To the man in the street, hand cut dovetails are the hallmark of fine furniture making. The first thing most people do when shown a piece of furniture is open the drawers and check for dovetails. Cutting dovetails by hand may seem too difficult, but with careful layout, precise sawing, a little practice and a few tricks and tips excellent results can be achieved.
Here is the method I use when cutting dovetails. I prefer to cut the tails first, although you may cut the pins first if you prefer (there is an ongoing woodworking argument over which is the best method!). Before you begin proper stock preparation is required. Cut the ends of the piece precisely square-a table saw, mitre-saw or even using a shooting board and hand plane will achieve this. Plane the edges square and the faces smooth and flat. Then you can begin laying out the joints.
Using a marking gauge set the depth to slightly more than the thickness of the pin board (in my example both pieces are the same thickness so I mark both pieces with the same setting). Run the mark around all four sides. Then using a small set square and either a bevel gauge or proprietary dovetail marking square mark out the layout lines for the tails. Try different tail widths to get a pleasing effect. I use a chisel to set the width of the pins, as this makes cutting out the waste easier. If the gap is narrower than your smallest chisel it makes cleaning out the waste difficult.
Clamp the tail board in the bench vice. I like to angle the board so that the cuts are aligned vertically. I saw half the cuts then turn the board so the other lines are vertical and cut those. When sawing aim to remove half of the lines, cutting in the waste side. This is difficult at first so some practice beforehand is useful. A fine set dovetail saw is the tool for this job, especially a rip-cut saw. As you are cutting through end-grain this makes for a faster, more accurate cut.
When you have cut the tails remove the outside half pins with the dovetail saw. Remember to stay on the waste side of the line. Remove the narrow waste between the tails with a coping saw or fine jewelers saw. Chop out any remaining waste using chisels. Place your chisel in the marking gauge lines to chop perfectly to the line. Ensure all waste is removed from the corners, using a sharp knife to remove any remaining fibres. Now you are ready to transfer the marks for the pins.
I use two 90 degree clamps to hold the boards in alignment while I mark around the tails. Using a knife, cut along the sides of the tails transferring the marks directly onto the pin board. Bring the marks down the face of the board to the base line we marked earlier using a small set square.
Mark the waste to ensure you don't cut out the wrong pieces and clamp the board in the bench vice. Using the dovetail saw cut the pins, making sure to cut in the waste side of the line. Remove the bulk of the waste with the coping saw and then cut back to the lines with chisels.
Both parts of the joint are now cut-double check that there is no waste fibres left in the corners and that you have cut the base line level all the way across. You are now ready to offer the pieces up to see how you've done. If you have cut right up to your marked lines you should be able to hammer the parts together. A little glue on the sides of the tails is all that is necessary as the strength of the joint is derived from its shape (and hopefully tight fit!)
Once the glue is set you can clean up the finished joint using a sharp hand plane. All that is left is to stand back and wait for the admiring comments!
The secret to tight fitting dovetails is accuracy-in stock preparation, marking out, cutting and fitting. Try a few practice joints and see which areas you need to work on. Once you've cut 3 or 4 you should be able to achieve excellent results.
