More silk

[Mike Connor]

Good info Mike. Have you done this? Do you recommend one method over another?
A friend of mine is in the process of purchasing a building near the Long Island Sound that once was a fishing net factory. The line-strength testing machine is still there, and my friend has expressed interest in trying it out. If he can make it work, I may be able to out-source this to him, and save myself the trouble. More later.
Lance

I have tried a few methods but to be honest I don't really see much point in doing it at all as far as fly-dressing thread is concerned. Whatever thread you use the main points involved are in actually controlling it and keeping it at the optimal tension. Knowing what that tension is in terms of actual breaking strain doesn't do you much good with tying thread you have to "feel" it while dressing your flies.

Any of the methods described will work fine. There is also a method using a spring scale ( often also called a "balance") with a pointer that stops at the position of maximum deflection (where the thread breaks )which is quite accurate if the scale is well calibrated and tells you the breaking strain directly in ounces or grams or however the balance is calibrated. This is probably the easiest, but depends on the accuracy of the scale.

http://en.wikipedia.org/wiki/Spring_scale

It should be noted that it is impossible to measure a spun, braided, or woven thread or rope etc using calipers or similar. This is intrinsically impossible with multifil threads, it works to an extent with monofil of course assuming that the monofil is evenly round, or evenly flat ( where one would measure in several planes of course).

Scott Sanchez had a large article on a couple of websites ( Fly-fisherman was one), about various threads including the breaking strains, but it seems to have disappeared. Perhaps a search will turn it up?

Here is part of it; http://frontrangeanglers.com/newsletter ... thread.htm

TL
MC

[Mike Connor]

It should also be noted that the breaking strains of various natural materials vary widely, even in material which is apparently identical ( like silk). Condition, age, heat, damp, light deterioration caused by photon strikes especially in the ultra-violet ranges, and other things influence this a lot. Most people wildly overestimate the breaking strains of various tying threads.

TL
MC

[Mike Connor]

With regard to silk it is worthwhile knowing its properties in general. This is all good information and is fairly comprehensive;

http://en.wikipedia.org/wiki/Silk

QUOTE
Physical properties

Silk fibers from the Bombyx mori silkworm have a triangular cross section with rounded corners, 5-10 μm wide. The fibroin-heavy chain is composed mostly of beta-sheets, due to a 59-mer amino acid repeat sequence with some variations.[22] The flat surfaces of the fibrils reflect light at many angles, giving silk a natural shine. The cross-section from other silkworms can vary in shape and diameter: crescent-like for Anaphe and elongated wedge for tussah. Silkworm fibers are naturally extruded from two silkworm glands as a pair of primary filaments (brin), which are stuck together, with sericin proteins that act like glue, to form a bave. Bave diameters for tussah silk can reach 65 μm. See cited reference for cross-sectional SEM photographs.[23]

Silk has a smooth, soft texture that is not slippery, unlike many synthetic fibers.

Silk is one of the strongest natural fibers but loses up to 20% of its strength when wet. It has a good moisture regain of 11%. Its elasticity is moderate to poor: if elongated even a small amount, it remains stretched. It can be weakened if exposed to too much sunlight. It may also be attacked by insects, especially if left dirty.

Silk is a poor conductor of electricity and thus susceptible to static cling.

Unwashed silk chiffon may shrink up to 8% due to a relaxation of the fiber macrostructure, so silk should either be washed prior to garment construction, or dry cleaned. Dry cleaning may still shrink the chiffon up to 4%. Occasionally, this shrinkage can be reversed by a gentle steaming with a press cloth. There is almost no gradual shrinkage nor shrinkage due to molecular-level deformation.

Natural and synthetic silk is known to manifest piezoelectric properties in proteins, probably due to its molecular structure.[24]

Silkworm silk was used as the standard for the denier, a measurement of linear density in fibers. Silkworm silk therefore has a linear density of approximately 1 den, or 1.1 dtex.
Comparison of silk fibers[25] Linear Density(dtex) Diameter (μm) Coeff. Variation
Moth: Bombyx mori 1.17 12.9 24.8%
Spider: Argiope aurentia 0.14 3.57 14.8%

UNQUOTE

TL
MC

[gingerdun]

Mike, as usual, you are a fountain of information. Much appreciated. I had not known that silk was weaker when wet. Regarding your comment:

I have tried a few methods but to be honest I don't really see much point in doing it at all as far as fly-dressing thread is concerned. Whatever thread you use the main points involved are in actually controlling it and keeping it at the optimal tension. Knowing what that tension is in terms of actual breaking strain doesn't do you much good with tying thread you have to "feel" it while dressing your flies.

