Demonick's Kayak Fishing Pages: Do-It-Yourself Halibut Harpoon

Home           Last updated Tuesday, 2012-02-07
The well prepared halibut angler never leaves home without a harpoon, shotgun, or pistol. Since firearms are particularly problematic on a kayak, here I describe a DIY halibut harpoon.

Overview of complete finished harpoon

Closeup of tip shaft and cable

Close up of tip

It will take just a few minutes to collect the parts at Home Depot and 30 minutes at home in assembly. Parts will build 2 harpoons. You could find the tube and rod cheaper. Stainless would be best, copper would work well.

These are the dimensions I used:

Smash the first 1-1/2" of the tube in vise, then pound flat. Grind the tip into an arrowhead. Grinding may heat up the aluminum enough to weld the tip together. Sharpen with a hand file. If using a copper tip, you might want to solder the seam in the point. Also, to harden copper heat to glowing then allow to cool slowly in air. This is the opposite of iron-based metals.

Drill a hole 2-1/2" from tip. You want it balanced so adjust the hole position accordingly. Note the the hole is drilled parallel to the plane of the arrow tip. This holds the flat of the tip against the fish. Cut tip off at 4-1/2" and clean up the cut.

Cut the wood handle at 22". Drill a 5/16" hole 3" deep in cut end of wood handle. Repeatedly drop the wood handle on hard floor and the rod will drive itself into the hole.

Loop wire rope through tip and crimp. Crimp other end in another loop. The photos show an error which you should correct. Make the loop through the tip long enough so the ferrule is BEHIND the tip. You want the ferrule to follow the tip through the wound channel, and not be forced through the wound channel beside the tip.

Finished. Remember the tip is loose on the shaft and will fall off easily. A small zip-tie or rubberband can be used to keep the tip on the shaft. A line should be clipped to the end loop at all times so if the tip falls off it is not lost.

A harpoon is used to tire a halibut in order that it can be dispatched more easily from the precarious perch of a kayak. A float of some sort, generally a crab float or larger, is attached by a line to the cable on the shaft of the harpoon. The halibut is brought up headfirst to the side of the kayak. Be careful to keep the head under water. Harpoon the fish through the belly. It is their softest spot, yet strong enough not to tear. The harpoon must completely pierce the fish so the tip will be free to rotate and lie flat along the fish. The halibut will likely make a run when you harpoon it, but it will be dragging your float(s). Follow it and when it is exhausted, bonk it hard and repeatedly, or use a knife to pierce the brain.