A Perfection Loop knot is pretty weak, about 60% of line test strength as I recall. Surgeons loops are supposed to be a lot stronger. The ones I tie break way too easy, so I must not do them right. But that's a separate matter.I see that everyone who is using a loop to loop is using a double or triple surgeons loop, why not a perfection loop?
That's me. I had one of those factory loops fail and got to watch an $80 full sinking line go through the guides and into the Skagit River.I'd snip it off and tie an albright knot to connect the backing to the fly line.
Yeah, if your line is like a Rio In-Touch or any brand that has some sort of core material like mono or dacron then it's not going to break. At least not in reasonable situations. Now if it's an older line or just one that doesn't have a core then you may not want to trust the loop. Especially for heavier stuff like 7wt and above.For the record even the GT guides in the Seychelles no longer recommend cutting off the factory loops (which I haven't done for years and have never had one fail although I do know guys who have had a failure). The technology has improved to the point where you don't need to worry about it.
All my Dacron backing connections get a reverse blind splice. Stronger than the backing rating, knotless and thin.
It takes a little bit of patience at first but HIGHLY recommended. Use brassie or small wire instead of piano wire