Think Like a Trout, Act Like a Bug.

Monday, April 15, 2013

Part 5: Sanding to Taper


Aside from a few angling excursions over the past few weeks, I have also spent some time working on the wood fly rod build. The project continued with part 5 which involves sanding the rod blank down to the desired taper. This is one of the more intricate and lengthy stages of the process that is best accomplished by working on it a little at a time – sanding for a half hour or so whenever time allows. The goal at this stage is to bring the rod blank to a point where the rod has the general flex and action characteristics that you are looking for.  Part 6, the pseudo-lamination process, will stiffen it up just a little, but some final sanding in part 7 will bring it back to where you want it.

I do not use any measuring tools for this stage – I do everything by feel. Experience has taught me what to look for when it comes to rod action and flex characteristics, and I just go with my instincts. I am not even sure that precise measurements would enable anyone to reproduce specific rod actions with any degree of accuracy; unlike bamboo, there is just too much variation in the wood characteristics to allow for accurate reproduction using measurements. If you are just starting out, and need some sort of guidance, I would recommend having a fly rod of the action you are trying to produce close at hand, and use it to compare flex characteristics and action as you sand the wood blank to taper.

The sanding process is similar to the Initial Sanding; a piece of sandpaper is folded around the blank and worked back and forth as the blank is rotated. But unlike the initial sanding, where the goal was to simply produce an even taper, here you want to pay more attention to how the blank actually flexes. As you sand, you need to be constantly testing the blank by pressing the tip down on the ground and seeing/feeling how it flexes. A few casting strokes will also give you a good idea of the rod action. Generally you will end up with a blank that is relatively thin at the tip, evenly tapered into the middle section, and a quick taper to a thicker butt section. A simple even taper all along the blank will not produce a rod with even action or proper flex characteristics – the blank needs to be heavier in the bottom half of the rod to have the backbone to make a cast.
 
It is best to use 100 or 120 grit sandpaper for this work. Coarser sandpaper will certainly speed up the job but you will be left with deep scratches that will weaken the blank. In addition, slowing the sanding process makes it less likely that you will over-sand a section, rendering the blank useless. As you sand pay attention to how the blank flexes, and simply sand more where you need more flex, and less where you need less flex.
Two key areas that will need a little extra attention are the tip and the butt. The tip needs to have a good even flex with a tip fine enough to accept a 6.5 or 6.0 tip guide (usually the largest sizes available). The butt section needs to be heavy enough to provide backbone to the rod but thin enough to fit into the wood insert of the reel seat (the bore of the cork grip can usually be filed out to match the rod dimensions). I like to have a few different sizes of tip guides, and the reel seat/grip assembly on hand to ensure everything will fit together.

One final thing to be aware of is that even though the drying process may have resulted in an almost perfectly straight blank, the sanding process often releases tension as wood fibers are sanded away, resulting in some slight warping of the blank. This warping is unavoidable – and becomes a part of the character of each individual rod.
 
Once the rod has been sanded to the desired taper, it’s on to the pseudo-lamination process.

No comments:

Post a Comment