Fly Tying Group: At the Vise
Underwire Support
Russ Forney

(Originally Published on the Hatches Magazine website)

Sorry Victoria, the secret is out: underwire support is the key to a flattering figure. Strategically placed and properly fashioned, short segments of wire are an excellent foundation for the broad, flattened abdomen characteristic of large nymphs. The shapely bulk of underbody wire makes an attractive chassis for subsurface flies, providing just the right visual cues to tempt feisty trout.

As with the allusion to a shapely figure, achieving the proper shape for a fly begins with a well-proportioned underbody. From the very first thread wraps until the final knot is tightened, shaping the fly is a continuous process. Fly bodies are progressively contoured during the tying process: tapering the cut ends of hair wings, smoothing the transition between wings and tail, and building a solid base to give structure to the finished product. The same holds true when counter-spinning tying thread to flatten wraps underlying a slender abdomen, avoiding excess bulk on a minuscule Tricorythodes or late-season olive pattern. The tier’s task is to blend each thread wrap and material into a body trout find irresistible.

Wire is an excellent material for adding heft to a fly. Some recipes involve spiraling wire around the hook shank, often under the thorax or midsection of a pattern. An alternate approach, mounting strips of wire laterally along the sides of the shank, not only adds weight to the hook, but is also the underpinnings of a broad, tapered abdomen. With a solid wire foundation in place, other materials used in the pattern can also be incorporated into the underbody design. The end result is a firm base that supports and defines abdomen; a key element when imitating the robust, laterally-flattened body of stonefly nymphs.

Underbody shape is infinitely adaptable to complement specific hook sizes and fly proportions. Whether you want to enhance curves or build a flat abdomen, underbody construction greatly influences a fly’s final appearance. Every material in the recipe is used to augment body shape and structure.

The accompanying tying sequence features a stonefly nymph built on a wire-weighted frame. A short segment of wire mounted along each side of the hook shank makes a stout platform for the large fly. The nymph’s undercarriage is further accentuated with waxed dental tape, an inexpensive material tailor-made for shaping large flies. Dental tape is pliable and adheres loosely to itself, greatly aiding placement and repositioning. Tape wraps can be lightly flattened with a pair of flat-nosed, non-serrated pliers and the finished underbody is easily colored with permanent markers. Silk or rayon floss also makes an excellent underbody covering and colors can be selected to enhance contrast when visible through gaps in the segmented abdomen or when viewed through an overbody of clear monofilament or microtubing.

Wiring the underbody is not limited to lateral placement, an additional piece of wire lashed to the top of the hook shank increases the thickness of the abdomen as well as further weighting the pattern. Lifelike symmetry is achieved by tapering the ends of the wire toward the tail of the fly. Whether mounted along the sides of the hook or tied to the top, flattening the ends of the wire segments before mounting them to the shank gives a realistic taper to the overall body shape. Lead-free wire is soft and malleable, readily molded and crimped with tying pliers. The flattened ends are easy to anchor to the hook with tying thread and a thin coat of clear nail polish over the thread-wrapped bundle makes a bulletproof substructure; sturdy construction is important for weighted patterns destined for the rocky bottom of a fast flowing stream.

The featured pattern is finished with solid black plastic microtubing mounted along the top of the hook shank, top-mounting the material complements the thickened appearance of the abdomen and firmly anchors the plastic tubing. Many variations in color, texture, and materials are possible for finishing the stonefly abdomen and tiers can refine the pattern to meet their needs.

A short piece of wire added along the top of a curved hook also helps define the underbody shape of scud patterns. The extra weight drops the fly deeper into the water column and a slight thickening along the back of the fly accentuates the humpback appearance characteristic of drifting scud. Flattening both ends of the wire results in a double taper for the underbody and provides a stable platform for finishing the fly. Recipes for weighted scud patterns abound, the most recent example to cross my tying desk was Gary LaFontaine’s Rollover Scud, recreated in Al & Gretchen Beatty’s book LaFontaine’s Legacy. If you fish weedy spring creeks, lightly weighted scuds are an excellent investment for an evening at the tying bench.

