Woodwork Tools Blog

Jul

28

The Doweling Jig

Once a common sight in woodworking workshops, the doweling jig is now less commonly seen, as many woodworkers have been quick to adopt the biscuit jointer as their preferred method of joining boards together. Despite this, dowel joints are still an acceptable, strong method of joining boards together. I have owned a doweling jig for many years now, and although it is one of the cheaper models that are available, it still gets put to work and is capable of creating strong and accurate joints.

The doweling jig I use is shown below. Shown on the right is the clamp that is attached to the stock to be joined. The components on the left are the drill guides, allowing for different size drill bits (and therefore dowels) to be used, and there is also a depth stop that can be attached to the drill bit.

My Basic Doweling Jig Set

My Basic Doweling Jig Set. Drill guides, Depth Stop and Clamping jig

The first step in using a doweling jig of this type is to line up the boards to be joined as they will be when the join is complete. Hold them in position, and then mark both boards where they touch at the points where you intend to place the dowel joints. Make sure you mark both boards, and that the boards don’t move in between marking the different dowel locations.

Marking Dowel Position on Adjoining Stock

Marking Dowel Position on Stock to be Joined

Next set up your dowel jig.

Select the correct size drill guide for the dowel you are using, and clamp it into the jig using the wing screw. At the same time, you will want to adjust the position of the drill guide so that the drill will enter the timber in the middle of the width of the boards to be joined. How accurate you need to be in lining this up with the center will depend on the stock you are joining. In the images, I am joining some old framing lumber, which is almost 2 inches thick, so I wasn’t too concerned about how accurately it lined up with the center of the board. On thinner stock, you will need to take more care with this. Once positioned, tighten the wing nut, and MAKE SURE IT DOESN’T MOVE FROM NOW ON! If the location of the drill guide moves once you have already started drilling, this will cause you later holes to be out of alignment. There is an easy fix for this – just go back to an earlier hole, put your drill bit in the hole, and then re-locate the drill guide based on the position of the drill – it is still easier to make sure it doesn’t move though!

Top View of Doweling Jig In Position

Doweling jig set up and in position on one piece of timber to be joined. Here I am using a 10mm dowel, and have roughly centered the drill guide on the board. Take more care with this if the boards are thinner!

Once the dowel jig is set up, the next step is to locate it on the board. Working with the clamp on the reverse side of the timber (ie not the face side), this is a simple matter of lining up the pencil mark that was scribed earlier in the “V” on the doweling jig. Once it is lined up, tighten the clamp to ensure that the jig doesn’t move while you’re working.

Lining Up Dowel Jig with Dowel Position Pencil Mark

Lining Up Dowel Jig with Dowel Position Pencil Mark

Detail of Lining up Dowel Position Mark with Doweling Jig

Detail of Lining up Dowel Position Mark with Doweling Jig. The pencil mark is clearly visible in the center of the “V” of the doweling jig

From here, it is simple a matter of drilling the holes. Generally I aim to have about half of the dowel in each piece of timber being joined, but if joining stock of different sizes in a 90 Degree box joint, this is not always practical. Being an old fashioned style woodworker (and also not wanting to wake any sleeping children)  tend to like using a brace and bit to drill the holes. Here I am using a depth stop on the drill bit to ensure that the holes are the same depth.

Using Brace and Bit with Depth Gauge to Drill Dowel Hole Using Doweling Jig

Using Brace and Bit with Depth Gauge to Drill Dowel Hole Using Doweling Jig. The Depth stop is set so that roughly half the dowel will be in either side of the joint.

Repeat the above process of lining up and drilling for each of the locations that you marked on the first piece of timber. The result will be a set of neat holes, consistently placed the same distance from the face edge.

Consistently Positioned Dowel Holes Thanks to the Doweling Jig

Consistently Positioned Dowel Holes Thanks to the Doweling Jig

Once you have completed the first board to be joined, you will then have to repeat the process on the second board, lining up the “V” with the pencil marks, and drilling. The only trick here is to ensure that you are still working from the face edge of the timber. This isn’t too hard to remember, as the pencil lines should only be on the face edge, but it is always worth mentioning things that shouldn’t have to be mentioned!

Some tips on getting the best joints when using a doweling jig:

  • Make sure you are working with timber that is well jointed (ie has 2 square faces you can work from)
  • if you don’t have fluted (ribbed) dowel, using a handsaw, make a small cut 1-2mm deep down the side of your dowel along the length of it. This will allow any excess glue to escape, and will prevent any joints coming apart due to built up pressure from glue compressed in the clamping process
  • as with most woodworking, clearly mark your face sides, and always work from these sides to ensure that the dowel joints line up correctly
  • measure twice (or three times) and drill once, also, do a dry run of assembling your joint prior to adding the glue – just make sure you can get them apart again without damage!

All in all, the dowel joint is a simple, yet strong and effective method of joining timber together. A doweling jig makes the process a lot easier, as you can be confident that you will get accurately positioned holes that will line up when you go to assemble the joint. The simple doweling jig I have shown here is quite effective for joining boards. Similar ones can be found on Amazon such as the self centering “Premium Doweling Jig” (pic below – click to view on Amazon):

The downside of this jig and jigs like it is that you are limited in the size of the timber that it can be used on. If you want to create a 90 degree joint eg a table leg to a table top, it really isn’t possible with jigs of this type. You can use a set of dowel center transfer plugs to transfer the location of the holes you have drilled in one piece, but you really lose accuracy when you do this, which leads to poorer quality joints.

If (and when 🙂 ) I am buying a doweling jig again, then I will go for something more like the “Joint Genie” (see pic below – click to view on Amazon)

 

Or the “Dowelmax” precision jointing system (pic below – click to view on Amazon):

Whilst these are more expensive, they will certainly pay itself off in terms of quality of finish and flexibility! As with most tools, I find paying more up front may be more painful initially, but over time it is really worth it.

Enjoy your woodwork tools!

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