Tying the Strong Arm Merkin

Tying the Strong Arm Merkin
Dave Skok photo

Hook: #2 Mustad Signature Series S71

Thread: Cascade 210 denier – cream – (or Danville Flat-Waxed Nylon)

Weight: standard Wapsi lead dumbbell eyes, x-small, mounted opposite the hook point-side of the shank. Paint the eyes and thread with nail polish that corresponds to the intended crab color.

Claw/Arm: Large (4mm) Cascade Ultra Chenille, white, knotted, trimmed, burned to crab claw shape, with one tip longer than the other. Mark with permanent markers and allow to dry. As shown: neon orange, golden olive, and brown Sharpie pens.

Dubbing/Underbody: Scrap sparkle yarn mixed 1:1 with white rabbit fur, dubbed loosely and combed/brushed rearward. Make sure to clear any excess dubbing that might obscure the claw.

Collar: Whiting Hen Saddle feather, white/cream, wrapped and then trimmed on the bottom (trim dumbbell side).

Carapace: Sparkle Yarn, tied in figure-eight style, 2 bunches at a time, trimmed to curved and tapered shape – white and cream shown.

Legs: 3 Silicone legs, knotted between yarn bunches - clear with orange tip and olive with black flake shown.

Glues: Thin cyanoacrylate (super glue); thin acrylic resin.



1. Put a #2 S71 hook in the vise and lay a multi-layer base of 210 denier thread near the hook eye and back some. The thicker thread base helps keep the eyes from spinning around the shank, as well as lifting the weight away from the shank for better keeling.


2. Firmly attach the lead eyes with figure-eight and parachute wraps with a dose of thin super glue along the way. Th eyes should be placed on the top side of the hook (away from the bend), about 1 to ½ eye-length back from hook eye. Tie off. I paint the lead eyes with an appropriate color nail polish and let them spin on a drying wheel. Painting is optional, but it looks nice. Please use adequate ventilation should you choose to paint the eyes.


3. Make a single-turn Surgeon's Knot with a loop of Large (4mm) Cascade Ultra Chenille. Pull the loop tight with the tips of stout scissors. Cut the loop on an angle to make two tips of unequal length. The longer (top) claw tip should be about 1/3” to 1/2” long. Leave an inch of material to form the arm.


4. Burn claw tips to shape with a lighter or candle flame and let cool. Mark claw and arm with permanent markers and let dry.


5. Firmly tie in the pre-knotted and pre-colored arm/claw assembly so that the longer claw tip faces down. (And, therefore up, when later inverted.)


6. Inject acrylic resin in between the two strands of chenille and around the tie-in point.


7. Hold to shape, angling slightly down towards the hook bend, and cure in place. Do not be random or sloppy about the angle and straightness of the claw as it has great impact on how the fly swims and sinks.


8. Inject resin in to all three corner areas of claw.


9. Hold claw open to “V” shape (about 60 degrees) and cure in place.


10. Make numerous wraps of thread back over the glued portion of arm and then back to tie-in point.


11. Loosely dub yarn/rabbit mixture on to the thread and wrap the dubbing around the tie-in point, and back on to the arm, and then back up the shank to just past the hook point. Quite a bit of loose dubbing is required.


12. Brush back the dubbing around the glued arm. Make sure to pull out any excess dubbing that might obscure the claw.


13. Wrap back over the dubbing a few turns and tie in a Whiting Hen Saddle feather, just in front of the hook point. Wrap touching turns until you run out of feather.


14. Pull the hackle down towards the hook point while simultaneously wrapping the thread rearward, as you would for a wet fly beard. Continue back until in line with the hook point and then smooth out the remainder of the shank with numerous turns of 210 thread.


15. Return the thread to the hook point area and invert the hook. Figure-eight on a bundle of 2 pieces of sparkle yarn (white and cream, as shown), to the hook-point-side of the shank, directly next to the hackle collar. The yarn tie-in point is directly in line or just in front of hook point. It is very important that the first yarn bunch be locked to the shank in a very solid fashion. It is even more important that the yarn be attached on the hook point-side, NOT the dumbbell side.


16. Advance your thread a few turns and repeat with additional yarn bunches, leaving a little space between each application for the addition of legs. Depending on the lead eye size, it will take 4 or 4 ½ or 5 bunches of yarn to fill the shank of a #2 Mustad S71.


17. Whip finish, once complete.


18. Straighten the bunches so that each color stripe is in order.


19. Hold the far-edge yarn strands out and trim with curved scissors on a mild curve. The yarn should be shorter near the lead eyes and longer near the hackle. Stout, serrated, 5” scissors work best for this operation.


20. Repeat for close side.


21. Clear any snarls in the yarn body with a dull bodkin.


22. Comb out the yarn body with a fine-toothed comb, so everything is neat and clean.


23. Trim excess fuzz off both edges.


24. Trim off bottom of hackle (lead eye-side).


25. Take 3 silicone legs and knot them between yarn bunches, one at a time, with a simple overhand knot. The 3 legs should fit nicely in between 4 or 5 yarn bunches. Make sure the legs are coming out from within the yarn, not above or below.


26. Trim the legs to the length of the yarn carapace, or slightly longer.


27. Apply thin super glue to the head and to the exposed thread along the top of the yarn body. Allow a little glue to soak in to the yarn body and leg knots.


28. Apply thin super glue to all exposed thread on the bottom and to the clipped hackle area. Add a little extra glue to the yarn body nearest the shank.


29. Inject small amounts of thin acrylic resin in to the yarn edges, precisely where the legs come out.


30. Hold your legs exactly where you want them and set them in place with the light. It's easier to do one side at a time.

31. Catch permit.

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