I am setting up a rod for shark fishing at the beach next week and trying to add about 20' of 80lb mono leader to my 30 lb. mono. I tried tying my usual double-uni knot to join fishing lines but the 80lb line didn't want to cinch down into a tight knot. When I cut the tag end off it actually unraveled. I lubed it with spit before tightening. I can try it again and maybe work the knot better but wondering if this is the right knot for joining such a heavy leader?

 

I do have 50 lb. mono leader I can use instead but was trying to tie on the heaviest I had to both endure any abrasion and also give me some heavy line to pull a shark up the beach a bit.

Mono for shark leader?

I will use steel for the actual leader to the hook. The 80lb is considered shock leader to prevent abrasion breakoffs

Blood knot

Allbright knot also works here - I also use Allbright knot to attach wire leader to finer mono.  

 

Adding a braid note - in Japan, they offer surf braids where e.g., PE#2 running line is tapered to PE#7 braid shock leader.  Then you only need a short piece of shock fluoro to wire. 

I used to make them with double barreled leader sleeves. 

The crimp kind. 

The challenge here also includes the knot going through the guides and tiptop. 

Also every shark I’ve ever caught was on mono. 

2 hours ago, MickD said:

The challenge here also includes the knot going through the guides and tiptop. 

 

Yep, I just learned this 30 minutes ago after getting a knot to snug down decently. Good knot but big and not happy with the upper rod guides. I'm going to have to shorten my leader to whatever can stick out the top guide when I cast.

60# Maxima UG copoly (.031D) to 5’ 49 strand AFW steel 175# leader with 130# Spro swivel crimped to leader.60 # pound is stronge enough to withstand shark tail abrasion and pull the fish onto the beach.

Standard Improved Clinch knot works with mono/copoly line to swivel.

Tom

could you use a palomar knot on each side of a swivel to join the two sections?

I use an Alberto for 20PE-40lb mono or 50FC and it works really well.  If youre surf fishing with bait I would suggest a barrel swivel over a connection knot.  Sometimes that bait can roll in the current and really twist the line.

Another option using hollow braid is make up a wind on top shot leader using 80 mono joining the wire leader using a swivel and crimp sleeves.

Tom