Fly Line DIY Repair: Replacing a Welded Loop

The line pictured above has served me well but it has seen one too many applications of super glue and Aquaseal and is in need of a serious repair.

Modern fly lines often come with a welded loop that allows an angler to quickly switch out leaders with a loop to loop connection. This process is significantly faster than attaching your leader to your fly line via a nail knot. Unfortunately, over time dirt, sun, salt, bug spray, and sunscreen can all have degrading effects on a fly line and the welded loop regardless of how much time and care you put into maintaining your line. The welded loop on a fly line is often the first point of failure as it receives a bulk of the stress applied to the line when you’re hooked up with a fish. Have no fear, you can easily repair your fly line (even on the water) with the tips and materials below.

Required Materials:

  • Damaged Fly Line
  • Knife/Razor Blade
  • Aquaseal (Optional)
  • Superglue (Optional)
  • 2/32″ Heat-Shrink Tubing (approx 1”)
  • Lighter/Heatgun

Removing the Failed Welded Loop

The core on most coldwater fly lines is a braided material similar to backing. Once the exterior fly line coating has worn away, your line will begin to absorb water and sink which can be catastrophic if you are fishing a floating line. These steps should help you extend your day on the water if not the life of your line for many trips to come.

The line pictured above has served me well but it has seen one too many applications of super glue and Aquaseal and is in need of a serious repair.
  1. The first step in repairing your fly line is to remove the failed welded loop and any additional fly line that may be cracked or damaged.

Tip: Once you have cut off the old loop and damaged line, place a drop of Aquaseal on the exposed end of your fly line core to prevent it from absorbing water.

Creating a new Welded Loop

  1. Once you have removed the damaged line, double over the line (approx. ½” of overlap) to create a new loop. Placing a drop of superglue on the line will help maintain the correct position of the loop while you work.
Using superglue isn’t required but it helps ensure a clean end result.

2. Next, cut a ½” long piece of 2/32” diameter heat-shrink tubing.

I used the smallest size heat shrink tubing in this package,2/32″.

3. Slide the ½” piece of heat shrink tubing over the new loop that you have created extending past the doubled-over line.

Tip: To avoid avoiding burning your fly line, wrap the exposed line and new loop in aluminum foil before applying heat.

A heat gun is ideal but a lighter works just as well.

5. Apply heat until the tubing adheres to your doubled-over fly line. Note, there’s no need to touch the tubing with the flame.

The end result after gently applying heat with a lighter.

Stress Test

Like any knot, be sure to strength test the work that you have done. It’s much better to uncover shoddy workmanship now than when you have the fish of your dreams on the line.

Repairing your line is a way to extend your day, trip, and life of your fly line.  The method shown above is great for on the spot repairs. You can easily carry a piece of heat shrink tubing and a lighter in your vest or pack. There are other methods of repair involving whip finishing a new loop with epoxy which may be a better long term solution and for chasing large fish, however, this method has yet to fail me in pursuit of trout. As previously mentioned, regardless of how well you take care of your line, it will eventually crack with time, sun exposure, and abuse. Hitting the water with a fresh line is always the best choice when your line is showing signs of use but this DIY trick should help extend the life of the line you already own. 

Article by Evan Garda, he is on the Content Team here at Fly Lords. He can be found chasing trout throughout the west with his trusty fly rod. Check out his adventures at @evangarda.

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