from The Wise Fisherman's Encyclopedia
The taper figures given above infer the rate at which the diameter changes per linear foot. Individual strips, of course, will measure but half this amount. A sense of proportion must be exercised in the design of any rod. For example, it would be utterly ridiculous to design a 7-foot fly rod with a tip much larger than 1/16" (.062) Suggested tip diameters for various fly rod lengths are:
These are given as beginning points, a tolerance of several thousandths of an inch either way being perfectly proper.
DESIGNING A ROD
When beginning the design of a new rod, obtain a few sheets of graph paper identified as "10 x 10 to the 1/2 inch" which can be purchased at any school supply or stationary store. Mark rod length across the top (or bottom), placing each six-inch interval a half inch (ten spaces) apart. Along the left margin, starting with zero at the bottom, designate each vertical half inch (ten unit space) twenty thousandths of an inch. Therefore, the small spaces will each represent two thousandths (.002 ") inch. Along the right-hand margin designate each half inch space as forty thousandths (.040") inch. You will notice, then, that this simply doubles the number on the left-hand end of a given line. In this way, either the f ull rod diameter or the strip dimension may be seen at a glance. To take an example (Figure 20) we shall design a fly rod of 81/2-feet length or medium action. Starting at the tip and taking advantage of the tolerance mentioned above, .078" (5/64") will be chosen. The line marked 102" is followed down until it intersects .078", and a dot is placed at this point. The taper corresponding to medium action is given as .028" to .033" per foot. We shall choose middle-of-the- road figure .030".
To arrive at the butt diameter, multiply this figure by eight and one-half, the rod length. Thus .030" x 8.5 = .255" which represents the amount of "growth" from tip to butt. To find the actual diameter, this figure must be added to the tip size .255" plus .078" equals .333'S Dividing .333" by 2 gives us the strip size, which is marked on the left side (vertical line denoting zero length, end of butt) of the sheet.
Two points have been determined through which a straight line should be drawn. Since this is to be a two-piece rod, the ferrule will be situated at midpoint, 51". At this position, our sloping line has a vertical value (diameter) of .203", or almost exactly 13/64", a standard ferrule size. Remembering that our pet rod broke last summer at the mouth of the male ferrule, or "slide," we shall compensate for the local weakness by installing the next size, or 14/64" (.218"). This is blocked in approximately to proper scale regards length. From a point 6" either side of the 51" station, short lines are drawn from the curve (taper line) to their respective ferrule ends. A local "beefing up" at an erstwhile critical zone has thus been accomplished.
Combined handle and reel seat assembly will be 12" long. Taper under the cork grip is of no concern, so this remains straight. Cork rings for grips being obtainable only with fraction-sized holes, we find that 11/32" (.343") not only nearly approaching the terminus of the graph (.333"), but providing enough bamboo within for a solid feel. In a distance of three inches beyond the cork grip, the diameter is sharply decreased. This is the familiar "swelled butt" that is incorporated on most modern bamboo rods. A basic rod has been designed.
Alterations can be made. For a more flexible tip, for instance, employ the next smaller ferrule 13/64" (.203") and reduce the diameter slightly throughout length of the tip section. As pointed out previously, the tip strength will be considerably diminished particularly at the ferrule. For those who prefer tip action rods, there is no compromise. In any event, draw the basic straight line first. Then make deviations with respect to this as a reference point or a starting point. Furthermore, never makc abrupt taper changes except as in the "beefing-up" treatment at the ferrule. Draw smooth, gradual curves, remembering that small changes, particularly toward the tip, bring about large changes in deflection and strength.
The purpose of the above was to acquaint the serious amateur rod maker with a
method by which he can begin; a method whereby a constant, fixed measuring stick
is always available, rather than to set forth a tabulation of suggested calibrations.
The latter curbs enterprise and the exercise of one's imagination.
Remember, finally, that practically every worthwhile modern invention is the product of an amateur who had an idea.
MAKING THE ROD
Selecting Bamboo. Unfortunately, raw bamboo stock is not generally available. Rod
manufacturers will occasionally satisfy one's needs as will a few mail order firms who are
engaged in this business. In any event, specify an outside diameter of from 1Ό" to 13/4".
The weight of first-class bamboo in this category averages ½ pound per foot. A 6-foot
culm, then, should weigh from 2 pounds 10 ounces to 3 pounds 2 ounces. If. it falls within
this weight range, the cane can be assumed to be of good structure and density.
Secondly, the stalk should be reasonably straight. A straight edge bridging two adjacent nodes should come within, perhaps 5A6" of the cane surface. Surface flaws are always present in one form or another: decay, cuts, stains, cracks, etc. Far E a s t e r n exporters frequently straighten badly formed pieces by heating and bending. This is always evi- denced by a presence of scorched area which is frequently crushed in the process. If such stock is received, return for exchange. If stock is to be kept in storage, saw a slot through one wall down the entire length of the culm. Contraction due to drying will frequently cause cracks to appear in profusion.
