JDM Fishing Knots: FG Knot and ISO Knot Step-by-Step Guide

Every fisho who runs PE braid learns the same lesson, usually the hard way: the strongest line in the world is only as good as the connection joining it to the leader. A kingfish that dusts you on the rocks, a snapper lost in the wash, a $30 stickbait sailing off with the leader still attached — nine times out of ten the failure point is the join, not the line. This FG knot tutorial covers the two line-to-leader fishing knots we get asked about most: the FG knot for joining braided line to fluorocarbon or monofilament leader, and the leader join used in ISO float fishing. You will learn why each one works, the step-by-step method on how to tie it the way Japanese anglers teach it, which tools make it easier, and how to test it before it meets a fish.

Why Braided Line Needs a Leader and a Proper Braid to Leader Knot

PE (polyethylene braid) is the backbone of modern JDM casting, jigging and shore fishing: near-zero stretch, a tiny diameter for its breaking strain, and 300 m of #2 on a reel that would hold a fraction of that in nylon. But it has two weaknesses that make a leader non-negotiable in saltwater. It has almost no abrasion resistance — PE rubbed across a barnacle ledge or a kingfish's gill plate parts quickly — and it is visible and stiff in the water. A clear leader takes the punishment, gives a natural presentation and puts a little stretch back into the system.

The catch is that PE is slick, thin and slippery while leader is thick and hard. Joins that work perfectly for monofilament or fluorocarbon of similar diameter — a blood knot, a uni-to-uni — either slip or leave a bulky lump that catches the guides mid-cast. So Japanese anglers developed friction knots, where the thin line grips the leader by wrapping around it under tension rather than knotting through it. The FG is the best known and the standard PE to leader connection for shore casting, light jigging, GT fishing and stickbaiting across Australia. The Alberto knot and the improved Albright knot are the main alternatives; there are many methods, but the FG is one of the strongest and by far the slimmest.

A good friction join holds close to 100 per cent of the main line's rated strength, flies through the guides on a long cast, and does not slip once set — the best leader-to-line connection for lure fishing. Then you tie the lure on with a loop knot or a Palomar knot, or, if using live bait, a Trilene knot or improved clinch knot to the hook, and go fishing. New to the wider JDM approach? Start with our introduction to ISO fishing for Australian anglers.

The Easiest Way to Tie the FG Knot: Step-by-Step

The FG looks intimidating the first time you see it, but it is really two things: alternating wraps of leader around tensioned PE, then locking hitches. There are several ways to tie it — rod in a holder, line in your teeth, or with a tool — but the mechanics below are the same.

What You Need

• PE main line — a smooth, tightly woven eight-strand casting PE such as the VARIVAS Avani Casting PE Max Power X8 (#1 to #8, 300 m, 25 m markings) bites into the leader cleanly and gives the slimmest finish. See the full casting PE range.
• Leader — fluoro for most casting and jigging work, such as the Varivas Fluorocarbon Shock Leader 30m in #2.5 (10 lb) to #20 (70 lb), or browse the fluorocarbon leader collection; nylon for stickbaiting or where you want more stretch, from the nylon leader collection.
• Sharp PE scissors — ordinary snips or a pair of pliers crush PE fibres and leave a fluffy tag end. A dedicated pair like the Shimano Supa PE Scissor CT-522Q cuts PE, nylon and fluoro cleanly.
• A lighter (optional) — to mushroom the end of the leader.

The Steps

1. Put the PE under tension. Pull off 60–80 cm of line and anchor the rod side so it stays taut: around your little finger with the drag holding it, rod in a holder, or in a knot-assist tool. Constant tension on the braid is the single most important factor — slack means loose wraps, and loose wraps slip.
2. Lay the leader across it at right angles, with 30–40 cm of tag to work with. You wrap the leader around the braid, not the other way around.
3. Make the first wrap. Take the leader over the top of the PE and back under, so it crosses itself on the near side. Pull it snug.
4. Alternate. Take the leader over from the other direction and back under. Each wrap crosses the top and returns on the opposite side to the last, stacked tightly, walking down the line toward the reel, flat and even with no gaps.
5. Count to 20. Most Japanese anglers teach 16–24 alternating wraps; around 20 suits casting PE in the #1.5 to #3 range. Finer main line and heavier leader want a few more, heavy on heavy a few fewer.
6. Lock with a half hitch. Pinch the wraps between thumb and index finger, take the PE tag end and hitch it around both the leader and the main line, hard against the last wrap. Pull firmly, then add two or three more hitches, alternating direction so they lie flat.
7. Set it. Grip the leader in one hand and the main line in the other and pull hard and steadily. You will feel the wraps cinch down and bite — on fluoro they often go slightly milky where they grip. If anything slides, cut it off and start again.
8. Trim and burn the leader. Cut the end of the leader 1–2 mm from the last hitch. If you like, touch a lighter to it so it melts into a small mushroom head, keeping the flame well away from the PE, which melts instantly.
9. Finish the PE tag. Continue hitching around the main line only, alternating direction, for six to ten more hitches. Finish with a two- or three-turn whipping (a Rizzuto finish) and pull tight.
10. Trim close with your PE scissors and run the join through your fingers. It should feel like a slim, hard, tapered sleeve with nothing sticking out to catch a guide.

