Welded Loop Fly Line Test: Can You Trust the Manufacturer's Loop?

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Episode Show Notes

A welded loop is the manufacturer's pre-made loop on the end of a fly line that you use for a loop-to-loop connection to your leader, and many fly fishermen simply do not trust it. On this How 2 Tuesday I test the welded loop on a brand-new fly line to settle whether you should trust it. The question is the strongest connection between fly line and leader, and whether that factory loop is up to the job.

Listen now: press play in the player above and follow along.

Frequently Asked Questions

How strong is a welded loop on a fly line?

On the fly line I tested, a brand-new Cortland, the manufacturer's welded loop broke at 46.97 pounds. The important thing is that the welded loop was not fatigued at all, it actually broke down in the fly line itself. So on this particular line the loop is stronger than the line, which means you can have real confidence in it.

Can you trust the manufacturer's welded loop?

Yes, based on this test you can feel confident with the welded loops. Unless you are using 100-pound test for tarpon, if you are fishing 12, 16, 20, even 30 or 40-pound class tippet, the fly line is going to be stronger than any part of your leader. So the welded loop is not going to be your weak point. The connection holds.

Why do some fly fishermen distrust welded loops?

Many fly fishermen who have been at it a long time simply do not trust the manufacturer's loop. A lot of people have never actually tested one, so they do not know how strong it is, and they assume the factory loop is the weak link. Testing it is exactly why I did this episode, to replace that assumption with a real number.

What is a loop-to-loop connection?

A loop-to-loop is a very popular way to attach your fly line to your leader. You use the welded or manufactured loop on the fly line, then tie a double overhand loop or a surgeon's loop in the butt section of the leader, and connect the two loops together. You want the strongest connection that also passes smoothly through the guides.

Do all fly lines have the same loop strength?

Not necessarily. One thing about fly lines is that nowhere on the line does it state the strength of the core, so that can differ from line to line. I tested a Cortland here and found the loop stronger than the line, but I will be testing a lot of different fly lines, because core strength varies and that affects where the connection breaks.

Where can I see how this compares to other connections?

I test fly line and leader connections across this series, and I keep a free knot guide at tomrowlandpodcast.com with the breaking strengths and videos for everything I have tied and tested. It lets you compare the welded loop to other ways of joining your fly line and leader so you can pick what you trust.

Why I Tested the Welded Loop

It is fly season and a lot of people are rigging up right now, and the loop-to-loop with a manufacturer's welded loop is one of the most popular connections out there. Plenty of experienced fly fishermen just do not trust it, and most have never tested one. I get into why that matters in the episode, so press play in the player above.

How to Connect Fly Line to Leader with a Welded Loop

  1. Use the welded loop on the fly line. Start with the manufacturer's welded loop on the end of your fly line, like the one on a new Cortland.
  2. Tie a loop in the leader butt. Tie a double overhand loop or a surgeon's loop in the butt section of your leader.
  3. Make the loop-to-loop connection. Connect the two loops together for a clean loop-to-loop join between fly line and leader.
  4. Check it runs smoothly. Make sure the connection passes smoothly through the guides so it does not hang up on the cast or the fight.
  5. Match it to your tippet. Trust the welded loop for 12 to 40-pound class tippet, since the fly line will be stronger than the leader.

I walk through each of these in the episode. Press play in the player above.

What the 46.97 Pounds Tells You

The welded loop on the new Cortland broke at 46.97 pounds, and it was not fatigued at all, it broke down in the fly line. So on this line the loop is stronger than the line itself. For anything short of 100-pound tarpon setups, that is more than enough. I break it down in the episode, so press play in the player above.

Why Fly Line Cores Are a Mystery

Here is the catch: nowhere on a fly line does it tell you the strength of the core, so it varies from line to line. That is why I will keep testing different fly lines rather than assuming one result covers them all. I explain what to watch for in the episode, so press play in the player above.

Final Thoughts From Me

On this Cortland, the welded loop is stronger than the line, so you can rig your loop-to-loop with confidence for normal tippet classes.

Just remember core strength is not printed on the line, so I will keep testing more of them. Grab the free knot guide at tomrowlandpodcast.com to compare connections. Press play in the player above.

More How 2 Tuesday Tutorials

How 2 Tuesday is my weekly series where I break down one fishing skill at a time, from knots and casting to gear, tactics, and the habits that make you a better angler. Watch and listen to every How 2 Tuesday episode from Tom Rowland.

People & Topics Mentioned

Welded loop · fly line · loop-to-loop connection · Cortland · leader · surgeon's loop · double overhand loop · tarpon · tippet · Danco pliers · How 2 Tuesday · Saltwater Experience

About Me

I'm Tom Rowland, a professional fishing guide based in the Florida Keys, host of the Tom Rowland Podcast, and the longtime host of the Saltwater Experience television show. On the podcast's How 2 Tuesday series I break down one practical skill or lesson at a time, from fishing technique and gear to the habits that make you a better angler, in short, focused episodes you can put to use right away.

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