From this to this. Using a planing form, the .25” straightened and dried strips are now ready to be hand planed down to an itty-bitty 0.03125" triangle.
Planing forms have a variable depth 60 degree “V” shaped channel filed between the bars to hold bamboo strips while planing. The tip side's channel tapers from .03125" to .117", the butt side's channel tapers from.117" to .144". One side of the form is for butt sections and the other for tip sections.
Seeking perfection, I decided to build a “professional” set of planing forms. Started with two 1”sq by 72” cold rolled steel bars.
I used a very aggressive 14” Mill Bastard File to form the channel. The channel angle is guided by a wood block cut at a 30 degree angle. Channel shoulder depth is accurately measured with a micrometer. Bolts hold the two bars together and allow the channel depths be adjusted within .001” tolerances.
It is imperative to smooth the planing surfaces so your plane blade does not gouge the metal surface and dull the plane blade. I used my Porter Cable 4 x 24” belt sander with #36 and #80 grit. It’s a beast and it gets the job done so much faster than a using a hand held metal file. There is a link on my Final Thoughts page explaining form building in excrutiatingly minute detail.
There are about a zillion bamboo rod tapers out there. This chart was a starting point for me and I have since developed my own tapers for four, five and six weight rods.
I'm holding 48" long strips for the tip section and butt section. The tip section strip measures .03125" at one end and .117" at the other end. Butt section strip is .117" at one end and .144" at the other.