The defining visual elements of a fly pattern are not limited to the outside appearance, successful imitation begins with a firm foundation and a well-shaped underbody. The right blend of materials and techniques makes an alluring package for hungry fish. If you want to enhance the look of your patterns, underwire support adds a seductive shape that trout cannot resist.

Recipe for a weighted stonefly nymph:
Hook: Curved nymph hook, sizes 2-12
Thread: Danville 3/0 nylon monocord, black
Weight: Lead-free wire mounted parallel to the hook shank, wire size to match hook
Underbody: Dental tape wrapped over the wire bundle, colored with a black marker
Tail, legs, and antennae: Goose biots, black
Abdomen: Black plastic microtubing or ribbing material
Thorax: Course black dubbing
Wing case: Segments cut from a black turkey tail feather, top-coated with clear nail polish

1. Wrap a thread base and add 2 goose biots to form the tails, a small thread bump at the end of the shank splits the biots nicely. Flatten the end of a piece of wire and mount it securely to the far side of the hook shank; the wire extends from near the biot tails to a position 1-2 eye-lengths behind the hook eye.

2. You can now add a piece of wire to the near side of the hook. Tying pliers are used to flatten the end of the wire prior to mounting.

3. Once both pieces of wire are securely mounted, wrap the underbody with tying thread to form a cocoon around the wire. You can use your thumbnail to position the wire bundle evenly along each side of the shank. When you are satisfied with the positioning, add a drop of nail polish to hold the thread-wrapped bundle in place.

4. Tie a length of black plastic microtubing along the top of the underbody, followed by 8-10 inches of waxed dental tape.

5. Wrap the dental tape forward to form an underbody that tapers at the tail, use multiple layers of tape to add bulk to the abdomen. Waxed dental tape is pliable and adheres lightly to itself, it is an easy material to work with and can be repositioning to achieve the desired shape.

6. Once you have wrapped the underbody, anchor the dental tape and trim off the excess. Tying pliers can be used to crimp and press the dental tape wraps to refine the underbody shape. The underbody is then colored with a black permanent marker.

7. You can now wrap the plastic microtubing forward in touching turns to the midpoint of the body. Notice how the underbody defined the outward appearance of the abdomen and helped create realistic symmetry and shape.

8. Add a pair of biot legs and cover with several wraps of course dubbing; mount a wing case over the dubbing to make the first of three segments for the thorax. The wing case is cut from a black turkey tail feather previously coated with clear nail polish.

9. Add a second segment to the thorax with biot legs and a final segment without legs; taper the final segment toward the hook eye to finish the thorax. Add two more black biots for antennae, build a thread head, and finish with several whip knots. Notice how the hook eye is used to splay the antennae from the head, this extends the biots from the hook and keeps the eye accessible.

10. This silhouette shows how the tubing and dental tape added bulk along the top of the abdomen, complimenting the shape and structure of the nymph. Trout pay attention when this beauty dances along the streambed.

Recipe for a weighted scud:
Hook: Heavy wire curved hook, sizes 10-18
Thread: Danville 6/0 waxed nylon
Underbody: Double tapered lead-free wire, bundled with tying thread
Tail: Wood duck fibers
Body: Sow-Scud dubbing (rear) and Ice Dubbing (behind the hook eye)
Rib: Copper wire
Back: 1/8 inch wide strip of plastic cut from a sandwich bag

1. A short segment of lead-free wire, flattened at both ends, forms the underbody on this weighted scud pattern. Mounted along the top of the hook shank the added bulk of the wire enhances the humpback appearance of the fly.

2. The finished pattern is a sure bet on weedy spring creeks. A couple of wraps of Ice Dub behind the hook eye are brushed back over the body.