Add or replace a loop on the end of your fly line you want to do. A new product out that will help you do this called Restorline ReLoop https://anglersall.com/products/restorline-reloop?srsltid=AfmBOoqa7cYZRU7VgxA_Wa1JTk3VGy092xrXgccDRccAOoPCXqMwWVoX
If you don’t want to do this then:
Backing to fly line – try an Albright knot if no welded loop or a good tube (nail) knot will do.
Fly line to leader material – if no welded loop then try a nail knot by using a butt section of a leader but best for saltwater (12wt rod) to use hard mono with a diameter that is close to the fly line diameter to start. With a tube/nail knot you can make a loop and then add any bought leader material to it with a loop to loop.
A welded loop IS strong enough to do a loop to loop connection so DO NOT cut any fly line welded loop off – use it. To cast 12 wt line and for big fish you may need hard mono to build your leader (if you can afford to do it – jump on a slow boat to china and come to my palace for materials.)
If loop to loop were a weak spot then fly line companies would not add them. Check out the latest podcast on Orvis Fly Fishing Podcast, September 14th to “geek out” on leaders.
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