Willis Knot for Connecting Leadcore to Mono Leader
This is for connecting the leadcore both to the backing and the leader.
Make a loop in the leadcore, about 4 inches from the tag end.
Next step is to slide back the outer coating (Sheath) on the leadcore line, approximately 3 inches.
Cut the lead off, then slide the out coating (Sheath) back out until it's snug.
Ensure that the end of the monfilament you are going to insert into the dacron sheathing is cut at a slight angle or flat. You don't want it "Flattened" like when you bite it off ;} .
Insert your monofilament leader, so that it butts up with the lead inside, then work the knot down towards the tag end (Keep the monofilament butted up against the lead inside as you work the knot down).
Pull the knot tight, holding the dacron on each side of the knot, then snug it up tightly, holding the monfilament/leadcore to really cinch it down.
We have used this knot for years and never had a knot let loose.
Once you cinch the knot down, the tighter you pull, the tigher the connection/knot gets. If you want peace-of-mind, you can tie a simple overhand knot in the mono leader material before inserting it into the dacron sheathing, then tie the second overhand knot in the dacron. You can also tie a Double Willis which is two overhand loops worked down over the mono/dacron sheath.
If you really want to secure the knot, some people use a drop of superglue or elmer's glue on the knot and let it dry.
Other Leadcore Facts:
1) Leadcore most commonly comes in 18#, 27#, and 45# test, but #45 test is not heavier weight-wise than #18 test. The difference in weight sizes is the strength of the dacron sheathing por of the line and it's relative strength.
2) All three weights of Leadcore (#18, #27, and #45) have the same depth scale. ~Roughly 4'-6' per color.
3) Several manufacturers of leadcore line suggest that after 25 feet of depth, thermocline affects the sink rate (The water density increases). They suggest 3 colors is ~15' down, 5 colors ~25', 8 colors 30', and 9 colors 35'.