weight

When fishing nymphs, effective presentation most often involves getting into and maintaining a drift in the benthic food lanes just above the streambed.  Several factors enter in here, including casting (mastering the tuck cast) to get the flies down early in the drift; leading and managing drift in the benthic currents (see the excellent discussion in  George Daniels’ Dynamic Nymphing); keeping dressing bulk low to maximize sink rate; tippet selection; materials selection to minimize buoyant and air-trapping dressings; and weighting of the flies.

Several options exist for weighting flies  (I do need to admit that, having watched Midsomer Murders season 6 episode 1, I write this with some trepidation … ). Weighting leader or tippet with split shot or Loon tungsten putty is certainly one option, as is using such weight or a heavy “sacrificial” fly on point with flies above, on dropper (“bounce nymphing“).  I’ll occasionally use a bit of Loon “deep-soft weight” tungsten putty on the tippet, but usually prefer to have my weight in the fly itself.  Brassies, Copper Johns and the traditional Sawyer pheasant tail nymph, e.g., rely on copper wire bodies or bodies heavily incorporating copper wire in their construction.    Competition rules, for those so inclined, do require that all weight on the hook (other than a single metallic bead) be covered with acceptable dressing, ruling out Brassie and Copper John patterns in the competitive setting.  The body wire of a Brassie or Copper John actually adds little to the weight of the fly, tho this may be more significant on smaller midge patterns. A tightly-wound body of UTC ultra wire sized “brassie”tied on a #14 hook weighs 0.02g, ~1/3 the weight of the hook it is tied on, and considerably less than a tiny 2mm bead.  It is, however, denser than other potential body materials, and contributes a slim body presenting little resistance to sinking.

Lead wire underbodies have been incorporated into many patterns.  Lead has a specific gravity of 11.35, , 27% greater than that of copper (8.89 kg.m3), and is softer so wraps more easily in larger gauges.  The use of square or flat, rather than round, wire permits more even & compact and somewhat reduced underbody bulk, esp. when building up multi-layered underbodies.  Lead, however, is a significant environmental toxin, and its use is banned in many areas.  In the aquatic environment, lead partitions to sediments, with its bioavailability increased by acidity and organic matter.  It is taken up by, and is toxic to, algae and invertebrates (= fish food) and by fish, amphibians and aquatic birds (diving ducks & loons) and has been seen to be a significant cause (up to 30%) of loon mortality in the northeast.  I’ve seen this concern ridiculed, hear it as a personal preference but please research it and consider it seriously rather than scoff at it mindlessly.  I choose to leave any lead I have on the spool or in its original package for use as paperweights, rather than incorporating it into flies many of which will be sacrificed to rocks, downed limbs, overhanging brush, and lost fish and end up potentially contributing to the demise of the streams I love.  A personal choice I will not impose on others, but one which I do not find to be a hardship, and I which would encourage others to consider.  There are of course other and more significant sources of environmental lead (and other) toxins affecting our streams; one’s lost flies might well be a small contributor to this overall.  However I do not feel that avoiding the use of lead has involved any sacrifice on my part, other than the occasional need for creativity at the tying bench and perhaps the cultivation of technique in leading & managing drift, both of which add to my overall success on the stream.  A 3.5 mm tungsten bead as a beadhead or incorporated into the thorax of a Czech nymph weighs more than a full underbody of 0,35″ dia. lead wire on a #12 hook, and totally skirts this issue.

“Non-lead” wires are sold as a non-toxic lead-replacement.  These are made of a malleable tin alloy, which has a specific gravity of 7.31, 36% less than that of lead, and 18% less than that of copper; but these do not tarnish & discolor on exposure as does uncoated copper, and are more malleable than copper in heavier gauge.  When substituted in patterns relying on a  lead underbody the resulting fly will not be as heavy, but with attention to other tying and fishing factors (mentioned above) these may well suffice in use.

Tungsten wire, tho available in finer gauges, is a no-go.  This is brittle and springy rather than malleable, and would be entirely unworkable in heavier gauges.  It can be used for ribbing (contributing negligibly to weight, and awkward even in this application), but cannot really be used effectively for a weighted underbody.  I found a piece of tungsten sheet from Veniards that might have some promise if cut into strips (like flat lead wire) for wrapping; I’ve yet to play with this, but will post my experiences when I do.

