Purpose of the knot?
To attach two lines together – in most lure fishing scenarios this refers to tying a braided mainline to a fluorocarbon leader.
We use fluorocarbon leaders for two main reasons when lure fishing. Firstly, braid, although remarkably strong, is not very abrasion friendly. The woven composition is susceptible to fray when it comes in to contact with rocks and boulders. To overcome this we use a fluorocarbon leader – similar to mono but stiffer and more resilient against rough edges. The fluorocarbon then acts as a rubbing leader between the braided mainline and the lure.
Secondly, fluorocarbon is theoretically invisible to fish. Many lure anglers prefer brightly coloured braided mainlines for ease of sight. Using a length fluorocarbon as a leader decreases the chance of fish seeing the braid and being spooked.
How to tie it?
Take the fluorocarbon and create a loop in the end, leaving an inch or two of a tag end. Ensure the tag end is parallel with the main piece of leader. Feed the braid up through the loop and make 7 consecutive tight wraps down the fluorocarbon mainline and tag end.
Now make 7 consecutive tight wraps back over the previous 7 until you reach the loop at the end of the fluorocarbon.
Feed the braid down through the loop. Slowly pull all 4 ends and gently form the knot. Then release the tag ends and pull both mainlines to tighten and complete the finished knot. Trim the two tag ends as close to the formed knot as possible.