Mike S. wrote:
I bought a Shimano Spirex last summer and was so satisfied with it I bought
another one about 2 weeks later. After contacting Berkley concerning
problems with their fireline on my baitcaster they sent me info on fireline
and their Vanish Florocarbon line. I'm cut and pasted it below.
Mike
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What is Fluorocarbon? Fluorocarbon is a polymer consisting of fluorine, a
common element that is chemically bonded with carbon, another common
element, to create a polymer that can be formed by molding, extrusion or
other heat processes.

Fluorocarbon has unique properties that make it ideal for specific
applications.

. It is inert, so it resists deterioration by most chemical means, such as
sunlight, gasoline, battery acid or DEET (common ingredient found in insect
repellents).

. A density of 1.6, meaning it is heavier than water and sinks, and is tough
against rocks, docks, etc.

. A refractive index (an indication of the degree at which light refracts or
bends as it passes through a substance) of 1.42 - almost the same as water.

. Non-absorbing, meaning it will not absorb water.

Why a fluorocarbon fishing line? Fluorocarbon fishing leaders originated in
Japan, where the Japanese are extremely detailed about the presentation of
their bait. The Japanese fish under heavy pressured conditions and make
every attempt to make their presentations as real and lifelike as possible.
They pride themselves on their ability to do this, and willingly spend more
money to do so.

Fluorocarbon manufacturers claim that fluorocarbon is virtually

invisible due to the refractive index being nearly equal to the refractive
index of water (1.3). It also has a very clear appearance. Naturally, the
Japanese were intrigued with fluorocarbon line and it became very popular.

Ultimately, U.S. anglers began using fluorocarbon leaders, primarily in
sal****er and fly fishing applications, for the same reason the Japanese
were using it - low visibility. It caught on when anglers reported catching
more fish with it. However, leaders are stiff and very expensive. Now,
application of fishing line technologies has produced more flexible
fluorocarbon at affordable prices.

Is fluorocarbon invisible to fish? This question has not been scientifically
or empirically answered. Berkley scientists tried to somehow quantify this
with an experiment in the Berkley® Fish Lab. Strands of monofilament were
hung in a tank where bass swam freely, each line connected to a sensor that
counted the number of times a fish hit, or bumped into it. The theory was
that fish will avoid objects they can see. The results indicate that fish
could see nylon monofilament better than they could see fluorocarbon.

When is fluorocarbon fishing line better than nylon? It depends.
Fluorocarbon certainly would offer the best advantage in clear water
situations where fish are heavily pressured or slow to bite - finesse
situations. Anglers believe this is true based on experience. However,
fluorocarbon offers other advantages that have been overlooked, making it an
excellent fishing line for other situations and conditions.

. Excellent wet strength - because fluorocarbon does not absorb water, it
will not weaken or increase in stretch like nylon fishing lines will. In
fact, Berkley VanishT is stronger than wet Trilene® XL and XT, or Original
Stren® and most other nylon fishing lines.

. Excellent durability - the added density makes fluorocarbon very
abrasion-resistant, making it ideal for fishing in rough conditions such as
logs, rocks and docks.

. Extra density - fluorocarbon sinks, which will enable lures to dive deeper
and faster than nylon fishing lines.

. Stretch resistance - fluorocarbon stretches slower and less than nylon,
particularly when compared to wet nylon, making it much more sensitive.

What should anglers watch out for with Vanish? There are several "inherent
properties" of fluorocarbon that require special attention for anglers to
fish Vanish successfully.

1. Knots - The Trilene Knot has been found to effectively tie the most
consistent and strongest knot. Make all five wraps when tying the knot, and
excessively wet the line before cinching the knot to prevent heat from
building up and weakening the line. Always test the knot before

fishing.

2. Stiffness and Coils - As castable as Vanish is for a

fluorocarbon, all fluorocarbons are still stiffer than nylon, even when wet.
This requires more attentiveness to the line when casting, and finer
"balance" of tackle. If heavier Vanish line is used on lighter rods, reels
and lures, anglers will experience more difficulty. The following is

recommended when selecting Vanish for various reels.

Spinning Reels, sizes 1-4: up to 8-lb. Vanish

Spinning Reels, sizes 5-9: 10 to 14-lb. Vanish

Spincast Reels: up to 12-lb. Vanish

Baitcast Reels: all sizes Vanish

Do not overfill reels! Fill to 1/8" from spool rim.

3. Casting with Baitcast Reels - baitcast reels may require additional
adjustment for the extra momentum created by the heavier weight of Vanish.
Adjust the mechanical brake to the weight of the line and lure for maximum
casting distance and minimal tendency to overrun.

Thanks Mike for this reply. Very good read.

I've been using Berkley's Vanish and Trans for a while now. I so far
have had no problems with it, other than the gold color on the T line
does seem to fade after awhile. I always tie a
Trilene Knot , so I haven't experienced the problems other anglers have
with the line breaking at the knot.

I've read and heard many anglers who don't use fluorocarbon because of
casting and breakage. But, truth be told; these are most all anglers
who tie the wrong knot and use wrong sizes with the application of reel
used. Fine with me. I thank those anglers, it gives me an edge and
helps drop the cost of the product.