Another option is the use of beads, at the head and/or built into the thorax, on a conventional or jig-style hook.  Beads may be made of plastic (sp.grav. 1.2) or glass (sp. grav. 2.5), useful principally incorporated into the thorax of a soft hackle wet fly to fish just below the surface film ; or used primarily decoratively, as in the fabulous Quigley’s Crown Jewel green drake nymph; of brass (sp. grav. ~8.5) for intermediate weight (e.g., in the thorax of Ish Maloney’s March Brown wet fly), or of tungsten (sp. grav. 19.22, 70% greater than that of lead, 126% greater than brass).  The bead can add color and flash to the dressing, as well as weight.  Competition rules (for those so inclined) generally permit a single exposed bead as part of the dressing.  Brass and tungsten beads are available in a wide variety of electroplated and painted colors.

Many patterns add several wraps of lead wire behind and seated into the countersunk recess of a tungsten bead to “secure the bead”.  This does add weight, but is not necessary to actually seat the bead, which is easily accomplished with a few tight wraps of tying thread.

It is possible to use “bead-like” weight either or both at the head & in the thorax of a nymph.  One example of a “depth bomb” incorporating two standard beads is Charlie Craven’s “two-bit hooker”.  Tungsten teardropsjig backs and shrimpbacks (from Hends) provide more weight for a given diameter than do standard beads; teardrops can be paired with standard beads, provided these can be adopted into the pattern.

Understanding that the depth of drift of a fly will depend on many issues in addition to weight (stream conditions, tippet diameter & material, casting technique, leading technique; nature  of fly dressing including buoyancy of other materials & bulk of the dressing), here’s a table of common weighting materials (I use a small digital jewelry scale to weigh my flies & materials; I doubt you’ll find any trout doing the same, but you might use these figures, factored in with those others noted above, to predict the behavior of flies tied with these materials):

slotted 2m tungsten bead0.034gram
slotted 2.5m tungsten bead0.0101g
slotted 3.0mm tungsten bead0.170g
slotted 3.5mm tungsten bead0.307g
slotted 4.0mm tungsten bead0.421g
Hends small slot 2.0mm tungsten bead0.058g
Hends small slot 2.3mm tungsten bead0.115g
Hends small slot 2.8mm tungsten bead0.180g
Hends small slot 3.4mm tungsten bead0.279g
round lead wire, 0.15"dia.005g/turn
round lead wire, 0.20"dia.008g/turn
round lead wire, 0.35"dia.032g/turn
square lead wire, 0.27".018g/turn
flat lead wire, Hends 0.4.015g/turn
flat lead wire, Jan Siman medium.012g/turn
Hends tungsten teardrop 1.4mm0.153g
Hends tungsten teardrop 2.7mm0.205g
Hends tungsten teardrop 3.2mm0.322g

I’ve found that bead weights may vary slightly among manufacturers, but have not been good about segregating my beads by make or source.  Slotted beads – which seat best on the  jig-style hooks I most commonly use – generally weigh slightly more than do countersunk beads, as less metal is cut away for the slot than for the countersink.  I like the faceted (“disco”) beads in gold and silver when going for the additional flash (and would definitely employ these if fishing with John Travolta), but don’t find an advantage in them in the more subdued colors.

I’ve left off the topic of ceramic nymphs, as I have no personal experience with these, nor the personal inclination to explore their use.  They certainly appear to be potential bottom-dredgers for those so inclined, and there are some who apparently find these quite effective.  Looks like they’d sink like a stone.

Sources:

most flytying suppliers will stock a range of beads.
I obtain most of mine from

BlueQill Angler (Colorado)(the 50-bead packs are an excellent deal)

Performance Flies (Pennsylvania)

Tungsten-Beads Plus (UK)(esp. for the Hends small-slot tungsten beads and teardrops)

See my previous posts on bead size & weight for #14 nymphs and bead size & weight for #16/18 nymphs, and look for future posts on tying with weight, including matching bead to hook size and working with glass & plastic beads, tungsten teardrops &c.; as well as a number of already-posted and upcoming patterns incorporating weight.

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