The spool knot, better known as the arbor knot, is the simple connection that ties your fresh line to the reel’s spool (the arbor). It is the very first knot you tie when you re-spool a reel, and its only job is to grip the spool so the line does not spin freely when you set the hook or a fish takes drag.
When and why to use it
Use it every time you put fresh line on a reel. It is quick and foolproof. One important note for braid: braid is slick and can slip and spin on a bare arbor even with a good knot, so either put a few wraps of monofilament backing down first, use a piece of tape on the arbor, or a reel with a braid-ready spool, then tie the braid to that.
How it works
You pass the line around the spool, tie an overhand knot around the standing line, then tie a second overhand knot in the tag end as a stopper. When you pull the standing line, the first knot slides down and jams against the stopper knot, cinching tight against the arbor. Trim the tag and start winding.
Tip For braid, back the spool with a bit of mono first or tape the arbor, then tie the braid to it. Braid tied straight to a slick spool can slip under drag, no matter how good the knot, so give it something to grip.