That was what I had thought too, until I started seeing the growing popularity of the split thread dubbing technique. Not having fished any split-thread flies, I don't know how tough they are compared to, for example, the Leisenring spun body or dubbing loop. The only facts I have are that the Benecchi threads used commonly for split thread technique have about double the breaking strength of Pearsall's silk. Does this then translate into more resistance to gnawing of trout teeth? Does anybody care? The last time I raised the question of durability of the fly during fishing, it seemed to be dismissed as a non-issue these days. So the question of thread strength is perhaps meaningless in terms of today's fishing. I have no answers, only questions.
But, personally, given a choice of two silk threads of comparable thickness, one of which had a higher tensile strength than the other, I'd choose the stronger. That was why I raised the question regarding this new silk thread source.

Lance

[Mike Connor]

Compared to the problems it once caused fly-dressers and anglers it pretty much is a non issue nowadays. If your fly gets torn to bits just tie another one on. This is easy and quick to do, which it once was not. It is also easier and quicker to dress the flies themselves nowadays.

Tensile strength does not translate directly to durability, although it may have a bearing on some things, that depends on other things far harder to determine. Kevlar is very tough indeed for instance, you can barely cut it at all with normal scissors and it does not fray easily either.

Just about the best way to secure a dubbed body is with a good wire rib. Some things are more durable than others, a fully dubbed "noodle" type body is more durable than a split thread body because the silk is protected by the thick dubbing noodle, but the split thread dubbing is invariably more effective in terms of lightness delicacy and translucence, when done properly, with touch dubbing even better.

There is little point in worrying about the durability of most small flies,beyond a certain amount of use, or a few fish, if you catch even one good fish on a small fly then it has done its job, catching more is a bonus.

Naked silk frays comparatively quickly and badly, even just casting it will damage it in time it is a property of the material.

TL
MC

[Mike Connor]

Even my silk bodied soft hackled spiders, with no rib, usually catch quite a few fish before they become ineffective. Personally I prefer a delicate fly that reliably catches half a dozen fish than a more durable fly that lasts a long time but is not as attractive to the fish. It has long been known, and often stated by those who know, that a scruffy sparse fly will rise more fish than a pristine more heavily hackled and durable example fresh from the box. One reason I try hard to make my flies as delicate and sparse as possible to begin with. I see no point in having to wait until my flies look scruffy and sparse before they start catching well.

TL
MC

[gingerdun]

Makes perfect sense, Mike. Thanks for taking the time to state this so clearly.

Lance

[hankaye]

Howdy All;

I'm going to tippy-toe through this minefield ... just want to suggest that;

When a thread with a stronger tensil strength is used the tyer is able to inpart more
tension (torque), to the material being tyed on. This in turn may inpart
somewhat greater defences to the gnawing of stubby teeth wither they be
sharp 'new' teeth from a young trout or the more rounded teeth of an older fish
as there is no softness or 'give' for the teeth to find purchase on/in ....

Only my thoughts, no science behind it. Just what seems to make sense to me...

hank

[Mataura mayfly]

A lot depends on "where" in the mouth the fish is hooked as to if it can get a few good chews in on your tied offering. I find small "excitable" trout tend to shred flies quicker than older larger fish which prefer the strong arm wrestle runs and rubbing you off on a log to jumping and splashing hither and tither short runs in the one pool typical of our smaller trout.
Silk with catch and fray at the slightest of abrasions, but it still lasts better than a wrapped peacock herl body that is not ribbed.

[DNicolson]

Mike is right. The purpose of a fly is to catch fish, most material today - silk, dubbing, tinsel and even hackle is relatively cheap. A couple of hen skins, a few spools of thread, tinsels and several dozen hooks, can supply a lot of flies. To make durability the priority for your flies rather defeats the whole point of tying and using flies. One fly, one fish, is a good return.
And that is from a Scot.