Monday 20 July 2015

How To Make A Sliding Dovetails Jig


Are you following Paul Sellers Woodworking Masterclasses, like me?

He is building a Shaker Style Stool (or bench) with sliding dovetails.

For making the sliding dovetails he is using a jig which is simply a piece of wood with an angled edge.

The question came up how to establish that angle to the block of wood with hand tools only and being precise.

Here is how I would do it....





I'm sure there are several methods to do it. The below described one made the most sense to me.

Here we go.....

How To Start


Take a piece of wood. Every wood species is fine. If you will have a strip of hardwood then use it.
But Spruce or Pine will work fine too.

Make all six sides square. Now you have have a reference face and edge.


6s wood block


Some Geometry


Now. Take a sliding bevel and a protractor. Set your sliding bevel to 10°. The angle is not critical. It doesn't matter if it is 9,5° or 11°.

90° - 10° = 80° on the protractor

Setting the sliding bevel
 
If you would read a German apprentice curriculum for cabinet makers, you will find the recommendation that the angle for a sliding bevel has to be 15°.

Usually Paul uses a ratio of 1:7 which results in an angle of about 8°.
Last but not least the only actual plane I know from ECE has got an angle of 9,5°.


Off We Go


Anyway. Take your piece of wood and scribe an angled line with the help of the sliding bevel to one of the ends.


Position it like this

Same setting, different perspective


Scribed line



Darken it for better visual effect


You have got two points on the outer edge now. A higher and a lower one.


Higher point

Lower point

Make some knife nicks. Like that....


Lower nick

Higher nick

Grab a marking gauge and set it from your reference edge to the higher point and scribe a line along the corresponding face.

Marking gauge on higher point

Scribed line
 
Done? Then set your marking gauge to the lower point and repeat the process of scribing a line but to the opposite face.

 
Marking gauge at lower point

Resulting scribe line


Easy, or?
Grab your plane and plane down to the lines. The closer you will come to your line the thinner your shavings should be. Possibly chose a shallower setting for your plane. 


Marked piece clamped into the vise

Start planing

After a few strokes

Check yourself - Uhhgg not the right anble ;-)

A few more strokes with corrected planing angle,

Getting better
 
As you will come to your scribed knife lines a so called feather edge will appear. Plane down to this edge and possibly one shaving more.


Feathered edge


If you will do this constantly then you will establish a nice angle which you can use for paring the dovetailed grooves and the dovetails.

Dead on


Check your progress regular with the set sliding bevel.

To train this procedure here is another hint.
Chose a shorter piece of wood. Do everything as described above.
But clamp your piece at an angle into your vise (see pictures above). That done you just have to pay attention to hold your plane horizontally. That makes it a lot easier. But this won't work with longer piece because your vice will not have such clamping capacities. But for practicing it is a helpful method.

That's it. Not more, not less.

I hope my description will help all new and inexperienced  woodworkers. If I can do that, you can do that too. It's a question of patience and thin shavings.


If you like this post, please feel free to share it.



Keep on making!

Stefan



2 comments:

  1. Great write-up, Stefan. Very clear. I'm on Paul Sellers WWMC, too, but I don't think I'll be working on the Shaker stool. I have no need for the project. (And a list of other projects to get to. - Matt

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    Replies
    1. Hi Matt,
      thank you for the praise. I'm not building the stool too. Even though I like the actual project because of the joinery and the techniques.

      Talk soon,
      Stefan

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