Cut the culm to length allowing a foot or more for node staggering, handling, trimming, etc. If the culm is to be split, a heavy knife is well.centered against one end. The blade is given a blow with a block of wood and forced into the crack as far as it will go, urged onward, if necessary, by repeated application of the block. A strong twist of the blade is sometimes necessary to break through a node. When split in halves, these are again split in half until the desired width is realized. The rod builder who has access to a circular saw should first spend an hour to make the wooden sawing fixture illustrated in Figure 21. In use the saw blade is centered in the slot at the bottom of the fixture. The ripping fence is then brought alongside and locked. The saw blade height is then adjusted, to cut through the bamboo wall only leaving the partitions at the nodes more or less intact. These, as the sawing progresses, hold the several strips together until the operation is finished. The culm is laid in the wide V. being held securely. The fixture, carrying the bamboo stalk along with it, is then pushed through. A lengthwise cut is thus produced through the cane wall at the bottom. The culm is then turned slightly according to the width of strip desired, and a second cut is made, and so on, until the starting point is reached. Unless badly split previously, all strips will be retained by the nodal partitions. A sharp rap against the surface of the workbench will break these apart.
Chop off remaining inside node structure with a heavy knife until flush with adjacent surfaces. Insert the strip (whether split or sawn) in a vise, enamel side up. Using the "Vulcan" or aluminum file, dress the outside node growth flush, using lengthwise strokes. Since the nodal areas are weakest, they must be spaced apart from each other.
There are two ways of doing this: the alternating system and the spiral system. The former can be used only on four or six strip rods, while the latter may be used on a rod or section of any number of strips.
Alternate Node Staggering. Select the number of strips to be used. Place these, enamel side up, on the workbench parallel to each other. Since all strips came from the same culm, all nodes will be in alignment, that is, opposite corresponding nodes on adjacent pieces. Push every other strip to the left, half a node-length. Three nodes, if a six-sided rod is under way, will be opposite each other, but separated by unimpaired fiber. Bundled in such a manner as to preserve this lengthwise adjustment, all ends are sawed flush.
Spiral Node Staggering. Lay strips across bench as above. Move the second strip an inch to the left, the third an inch beyond the first, and so on. Make sure after moving the last that this does not bring a node opposite a node on the first piece. Examine the entire group for this condition. If satisfactory, number each in its proper sequence, bundle together as before (without lengthwise shifting) and saw both ends flush. Preserve the marks, as the section must be assembled in this manner after planing. In this way five continuously-fibered strips support each nodal area.
Heat Treatment. This is a subject of diverse opinion among various rod builders. One faction holds that a short, intense cycle should be given, while the other adheres to a policy of less temperature for a relatively long time. All agree that, regardless of method, excess moisture must be eliminated in order to realize increased stiffness of the material. An open gas flame has been used to treat cane in the culm form. When sawed strips are to be treated, a closed receptacle of some sort is necessary to prevent burning or local charring. A length of 3-4" pipe, loosely capped at the ends to allow the escape of water vapor, is widely used by amateur and semi-professional rod makers. A layer of asbestos sheet should first be placed on the bottom to prevent contact of the bamboo with the hot metal. The pipe is then placed over a gas burner. As the air within becomes hot, water will be forced Out of the bamboo fiber and escapes past the loosely fitting end caps in the form of vapor or steam.
Temperature for the first hour should not exceed 225 F. A rough estimate may be made by sprinkling a few drops of water vapor, (sic) is widely used by amateur pipe. If a drop boils violently, reduce heat. The temperature will be about right if a few tiny bubbles form within the drop, these growing until the drop commences to boil and then disappears.
If desired, a brown color may be obtained by increasing the temperature to the region of 300 F to 350 F. A fat frying thermometer (range 100 F to 500 F) or a candy thermometer (range 100 F to 350 F) will eliminate any doubt as to the temperature inside the heat treating oven. Either of these are available in most stores handling house furnishings. A slot or hole should be provided at one end of the pipe for insertion of the thermometer.
Lacking a thermometer an approximate method of measuring temperature must be used. A drop of olive oil placed on the hot metal surface will begin to smoke in the region of 300 F; animal fat, 350 F. Variations exist, to be sure, but it should be assumed that an excessive temperature prevails if the vegetable fat vaporizes visibly, and the flame must accordingly be adjusted lower. Temperatures above
375 F, if maintained for an appreciable length of time, will deteriorate bamboo strength rapidly. One hour at any temperature from 300 F to 350 F will change color of bamboo very slightly, while a considerable effect will be noticed after three hours. At the conclusion of the heating cycle, the strips are removed from the "muffle" (which is the proper term for this heating contrivance) and are spread out on a flat surface to cool.
