20# - 30# backing [Archive] - Fly Fishing Forum

: 20# - 30# backing


jarie
03-18-2005, 05:47 PM
There's been lots of talk on the relative merits on the breaking strength of fly reel backing and whether to use 20# test or 30# test. What I wonder from the group is whether anyone has had 20# dacron or micron backing break because of the size or strength of a fish. I'm refering to new, fresh line, not old and possibly weakened with age. I can't get rid of the notion that if you hooked a very large fish that started going south and you had 20# dacron/micron backing, that a knot will fail before 20# backing will just snap in two. Any opinions or insight here.

Penguin
03-18-2005, 08:08 PM
...the only thing between me and my favourite Airflo intermediate going south along with a fish of a life time...
I'll stick with the 30#...

Fred Krow
03-18-2005, 09:55 PM
There's been lots of talk on the relative merits on the breaking strength of fly reel backing and whether to use 20# test or 30# test. What I wonder from the group is whether anyone has had 20# dacron or micron backing break because of the size or strength of a fish. I'm refering to new, fresh line, not old and possibly weakened with age. I can't get rid of the notion that if you hooked a very large fish that started going south and you had 20# dacron/micron backing, that a knot will fail before 20# backing will just snap in two. Any opinions or insight here.

___________________

The main issue between 20# and 30# (Cortland Micron) backing is not the breaking strength, it is the durability of the braid. If you break one of the fibers in the 20# which usually has about 20 strands in the weave, it is much weaker than 1/20 loss of strenght, it will be approximately half strenght. The 30# will have about 24 strands and one breaking will not significantly effect the overall breaking strenght. This is illogical however, it is how the braid is constructed.

The 20# is much more sensitive to wear in the guides and will break down very quickly in comparison to the 30# which is much longer lasting.

Regards,
Fred Krow

flytyer
03-18-2005, 11:44 PM
My trout reels are all loaded with 20# and my steelhead and spey reels are all loaded with 30#. The size of the fish you are fishing for and the abuse the backing will take from a fish should dictate which size. For trout, 20# is more than enough, unless you happen to be fishing where 20# searun browns are common.

Slinger
03-19-2005, 09:20 AM
Stupid of me but I allmost never think about my backing till an Albie has a hundred yds of it out. How long is 20# dacron good for? Mine could be 5 or 6 yrs old by now.
Slinger

zugbugz
03-20-2005, 12:17 AM
Jarie, anything that can happen, usually will...sure a knot might break before the backing does...but as another mentioned, the heavier backing could be the difference between losing an expensive line and the fish of a lifetime...or not. Sure, the knot weakens the backing, but the heavier backing will have a lot more strength at the knot than the lighter stuff. Think of the backing as insurance. Sure, 20 lb backing is plenty strong and for most trout, bass or "light" inshore fishing. Even 12 lb backing is fine for most trout fishing. The rule of thumb is to use backing that is a good bit stronger than the "weakest link" in the chain...the leader. I'm sure you would rather lose the leader and fly than the line (unless you're looking for an excuse to buy a new one!). Try to break even 12 lb backing with your hands and you'll see it's quite strong with a steady (static) pull on it...but try a sudden pull (using a pair of pliers or equivalent) and the outcome will most likely be different. That's exactly what going on with a big, hard charging fish. They don't play by the steady, predictable rules...if you're going for the big boys, go for the 30 lb...just make sure your reel will hold at least 150 yds of it if you're in the salt. :biggrin:

Zugbugz