No one can argue these days that CDC is a fantastic material for dry flies, and other flies too for that matter. The Cul de Canard feathers has a natural oil floatant to it that makes them superb for floating flies. The CDC flies are situated around the preen gland of many birds and this gland is used by the birds to waterproof their feathers from oil secreted from this gland. But it is not only the oil that makes CDC feather so buoyant it is also the structure of the feathers themselves that makes it trap air bubbles, so good that the air bubbles remain trapped in the fibers of the feather even if they are submerged. This makes it also a really good material to use to mimic sparkle pupa appearance in caddis pupa flies.
This fly that I want to show here is a rather simple but dead effective loop wing caddis. It is a rather long wing with a special appearance, hence the name of the fly. Also I use a little unusual material for the abdomen, you can of course use any other that you are fond of, like nymph skin, flex skin or even just a dubbed and ribbed back body. The flat flexible jewelry “thread” that I have used here are very similar to flexy floss I think.
Fish it actively either when there is hatches of caddis fly or when they are fluttering around on the surface for egg laying.
Hook: Partridge K14ST size 10-14
Thread: UNI 8/0 olive
Abdomen: Flat flexible jewelry thread
Thorax: Dark olive dubbing
Wing: Three tan CDC feathers
Start with catching in the flex thread and tie it down while stretching it all the way the hook bend.
Dub your thread and wind it forward to create a nice caddis tapered underbody. Remember to not make it to thick since the flex thread creates quite a bulk when winded forward.
Now wind the flex thread forward without stretching it very much, as i get closer to the hook eye I usually stretch the two last segments a little harder. Tie down and leave room for the thorax and wing.
Color the abdomen with a permanent marker. These days when I tie this I color the flex thread before winding it.
Take three good sized tan CDC feathers, lay them all together with the tips in line and stroke the fibers forward. Then tie them in with just two loose wraps of thread leaving about 1 cm of the feathers pointing forward over the hook eye. Of course if you tie this one in smaller sizes you will use only two or perhaps only one CDC feather, but for sizes 12-14 I like to use three.
Now pull on the CDC fibers backward so that more fibers are trapped down leaving just the three short tips forward. Now secure this with several hard wraps of tying thread.
Now dub the thread with a small amount of dubbing and wind forward to further trap down the tips and create a small thorax area.
When folding the wings forward I like to first fold them forward to the right length and then secure the fold by the hook eye. Then I heat a dubbing needle for a few seconds and carefully put it in the loop and pull backwards slightly for 2-3 seconds. This will create a more narrow tear drop shaped wing. Don’t worry if you have fibers “loose” back from the wing, this will only enhance the fluttering look of the fly.
Now carefully cut of the three quills of the CDC feathers off but leave all the fibers sticking out over the hook eye.
Try and spread the CDC fibers evenly on each side of the hook eye and fold them backwards making sure some will also be on the top. Then tie them down perhaps a mm or so behind the hook eye to create a small head too. Here’s a top view where you can see how the fibers are now back on each side of the hook shank.
Now finish off the fly there and varnish the tie in point.