Heat treating equipment used by the modern rod manufacturer, the method by which the cycle is calculated, and the determination of moisture content are, for obvious reasons, beyond the scope and purse of the amateur.
Planing. Those who have not previously worked with bamboo should first
experiment with several scrap strips. The fingers of the hand holding the bamboo
strip should be protected from splinters and sharp edges, for the latter can inflect a
severe gash if drawn across the flesh. While pressing the strip into the formed
grooves of the planing form, exert strong pressure with the thumb or fingers. Then,
in the event the blade "catches" in the work, no slippage will occur. Although
uncomfortable to wear, heavy electrician's rubber gloves afford ample protection.
Finger "cots" (individual leather or rubber-faced finger coverings) are quite comfortable, protect adequately, and are inexpensive.
The first and most difficult problem in hand planing is making the "apex," or angle formed by the
two flanks (flat sides) adjacent to the outer "enamel" side of the strip. Lay a sawn strip place in one
of the larger grooves of planing form, with the enamel sun against one side of the "V" (Note Figure
22). A few strokes are taken with the plane, resting the heel of the tool on the surface of the planing
form. Adjust the strip lengthwise in the groove as necessary to plane the whole length.
Press the blade down hard against the work, forcing it tightly into the form. When a portion of the corner is removed, place the enamel side against the other flank of the "V" and proceed as before. This reversal should be done frequently.
As the inner, (pith) sides are cut away, forming an angle, the thread center gauge shoud be applied in order to check progress. The strip will almost invariably fail to contact the gauge at the bottom of the groove. Set the plane blade for a finer cut and position the strip so as to bring the enamel edge slightly above the surface of the form. Modify both sides until the shaving equals the width of the bamboo flank. Recheck. Now, using the micrometer caliper, measure across corners. These should be equal. An exaggerated condition of error is shown in Figure 23. Once the angle has been made to properly fit the center gauge, tapering according to the graph follows. At this stage the depth of cut will probably again have been reduced. During the process, remember to work on alternate sides every few strokes. Removal of the last few thousandths requires an extremely sharp set to the plane so that it
will cut a very thin shaving only when considerable force is applied.
High areas may be smudged with a soft pencil, then only the marked portion planed off. Each spline should be shaped in a similar manner, first producing the angle and then tapering as the design dictates.
Contrary grain in the vicinity of the nodes and elsewhere is occasionally troublesome. Resharpening or adjustment for a thinner shaving often cures the splintering. Holding the plane at a steep angle (skidwise) sometimes shears the unruly fibers cleanly. Grade 2~0 sandpaper wrapped tightly about a block will rectify the most stubborn case. Use of the sanding block should be restricted to local corrective work, as the planing form is usually unwittingly sanded in the processes, destroying its originally accurate figure.
A trial assembly will, in all likelihood, reveal small voids or seams here and there along the section. This is understandable when one considers the fact that a small error repeated in four, five, ot six strips will add up to noticeable gap along one seam; five adjacent flat sides will fit quite properly beside each other, with the first and last failing to make contact and creating a narrow wedge-shaped void. Small splinters inadvertently broken from the planed edges produce a similar outside appearance, but are quite as sound as a perfect seam.
Gluing. Mitered strips should be assembled into sections as soon after planing as possible for varying humidity tends to warp the thin pieces. If nodes were staggered according to the spiral method, assemble the individual strips in proper sequence. Take one or two turns of cellophane or masking tape about the large end. Mix glue according to instructions, Insert a knife blade in a seam between two strips, cutting through the binding tape. Spread the splines flat on a clean board or table, planed surfaces uppermost. Using a stiff brush, spread glue thoroughly over all surfaces to be joined, being careful to cover them completely and to work the glue well into the wood. Pick up the wet splines (still held together by the tape at the ends) and "roll" the large end closed with the fingers.
The assembly is then pressure-wound as described earlier. If the section is then laid on a table and rolled backward and forward under a board, it will be made fairly straight. Further straightening can be done by sighting along the stick and straightening by hand those portions that need it. Small deviations may be treated with heat later after the ferrules have been mounted. Hang the section by one end in a warm room (700 F or more) until the glue has cured. Cross windings are later removed by scraping one end loose and pulling them free.
Sanding. The outer bamboo surface up to this point has not been touched except at nodes. The grainless outer surface must now be removed. A sandpaper block (grade 2/0) or a scraper may be used for this purpose. In either case considerable care must be exercised that only the outer layers are removed without cutting into the underlying fiber structure of the bamboo. As the top surface is taken away, a second, softer, grainless strata is encountered. Beneath this second layer is found the working fiber.
