Introduction: How to Prepare Sunrise Dovetails (Japanese Dovetails)
Read the Instructable, and watch the video, on how I make this Sunrise Dovetail joint, then try it yourself.
Looks impossible? That's simply an illusion.
It isn't easy to get your head around at first sight, but once you've read the instructions and seen the video, it should be a lot clearer.
Step 1: Cut Your Blanks
You'll need two boards to join
They should be prepared square and true (videos on this can be found on my youtube channel if necessary)
The same width and thickness is recommended for your first attempt, but I'm using pieces of different thickness here (it makes no difference to the instructions)
Step 2: Gauge Thickness
Use a marking gauge to scribe a line around the end of each joining piece that is the thickness of the mating piece away from the joint end
You can just use the mating pieces directly, by standing the piece to me scribed on end, and laying the other piece flat and against it. Then draw a flat knife across where the pieces meet. Do this all the way around each of the joining ends
Step 3: Place a Centre Line
To ensure that the dovetail is centrally located, and aligned on both pieces, a centre line should be struck through the width of each end (and down the face to the gauged line)
Measure to find the mid-point, then use a marking knife and try-square to place centre lines on both pieces
Of course, should you wish to place multiple sunrise dovetails along a joint, you can lay in centre lines for each of them
Step 4: Offset From Centre Line - the Central Pin
The middle of the dovetail is the central pin. Therefore to lay this in you have to mark off half the pin width from the centre lines
Set a pair of dividers to half the wide end of the pin, and mark it off from the centre lines at the edges which will be furthest from the joints outside corner
In the photo, you'll see that I keep the 'inside face' to 'inside face' while doing the end grain marking out. That way, the wide end of the pins is always where the pieces meet
Set the dividers to half the narrow end of the pin, and mark it off from the centre lines at the edges which will be nearest to the joints outside corner
Step 5: Mark Off Pin Ends on End Grain
Reset the dividers to the full width of the thick end of the pins, and mark these off from the central pin (each gap being equal to the same measurement)
Do the same for the narrow ends of the pins
Now it's possible to 'join-the-dots' and mark in the pins on the two end grains, preferably with a marking knife
Step 6: Pin Ends on Faces
Use the previous method to mark in the wide pin ends on the outside faces of each piece, at the gauged line
Join all the pin ends up using a marking knife
The photo shows the marking in pencil, for higher contrast, but the thickness of pencil lines can lead to inaccuracies
Now mark in all the waste areas - take particular care, and use the diagram shown if needed
Step 7: Saw Out Waste
A fine Japanese dovetail saw has a thin enough kerf that you can probably saw right on the lines, but if using a thicker kerfed saw then saw towards the waste side of the lines
Saw each side of all the pins, following the two marked lines on the face and end of each piece and then completing the cut down the inside face, using the first half of the cut to guide the saw
Saw off the waste from the two outside edges of the one piece, following the gauged lines
Use a jeweller's or fret saw to cut across at the base of the waste between pins, leaving the gauged lines to be cleaned up in the next step
Step 8: Pare Away Remaining Waste & Fit
With sharp chisels, pare away the remaining waste, back to the gauged lines, ensuring that no 'hump' is left in the joint between the gauged lines (this would prevent the joint fully closing)
Some finessing of the mating surfaces may need to be made to allow the joint to be assembled, since the large surfaces present a lot of friction. Make adjustments bit by bit, trying frequently
Once fit, apply glue to all mating surfaces and assemble
Depending on the wood used, you may need to chop the waste out. If so, remember that the slots are all angled
Step 9: Finish
A few shavings with a smoothing plane should remove the gauged lines and flush the pins nicely
You can see how this, my second attempt, is much improved over the first sunrise dovetail I made! Don't be discouraged if your first one looks a mess
A little polish, and it doesn't look too bad
Thanks for reading my instructable, and don't forget to watch the video!
There are more joints to see on my YouTube channel (forty two at last count), and also some others here as instructables
Cheers,
Mitch