"Larry L" schrieb im Newsbeitrag
...
Frog's Fanny is, imho, a great boon to the flat water fly fisher ( not so
flat, too ), but it is pricey.

I oscillate between wanting to support whoever is packaging it, because
they
have improved my fishing and deserve support .... and wanting to find the
same stuff cheaper

I vaguely remember ( about the only type of remember I experience at my
age ) seeing something, somewhere, about the same material packaged for a
different market .... I'm not the least sure it was on ROFF, but if you
know
of a different way to obtain this cool stuff ...let me know, please .....
and thank you, in advance



This is basically a powdered desiccant. The following might be of help to
you;


Silica gel is an amorphous form of silicon dioxide, which is synthetically
produced in the form of hard irregular granules (having the appearance of
crystals) or hard irregular beads. A microporous structure of interlocking
cavities gives a very high surface area (800 square meters per gram). It is
this structure that makes silica gel a high capacity desiccant. Water
molecules adhere to the gels surface because it exhibits a lower vapour
pressure than the surrounding air.

When an equilibrium of equal pressure is reached, no more adsorption occurs.
Thus the higher the humidity of the surrounding air, the greater the amount
of water that is adsorbed before equilibrium is reached. It is in these
higher humidity conditions (above 50% Relative Humidity) that stored or
in-transit items are susceptible to damage.

The beauty of silica gel is the physical adsorption of water vapour into its
internal pores. There is no chemical reaction, no by-products or side
effects. Even when saturated with water vapour, silica gel still has the
appearance of a dry product, its shape unchanged.

Advantages of silica gel as a desiccant.

Silica gel has many other properties that recommend it as a desiccant.

- It will adsorb up to one third of its own weight in water vapour. This
adsorption efficiency is approximately 35% greater that typical desiccant
clays, making silica gel the preferred choice where weight or efficiency are
important factors.
- It has an almost indefinite shelf life if stored in airtight conditions.
- It can be regenerated and reused if required. Gently heating silica gel
will drive off the adsorbed moisture and leave it ready for reuse.
- It is a very inert material, it will not normally attack or corrode other
materials and with the exception of strong alkalis and hydrofluoric acid is
itself resistant to attack.
- It is non-toxic and non-flammable.
- It is most frequently and conveniently used packed in a breathable sachet
or bag. These are available in a wide range of sizes suitable for use with a
wide range of applications.

Standard white silica gel is referred to as being non-indicating. As it
adsorbs moisture it remains physically unchanged. Non-indicating silica gel
is both cheap and effective, available loose in bulk packs or packed in
sachets.

Self-indicating silica gels are coloured gels whose colour changes as they
adsorb moisture.


Silica gel, is often used in the packing of electronic equipment and
similar to prevent damage by condensation. It is usually in small paper
sachets in the packing boxes. If you ask at an electrical goods store or
similar they may be able to give you a whole load of it, as they just throw
it away.

Silica gel is in the form of small spheres usually, to use this as a fly
drying medium, just grind these up in a coffee grinder or similar, you can
also crush it with a hammer, and put in an airtight container such as a 35mm
film can. To dry your fly, just dip it in the powder and shake, the fly is
dry almost immediately.

It is not a good idea to use silica gel in fly-boxes, because the gel will
adsorb water from the surroundings, and may have the reverse effect to the
one desired, holding moisture in your box. The best policy is to ensure
your flies are perfectly dry before putting them back in the box. The best
way to do this is to get a small plastic film canister with a snap on lid.
Drill a series of holes with a small drill around the base, and around the
upper rim. Drill a hole in the lid, pass a cord through it and knot it, and
attach the other end to your vest or whatever. Used flies placed in this box
dry perfectly, and relatively quickly. You cannot lose the flies ( flies
tend to fall out of "drying-patches" and the like, especially barbless ones
! ), and your drying box may be emptied at the end of the day and the dry
flies returned to the main box. This is the best way to dry flies I have
yet discovered.

Goose grease, bacon fat, lard ( rendered beef fat), suet, ( rendered kidney
fat), and a host of other things will work as floatants. Palm oil (
cocoanut oil), which is sold in solid white blocks for cooking purposes, is
also an excellent natural floatant. One old guy I used to know in Yorkshire
dipped his dry flies in hot bacon fat, patted them dry on a soft cloth, and
used them quite successfully.

Preen gland oil from ducks ( although it has never been quite clear to me
how this is obtained) is an excellent floatant. ( Perhaps there are whole
tribes of "duck-milkers" wandering around? ).

Some newer chemical treatments actually repel water.

Silica gel, and some other drying crystals work well without floatants of
any kind.

Nowadays, one has even more problems with floatant, as it is unlikely that
you will find a river anywhere which is not contaminated with detergent.
This causes even tenacious floatants to be washed off very quickly indeed.

There are several principles involved here. The main aim of the exercise is
to prevent the flies getting wet. This may be achieved in several ways. The
most common one is to coat the fly with a substance which is immiscible with
water. But without clogging the hackles etc. Many oils work, but wash off
too quickly. Some thicker oils clog the hackles.

As soon as the hackle tips get wet, they start to penetrate the surface
film, and this accelerates the wetting process further, and eventually the
fly goes under. As we have quite a few fairly new subscribers here, it is
perhaps just as well to repeat another point. There is no point applying
floatant to a wet fly. It will sink. The fly is already wet, and applying
"floatant" to it will avail you nothing. Your only recourse is to dry it
carefully, and then re-apply floatant.

There is no floatant extant which will provide a fly with positive buoyancy.
If you read advertising blurb about floatant which says "Your flies float
like corks", then this is pure hyperbole, They are physically incapable of
doing anything of the sort, irrespective of whatever is plastered on them.

The only flies which float like corks, are made of cork, or similar
material, and in this case do not require floatant anyway.

One of the main reasons that top quality dry fly hackles were prized by
anglers, is the fact that these will stay afloat for quite a while without
any treatment at all. Hardly anybody tries this nowadays, but it works
exceedingly well. It requires a little more false casting to keep the
hackles dry, and a well slimed fly ( fish slime is probably one of the best
"sinkants" available), needs to be washed and dried before re-use. But it
works very well.

Quite a few people used thinned down varnish. This also stiffens hackles
somewhat, but can cause a terrible mess.

The first person to invent an intrinsically waterproof hackle will make a
fortune. It surprises me that firms like Hoffman etc, have not apparently
done much research in this area. It ought to be possible to breed a bird
whose hackles are more waterproof.

Adding scent to flies is not difficult. All sorts of things are now
available which would allow one to do this, and I have no doubt that some
people already do it. It rather defeats the object of fly-fishing though,
which is to fool a fish by presenting him with a lifelike visual copy of
whatever he happens to be feeding on. Adding scent to flies, brings in new
dimensions, which many will not agree with.

It may well be that a fish would take even a completely incorrect copy of a
fly, simply because it smelled good. This again, defeats much of the
objective for many.

TL
MC