A few notes on rattan:
Rattan is a tropical vine that grows in sandy soil. As such, it is flexible and highly fibrous with a grain more like celery than any American-grown lumber. It is highly flexible with the least flexible portion of the plant in the skin. Due to the sandy soil it grows in, rattan often contains small particles of silicate within the wood. Any tools used to cut or shape rattan will require more sharpening than usual and can ruin tools if care is not taken.
Because rattan does not grow perfectly strait, all measurements and markings will be based off center lines instead of measuring from an edge. Anyone using power tools is advised to avoid using a measuring fence on the first few cuts. When cutting skin-on rattan with a fence: the fence will cause the blade to follow the imperfections and curves on the surface of the wood. This has led to the myth that cut rattan warps - it does, but not more than uncut rattan or any other type of wood.
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Start with a strait piece of rattan at least two inches in diameter. This will be heavy and very stiff but shaping will reduce both of those qualities. Mark the center on both ends and two perpendicular lines (+). Draw a centerline.
If you are turning rattan on a lathe, it is advised you do your lathe work first because the rattan is stiffest with most of the skin still on. It should be possible to turn an 8" handle on a 32" piece of rattan without difficulty. Due to its flexibility, it is not recommended that you attempt to turn rattan longer than 36". Set the lathe to rotate at a slow speed. Because most lathes are air-cooled and cool better at higher speeds, take frequent breaks to keep the lathe from overheating. Because of the silicate in the rattan, blades will heat up and can lose temper. Also heated rattan shavings will produce glowing embers that will set your shaving bin on fire if not monitored.
Once the lathe work is done, mark a point 3/4" over from your centerline at the base of the blade and 11/16" from the centerline at the tip. Cut your flats. Do not let the wood rotate while cutting. Your blade should have a flat distal taper and be 1.5" wide at the base and 1 3/8" wide at the tip. Using the + on the end on the rattan as a guide, mark a new centerline on the flats.
For a 2" wide strait blade, mark a point 1" over from your new centerline and cut the sides. If you want a linear taper or a leaf-blade, mark that instead.
Down the center of the edge of the blade mark two parallel lines 3/4" apart.
Using a drawknife, plane, spokeshave or other shaping tool, remove the rattan between the edge lines and the centerline on the flat.
Check your cuts with a marshal's gauge. If the rattan is too thin, throw it out and start over. The pictured rattan below fails.
Use a compass, lid or other 1.25" diameter round object to mark a circle centered on the tip of the sword. Mark a point 2-3" back from the tip and shave the tip down to the circle you drew.
Using a spokeshave and/or 60 grit sandpaper to smooth out any high points, slide the guard down the blade. Sliding the guard down the blade allows you to shape the wooden portion of the hilt so that the guard will never slide down onto your hand.
Check your cuts with a marshal's gauge. If the rattan passed your first test but is now too thin, it may be thick enough to build back up with tape. If not, throw it out and start over.
Remove all sharp corners near the edge of the blade. Insufficiently rounded corners hurt your friends. At a minimum, it should not be possible to touch the bottom of a 1" wide x 1/2" deep slot with any portion of the waster.
Drill a hole in the handle and glue in a 1/2" x 2" carriage bolt for balance. .
Stain the handle, add a thrusting tip and tape the blade with strapping tape and duct tape.
To protect the edge from cuts, you can add a strip of leather or siloflex between the strapping tape and outer tape layers as neither material reduces the flexibility of the rattan. Do not use metal tape, but mylar "chrome" duct tape is acceptable for the outermost layer.
Check your waster with a marshal's gauge one last time. If the rattan passed your first test but is now too thin, it may be thick enough to build back up with more tape. If not, throw it out and start over. A gladius shaped like this will be closer in weight to a 1.25" diameter skin-on baton than the log you started with, but will much be stiffer than the 1.25" baton. Adjust force levels appropiately.