Arbor Knot — Spooling Line to a Reel
April 26, 2026
What Is the Arbor Knot?
The arbor knot is the simple knot that attaches new fishing line to your reel spool. It’s the first knot most anglers tie when spooling new line — and it’s the most overlooked. Tied correctly, it locks the line to the spool so that even if you somehow run all your line off the reel, the line doesn’t pull free.
How to Tie an Arbor Knot
- Pass the line around the spool arbor (the metal core of the spool). Bring the tag end back so it lies parallel to the standing line.
- Tie an overhand knot in the tag end around the standing line. Don’t tighten yet.
- Tie a second overhand knot in the tag end (a “stopper knot”) about 1/4 inch below the first.
- Wet both knots.
- Pull the standing line — the first overhand slides down to the spool and tightens. The stopper knot prevents the first knot from slipping back through itself.
- Trim the tag flush with the stopper knot.
The line is now firmly attached to the spool. You can begin spooling.
Important Setup Tips
Use tape on slick spools. If you’re spooling braid (which is slippery) onto a smooth aluminum or plastic spool, the line can slip even with a good arbor knot. Wrap a strip of electrical tape around the spool first, or apply a strip of mono backing over the arbor knot before spooling braid.
Wet the knot before spooling. Pulling line under tension while spooling generates heat — a dry knot can fail.
Fill the spool to the right level. Spinning reels: fill to within 1/8 inch of the spool lip. Baitcasters: fill to within 1/8 inch of the lip. Fly reels: fill until the line comes off the reel without rubbing the cage. Underfilling causes casting distance loss; overfilling causes tangles.
When to Skip It (Use Backing Instead)
If your main line won’t fill the spool, add backing first. Common scenarios:
- Fly reel: 30+ yards of 20 lb braided backing under the fly line
- Baitcaster with short fluoro spool: 30 lb mono backing first, then connect to fluoro with a uni-to-uni
- Lake Michigan downriggers/trolling reels: 100+ yards of backing under main line
For these, tie the arbor knot to the backing, then connect the backing to the main line with a double uni or albright.
Indiana Applications
- Every reel you own — every spool of line attaches with an arbor knot
- Spring reel maintenance — most Indiana anglers respool one or two reels each spring
- Line replacement after a snag — when you have to retire damaged line and respool
The Bottom Line
The arbor knot is one knot every fishing angler should learn. It’s not glamorous, it’s not heroic, but tied wrong it can cost you a fish on the day you hook the biggest one of your life and run out of line. Take the extra 30 seconds to tie it right.
Frequently Asked Questions
Why does my line slip on the spool when I spool a reel?
Three causes: not enough wraps in the arbor knot (use seven), no tape on the spool to give the knot something to grip (especially needed for braid on slick spools), or the knot didn't seat tightly. Wet the knot and pull it down hard before spooling.
Do I need to put backing on a reel?
It depends on the reel and line. Spinning reels: usually no — just fill the spool with your main line. Baitcasters: sometimes — if your main line is short of filling the spool, add 30 lb mono backing first. Fly reels: yes — backing fills the arbor and helps line lay correctly. Conventional reels for trolling: yes, often.
Is the arbor knot strong enough?
It doesn't need to be strong — the arbor knot's only job is to keep line attached to the spool when the spool empties. As long as it doesn't slip, strength is irrelevant. A simple double overhand or improved clinch works fine; the arbor knot's specific design is just optimized for this single use case.