As soon as the grain pattern can be distinguished, work is directed along the surface until the entire side is finished. Repeat the operation on the remaining sides. Do not attempt to flatten out the curve of the original culm; preserve this natural configuration. Finally, clean up all sides with grade 4/0 sandpaper, making strokes with the block along the rod.
The rod section is now ready for ferrule installation, details of which have been given earlier under the heading: Ferrules.
Final Straightening. The various sections are straightened separately. If the rod section is "aimed" slightly below a light, crooked regions are immediately evident. Consider first those nearest the eye. Slide one hand along the shaft to find the exact location of the flaw. Heat the area (and an inch or so on either side) over an alcohol lamp, keeping the rod in constant motion. When quite warm to the touch, aim the section at the light and bend it straight. Repeat until overall straightness is obtained.
Heat with caution at the small end of the tip section lest it be charred. The butt section is straightened in the same manner. Scribe a pencil mark on one side of the butt section near the female ferrule, assemble the rod and then sight along it, scrutinizing the region of the ferrule in particular. Disjoint the sections, rotate the tip section half a turn, and reassemble. If the alignment is better or worse than at first, both sections need treatment near the ferrule. If the degree of deflection is unchanged and casts off in the same direction as in the first instance, then only the butt section is at fault. And finally, if on being reversed the tip casts off in the opposite direction, it is the tip that must be corrected. Not many rods pass this reversing test with perfect scores. From any other than an aesthetic standpoint, absolute straightness is not a practical criterion, nor is it to be construed as measure of performance
ASSEMBLING THE ROD
Once finished sections are on and ferrules mounted, the difficult work is done. Regardless of the material of which the shafts are made, the assembly of grip and reel seat, installation of guides, winding, etc., are similar.
Screw-Locking Reel Seats. Reel seats of the screw-locking type, such as used on plug casting and certain types of fly rod, must be mounted first. A core, usually of cork, is glued to the butt section at the desired reel location. This is then shaped to properly receive the reel seat at one end and the hood (which fits over the reel mounting pad) at the other. Once these are in place, the remaining cork rings are assembled, coated with glue and pressed in place to form the handle (and fore grip in the case of casting rods). The glue is allowed to dry for a day or two. The final handle profile is then turned or shaped by hand to suit one's individual needs.
Cork Reel Seat. If the rod is to be fitted with a cork reel seat and plain band, all cork may be assembled at once. The reel seat portion is shaped to fit securely into the hooded butt cap, followed by grip profiling. The ring is then assembled and the butt cap cemented fast.
Spinning Rod Handles. Spinning handles are made somewhat differently as the large reel bands must necessarily be assembled after the handle is formed. The first three corks are not be glued (sic) they are merely assembled in place. These are removed before the cork is fashioned. Once shaped, the reel bands are slipped over the handle, and the loose cork rings are glued in place and blended into the general form of handle. Many variations of handle exist, the reader probably having his own preference, so that recommendations will not be made here.
Tip Top. Mount the tip top next. Corners of the tip end of the rod may be carefully scraped away or filed to provide a good fit into the mounting sleeve, whereupon the tip top is cemented in place in proper alignment with the cut-out on the screw-type seat if such is present.
Line Guides. Line guides are then mounted. The number of guides used differs
somewhat according to type of rod in question. The table following will then
represent a full complement:
The distance from tip to the next guide on all fly rods should measure about 4-5"; spinning and casting rods, 5-6". Fly and casting rod butt guides are to be placed 24- 30" from the reel location. Spinning rods are somewhat more sensitive, due to line slap. A position 26" ahead of the reel is suggested as a trial location. Tape the large gathering guide in place, then make a few trial casts. Change the position an inch or so at a time until the line shoots cleanly through.
Guides are never spaced equally, but are placed at slightly decreasing intervals toward the tip. This disposition keeps the line close to the shaft in the region of maximum bending.
Winding and varnishing are described in detail elsewhere. When the coat of varnish has dried, your rod is ready for use. In common with the first fly you tied, or the first time you drove an automobile, the results will be considerably short of perfection. Yet you will have created something with your own brain and hands according to a preconceived plan. The memory of the first trip to lake, stream, or river with your rod will likely never be forgotten. In addition, you will be honestly critical of your work.
Then, when splitting out stock for the next assault against angles, flanks, and
diameters, a background of experience plus a knowledge of what not to do will be
your most valuable asset toward building better rods.
See also Modern Bait Casting Rods~ Under BAIT CASTING, FERRULE, GUIDE (2), and ROD. L. Feirabend