I also always thought that water migrated into the end of a fly line until I met Leon Chandler, who spent 51 at Cortland Line Company and retired as Vice President. I met him on the Missouri River at Craig. He was spending an entire summer there in his camper, fishing from a personal watercraft.
Leon Chandler: a fly fishing gentleman and unassuming expert | Warwick Beacon
"Leon Chander and the Cortland Line Company - Fly Angler's Online - #219
I asked him about the water migrating into a fly line and he told me that Cortland did experiments, submerging fly line in water and found that there was very minimal water at the very end of the fly line core. It cannot sink the fly line.
I gave this some thought and concluded that for water to enter the core of a fly line it has to displace the air in the spaces between material comprising the woven core. Where does that air go? It cannot go escape since any water in the core would act as a plug keeping the air from leaking out. The air must stay in the core so any a small amount of water enters, the remaining air in the core keeps additional water from entering.
Can't the air migrate to the other end of the fly line attached to the backing and leak out? I suspect the knot tying the backing to the fly line compressed the fly line including the core prevents his. Plus for air to migrate, the water must be under some pressure to push the air through 90 feet of fly line, which it is not.
Secondly, for something entering the core of a fly line to cause it to sink, it must have a specific gravity greater than water. It must be heavier than water. Since water cannot be heavier than water, water cannot make floating fly line sink in water! Since the water does displaces a bit of air, it can make the fly line FLOAT LOWER but cannot sink the line.
Dirt and grime on the fly line coating makes it sink.
When a fly line develops cracks, the water does get into the core and since there are many cracks, the air can escape and be replaced by water. But in a fly line with no cracks, the air in the woven core prevents water from entering.
When the tip of a fly line starts to sink, it is not water in the fly line, it is dirt and loss of the hydrophobic coating.
”In normal use, even on clean water, microscopic particles of dirt and debris will adhere to the surface of a floating line, adding weight that may eventually overcome the natural buoyancy built into the line itself. Because it contains a thinner coating of the buoyant finishing material than does the larger diameter body, the tip section of a tapered line will begin sinking first - an indication that it should be cleaned.”
Take Care Of Your Fly Line - For Beginners - 101, FAOL
From the day I met Leon, I have never sealed the end of fly lines. However, I think most people do and do it if it gives you confidence. I do not and have not had a problem.
I use both the braided nylon loops connectors and also nail knotted Maxima Cameleon. Both work. I have not had a problem with the braided loops coming off. I throw away the plastic sleeve and use a whip finish and then coat with my flexible UV resin but thinned Aquaseal will also work. Salt water certainly needs a stronger connection but for trout, I think the braided loops are fine.
