|ROD BUILDING MASTERCLASS — Building a bamboo fly-rod, Part 3 — by Dirk de Villiers
FOLLOWING on from Part 2 in this series, you should now have 12 straightened bamboo strips that are ready for planing. A few words on sharpening plane blades are in order before we get started. I have to stress again the importance of extremely sharp plane blades when planing bamboo. Tearing of fibres at the nodes, strips sliding in the planing form and increased risk of bamboo-inflicted cuts are just a few of the consequences of blades that are not sufficiently sharp.
A number of efficient sharpening systems are available, so make use of one. All good sharpening systems will allow for the blade to be held at an exact angle while sharpening, and finish at extremely high grit numbers. One of the simplest and cheapest options is to use a simple sharpening jig and various grits of wet/dry paper down to 2000 grit.
Before starting to plane you need to adjust the block plane so that you can take shavings that are not excessively thick. Around 0.01” is about right to start with. As you get closer to the target dimensions you should retract the blade a little to reduce the thickness of the shavings.
Don a leather glove on your left hand. Now lay your first strip in the 90 degree groove of the rough planing form, as shown in picture 1. Start by holding the strip with your left hand while operating the plane with your right hand. It is a good idea to get into the habit of walking along the planing form rather than reaching to the end of the strip.
Always plane from butt to tip. The first few passes will create a 60 degree angle on one side of the strip (picture 2). As soon as the angle is beginning to take shape the planing form should be turned to a side that has a 60 degree groove. Now place the strip in the groove with the 60 degree side down and plane the opposite side (see picture 3). Continue, turning the strip regularly, until both sides of the strip have well defined 60 degree angles. Stop just before reaching the top of the planing form to prevent damage to the form (picture 4).
Now proceed until all the strips have been rough planed. These splines will all have a uniform size and no taper (picture 5). Remember not to plane the enamel side of the strips.
SETTING THE PLANING FORM
In order to create the tapered splines (six per section forming a hexagonal cross-section) the untapered splines have to be planed to dimension in a planing form.
A planing form consists of two steel or wooden bars with a depth adjustable, tapered 60 degree groove in the centre. One side will have a shallow groove for tip sections, while the other side will have a deeper groove for butt sections. In order to adjust the depth of the groove the form will have a system of push-pull bolts. A depth gauge on a flat, heavy base is placed over the groove and the bars are adjusted until the required depth setting is achieved.
Bamboo rod tapers are shown in a series of dimensions at 5” intervals and are expressed in 1 000ths of an inch. Divide these dimensions by half to get the required planing form depth settings.
Read the full story in the October 2012 issue of FLYFISHING.