collar for the thickness of the piece that will be screwed in.
Once setup is done you just need to put the stepped drill bit into the drill and the piece to be drilled in to the jig. Then use the drill to bore holes. For my own I worked mostly with hardwood species like oak, ash and maple. Because those woods are quite hard a cordless drill was often draining out its batteries in no time. So I ended up buying a cheap 3/8″ corded drill that only gets used for this purpose but it never gets out of power and it’s lighter than a corded one.
Once holes have been drilled, assembly is a matter of aligning pieces and driving screws in. After a while working with the system I learned to use some precautions during assembly. I always put my pieces in place with clamps before screwing if the final assembly is a corner shaped one like on the previous picture which is one of my workbench’s legs made 2 years ago. The angle of the hole and the traction of the screw always lead to slight movement of pieces if not well maintained in place. For a flat lying assembly I either use the face clamp provided in the kit or the clamping plate recessed on my workbench’s top:
With this one there is no way pieces can move around while screwing!
For the screws I always use Kreg ones for 2 reasons. First there is screw quality on itself. I tried regular rounded head screws and I quickly noticed that the head is often misshaped and the screw driver bit slips. With Kreg ones I never have this problem. Secondly Kreg screws do have a slotted tip that prevents wood splitting on the second piece which has not been drilled. You avoid nasty surprises and material waste. Furthermore they do not cost more than regular screws. Because I bought the Kreg Toolboxx I have quite all sizes on hand and when quantities get low for a model I quickly replenish my supply. I also bought a simple tool but oh so useful:
This little wheel allows you to know which type and size of screw to use for an assembly. You just have to dial in the thicknesses of your workpieces that you want to join and you’ll see the scre size and type to use in the little window. Bingo, couldn’t get simpler than that! That’s another good reason for me to use Kreg screws. I went a step further and labelled every screw bin in my Kreg Toolbox with the exact codes used by Kreg. I can then quickly pick the one dictated by the wheel.
Well since I discovered this system I use it nearly on every project. It speeds up assembly. On my entertainment center completed lastly all the face frames on every modules have been assembled laying flat on my workbench with Kreg pocket-holes and the joined to the modules using biscuits. Quick and easy! 2 years ago I made a study desk for my kids to do their homeworks. I needed something quick since I had very little time for the project. I assembled the whole project with pocket-hole technique. If needed, I could take it apart and back together in just under 15 minutes. Practical isn’t it? To conclude here is a picture of the storage case blow my workbench. It is assembled using only pocket-hole screws again. Once panels were cut to size, I needed only an hour to get this result:
Here is a list of links to different Kreg products on Elite Tools website:
- An overview of available Kreg products:
- The different Kreg drilling jigs : http://www.elitetools.ca/en/category/kreg-category/kreg-jig/
- Screws and plugs in various wood species to hide screw holes :
- The screw selection wheel:
Unfortunately I cannot pus a link for the Kreg Toolboxx since it has been discontinued. However HomeDepot sells a toolbox looking exactly the same as the Kreg one but without the Kreg logo on it and screws:
It is still an excellent solution to keep all your stuff together. There is also always a chance that Kreg decides to reissue the Toolboxx. Who knows?
Until next time, I wish you good wood working!