For those who nail knot a butt section to fly line, this works for some applications.

I was on a fly fishing charter targeting yellowfin tuna many years ago. Several of the other anglers on the trip insisted their nail knot connections were sufficient. This was their first Bluewater experience. Every single one of those anglers had the same experience. Those connections stripped right off the end if the line leaving some of the exposed core.

I have been using the same connections described on Dan Blanton's site, and the similar connection described on Trey Combs Bluewater Fly Fishing book for 20 years now and never had a failure of a braided loop that I made myself. I have replaced a couple that were damaged by coral, or barnacles also caused complete
Failure of the leader, but the damaged braid still held.


The loops are secured to the flyline with a trap nail knot at the end of the braid where the line enters and the knot then coated with a bit of pliobond. This coating only serves to protect the knot a it and help it go through the guides. I have had fly lines break before the loop. The glued single catch loops available from most commercial sources are prone to failure in the glued sections which do not flex well. The use of tubing is problematic too - a line under tension stretches and when it does its cross section decreases - so the tubing may loosen.

Many of today's flylines have excellent strong loops built into the line but I still use braided loops when I need to replace these.