Tying the Knot in Less Than 60 Seconds: Tension, Wraps and Locking

Knots take practice. Once your hands learn the rhythm the FG takes a couple of minutes, and experienced hands tie it in under a minute on a rocking boat. Three habits separate one that fails at the ramp from one that lands a metre-plus kingfish.

• Tension before technique. Every slipped FG we have seen came from slack line during the wraps. If you cannot hold tension by hand, use a tool — that is what knot-assist devices and bobbin winders exist for.
• Alternate, do not spiral. Wraps that all go the same way form a spiral that unwinds under load. The over-and-back pattern creates the interlocking grip.
• Hitches are the lock, not decoration. The wraps grip; the hitches stop them backing off. A minimum of three over both lines, then a proper finish on the tag.

Most shore casters run one to two rod lengths of leader, so the join sits on the spool at rest — which is why a slim connection that reels through the guides quietly matters. If you throw heavy stickbaits off the stones with a long JDM rod like the one in our Yamaga Blanks Blue Sniper review, that clean pass through the tip is the difference between a full-distance cast and a wind knot.

ISO Fishing Knots: Joining Main Line to Leader for Float Fishing

ISO fishing — the Japanese rock-shore float fishing style now well established on Australia's east and south coasts for luderick, drummer and bream — asks something different from a leader connection. You are usually joining a specialised nylon or semi-floating ISO main line to a fine fluorocarbon leader, often 2–4 metres long, with the float running on the main line above the join. The leader is light (#1 to #3 is typical) and the connection has to pass the float stopper and the rod tip cleanly on every drift.

Because the two lines are close in diameter, you do not need a friction join. Japanese ISO anglers use several accepted knots and there is no single "correct" one — what matters is that it is small, seats evenly and holds in fine diameters. The most widely taught option is the double uni knot, known in Japan as the densha-musubi or "train knot". The triple surgeon's is a quick alternative when your hands are cold, and if you fish PE main line for ISO, a slim FG brings you straight back to the method above.

How to Tie the Train Knot for ISO Leaders

1. Overlap the lines. Lay 20–25 cm of main line and leader side by side, pointing in opposite directions.
2. First uni. Take the leader tag, form a loop back over both lines, and pass it through the loop and around both lines four to five times. Moisten and snug the coil down gently — not fully tight yet.
3. Second uni. Repeat with the main-line tag around the leader: loop, four to five turns, moisten, snug.
4. Bring them together. Pull main line and leader in opposite directions so the two coils slide together and lock face to face. Pull steadily until both are hard and stop moving.
5. Trim both tags close. A compact pair such as the YAIBA-X Scissors YSC-1 is ideal for light leaders on the rocks.

On very fine leaders (#1 to #1.5) some add a sixth turn each side; on thicker fluoro four is plenty. Keep the two halves symmetrical — an uneven pair pulls to one side and weakens.

Choosing ISO Leader

A purpose-built ISO leader is worth the money. The Sanyo Japan Applaud ISO Leader Line is made for exactly this job — a high specific gravity of 1.81 so it sinks and settles quickly at the target depth, a wear-resistant finish for fishing around rock and weed, and a formulation designed for knot strength in fine diameters, in sizes #0.8 to #6. For a softer, supple fluoro that seats beautifully, the Seaguar Grandmax FX (#1 to #7) is a long-time favourite with luderick and bream specialists. Our fluorocarbon leader comparison goes deeper on the differences between brands.

A safety note for anyone rigging on the stones: in New South Wales, lifejackets are compulsory for rock fishing in declared local government areas. Rig up on dry ground before stepping onto the wet platform, and read our guide on how to read the water and set your ISO float first.

