Sliding Dovetail

Step 1: Measure and mark out Dovetail Tenon 

The height of the dovetail tenon is slightly greater than the thickness of the mortise piece – to avoid a sunken tenon. Mark on all 4 sides.

On the end grain, draw the shape of your dovetail tenon. The thickness of the dovetail tenon will be smaller than the mortise piece (e.g. half its thickness).

A dovetail marker can be used to lay down the angles of the dovetail tenon. Mirror this angled line, across the end grain of the tenon piece, to form a clear dovetail shape. Shade or cross out the waste areas.

Step 2: Saw Dovetail Tenon cheek & shoulders

Next, brace the tenon piece against a holdfast or stop block horizontally. Remove the waste material to reveal the rough shape of the tenon and its shoulders.

Step 3: Pare Dovetail Tenon

Pare the edges of the dovetail tenon down to the drawn lines.

There is likely to be an upward slope of material from the newly pared end to shoulders of the tenon. Pare tenon faces until flat.

Check the straightness of the tenon using a try-square or the length of a chisel.

Step 4: Clean up Dovetail Tenon  

Lay down a knife line on the line defining the tenon’s height and chop to refine the tenon shoulders. 

Check for flatness of the tenon shoulders and pare any remaining excess.

Step 6: Marking and Sawing Dovetail mortise

Mark the thickness of the tenon piece on all 4 sides of the mortise piece. Next, align the tenon piece on the marking and trace the wider side of the tenon, within the marking, on all 4 sides.

Align the thinner side of the tenon flush with the edge of the mortise piece and trace the angled shape of the dovetail tenon.

Mirror this dovetail shape on the opposing side of the mortise piece and join the ends of the angled lines with a try-square.

Shade or cross out the waste material.

Brace the mortise piece horizontally and pay attention to the angle of the tenon.

Further break up the waste material by sawing in between the two previous cuts – to make chopping of material in the next step easier.

Step 7: Chop Dovetail mortise

Create a knife line along the base of the mortise.

Chop downwards with the chisel perpendicular at the rough halfway mark in the waste material. Repeat to remove bulk material beyond the knife line.

Repeat step 3 to pare the edges of the mortise down to the drawn line.

Step 8: Fitting the joint

Being able to fit the tenon up to its halfway mark by hand alone is indicative of a good fit.

Otherwise, remove the tenon and examine for burnish marks indicative of excess material (if the walls of the mortise or tenon are not properly flattened).