1) Choose well your habu : it can be an old one used full of splinters but not a broken one. You can see on the first picture this habu has supported too much damage to be use. You must use the flatter part of the habu and avoid knots. The curved part of the blade ; the Sori is not used.
2) Before cutting the blade make sure what size of you need because there are different sizes of sune. It is clearly better to take piece of wood of the exact size than the one you need to replace. Careful when you’re cutting blade, protect your eyes with glasses as there might be projections of wood.
3) Mark the four holes to attach the batten to the sune. You will need a drill with a size 5 bit to drill these. To drill a wooden board without splitting it, place a second board underneath and drill vertically. Your work surface must be stable.
4) Sand the lath, paying particular attention to the corners and holes you have created. Ideally, the corners of your batten should be rounded. Sand the entire lath, this will allow a better adhesion to the paint.
5) Paint the blade black with a spray paint can and let it rest. You should use spray paint instead of paintbrushes: the blade will react better to future blows from your opponents.
6) Attach the blade to the sune with a leather cord or a dark colored shoelace. The cord should be tight and straight. Try to make the knot as flat as possible. To prevent the knot from hurting you when you wear the sune, you can cover it with a bandage fastener.
article by Dylan Vellut and Laurence Dumonceau