Knot Tools for Inshore Fishing, Boat and Rock Work

You can master the FG knot with nothing but your hands, and it is worth learning that way. But three tools remove the two biggest variables — tension and consistency — and earn their place on an inshore boat, in the dark, or with cold, wet fingers.

Knot-assist tools. A device such as the Daiichiseiko Knot Assist 2.0 clamps the PE under constant tension and holds it in front of you, so both hands are free for the wraps — the same result every time. It is a popular item that sells through quickly, so check the product page for current availability.

Bobbin winders. The PR knot is the FG's heavier-duty cousin and the fastest way to tie a heavy PE-to-leader connection — you load the tag onto a weighted bobbin and spin it around the leader, laying down dozens of perfectly tensioned turns in seconds. The Shimano PR Bobbin Winder Heavy Type is built for PE #1.5 to #8, covering heavy shore casting through to offshore jigging leaders where hand-wrapping thick fluoro becomes hard work.

PE scissors. Cheap scissors crush PE fibres instead of slicing them, leaving a frayed tag that unravels or snags. Proper PE scissors have hardened, finely serrated blades — the Shimano Supa PE Scissor above is fluorine-treated stainless steel that resists rust, works with gloves on and is bright yellow so you can find it on deck at night. Browse the full range of knot tools and cutters, scissors and knives to build your kit.

Testing Your Knots and the Failures to Watch For

Never fish a connection you have not tested — tying knots and testing their strength go together. Wrap the leader around your hand, hold the main line firmly, and pull with steady, serious force, more than a fish will apply. A good FG will not move at all. Cast it a few times and look at it: if the leader tag has crept out or the hitches have loosened, retie.

• Leader slides out of the wraps. Insufficient tension during wrapping, or too few wraps for the line combination. Retie with the PE anchored properly and add three or four wraps.
• Breaks at the hitches. The tag was yanked on a single hitch and cut into itself, or the hitches went on over slack. Snug each one firmly, alternate direction.
• PE parts just above the join. Heat damage from burning the leader, or a nick from blunt scissors.
• Clicks through the guides and the cast falls short. Too bulky — a long leader tag, a blob of melted leader, or messy hitches. A neat FG is barely thicker than the leader itself.
• Train knot pulls apart on a fine ISO leader. Uneven turn counts, or not moistening before cinching so the fluoro burns itself. Wet the turns and pull slowly.

Retie after any serious fish, after any contact with rock, and at the start of every session. It takes two minutes; losing the fish of the year takes a lot longer to get over.

FAQ: FG Knot and ISO Leader Knots

How many wraps should an FG knot have?

Around 20 alternating wraps is the standard most people teach, with 16 to 24 covering almost every braid-to-leader combination. Use a few more with very fine main line or very heavy leader, and a few fewer when both lines are heavy. Consistent tension matters more than the exact number.

Is the FG knot stronger than a uni-to-uni for braid to leader?

For PE to a heavier fluorocarbon or monofilament leader, yes. The FG is a friction join that grips the leader along its length and typically holds close to the main line's full rated strength while staying slim enough to pass through the guides. The uni-to-uni is a good choice when the two lines are similar in diameter, such as nylon ISO main line to a fine leader.

Do I need to burn the leader tag on an FG knot?

No. Melting the tag into a small mushroom head is optional and mainly stops it catching on the guides. If you do it, trim the tag to a millimetre or two first and keep the flame well away from the PE, which melts and weakens instantly on contact with heat.

What knot do ISO fishers use to join main line to leader?

Several are accepted. The train knot (a uni-to-uni) is the most widely taught for nylon ISO main line to fine leader, with the triple surgeon's as a quick alternative. Those running PE main line for ISO generally use an FG instead.

Why does my FG knot keep slipping?

Slipping almost always means the PE was not under enough tension while you made the wraps, so they never bit into the leader. Anchor the line firmly (or use a knot-assist tool), keep the wraps alternating and tight, lock with at least three hitches over both lines, and set the join with a hard, steady pull before trimming.

Tie It Once, Tie It Right

The FG and the train knot cover almost every JDM shore, boat and ISO situation you will meet in Australia, from trout streams to saltwater rock platforms. Learn them at the kitchen table with cheap line until your hands know the rhythm, invest in decent PE scissors and a knot tool if you fish from a boat or in low light, and test every connection before it goes in the water. Bookmark this page for the knots and tips, then stock up on genuine Japanese PE, leader and knot tools with Australian warranty from Proshop TST — and spend your time fishing rather than retying.