CDC Split Wing Dun

[scotfly]

This is a Marc Petitjean style dun. Simply alter the colours to suit.
You can tie the tails in ?outrigger? style or as a bunch.
I have used micro foam to split the wing, but anything will do really. Floss, yarn, etc.

Instructions assume right handed tyers

HOOK ? TMC 103 BL # 17
THREAD ? UTC70 Brown Olive
TAIL ? Coq De Leon (Pardo Claro)
BODY ? SLF MC8 (BWO) or any fine dubbing you prefer
WING DIVIDER ? Hareline Dubbin Inc Micro Thin Foam, Olive
WING ? 4 CDC Feathers

STEP 1

Attach the thread and wrap to the point shown.





STEP 2


Tie in the foam wing divider.





STEP 3


Prepare the wings by first taking two CDC feathers and matching them up by their tips as shown.




Then take another two CDC feathers and do the same. Then take the two pairs of CDC and match them by their tips back to back as shown.





STEP 4

Tie them in on top of the shank as shown. If you tie them in with a couple of loose turns
of thread you can adjust them for length by pulling the butts.





STEP 5

Trim the butts and overwrap with tight turns of thread to secure the wings.
Then lift the wings up and take a few wraps in front to hold the wings in the upright position. I prefer
to leave mine slightly advanced





STEP 6

Pull the foam between the wings dividing equally, then tie down behind the wing.






STEP 7

Wind the thread to the tail and dub on a small pinch of dubbing to form the outrigger tails.



STEP 8

Tie in the tail fibres. I like to tie two in on each side.



STEP 9

Apply some more dubbing to the thread and wrap to form the body.
Take the dubbed thread tight up to the base of the wings then use the same dubbing to form the head.




STEP 10

Whipfinish and varnish for the completed fly.







Outrigger and normal tail side by side.

[scotfly]

This little fella accounted for 5 Browns today and 1 Grayling.  The other 2 Browns and 3 Grayling fell to a CDC & Elk.

[scotfly]

Yes, they also, depending on the angle of the split, determine how the fly sits on the water.

[haresear]

Just a general observation. If you cock the tails upward slightly, that helps any fly land and sit true.

Alex

[Wildfisher]

Just a general observation. If you cock the tails upward slightly, that helps any fly land and sit true.

are you sure Alex? I cock up most of my flies and they generally land upside down 

[haresear]

I cock up most of my flies and they generally land upside down

:lol: :lol: :lol:

You must show me how to tie USD flies

Alex

[scotfly]

Just a general observation. If you cock the tails upward slightly, that helps any fly land and sit true.

Alex

I don't know anything about aerodynamics or physics Alex, so I'm not doubting your statement. However  :shock: I cannot find any reference in my books to back it up, only references I can find  relate to stability on the water.
However again  :shock: :shock: I can find reference to "cocking" the tails on USD flies, so maybe Freds onto something.  :lol:

[haresear]

I can find reference to "cocking" the tails on USD flies

Exactly, Scotfly. The point of the cocked upward tails is to work in concert with the wings to flip the hook over so that it lands upside down. The aerodynamics are pretty obvious really.

So it stands to reason that upward pointing tails on a conventional (hook point sub surface) pattern can only assist in ensuring that the fly lands bottom first.

I'm sure that the split wing CDC would do this anyway and perhaps I should not have posted what was really a general observation on this particular thread, so sorry for hijacking your thread (worst thing that can happen to a flydresser .)

Alex

[scotfly]

I'm sure that the split wing CDC would do this anyway and perhaps I should not have posted what was really a general observation on this particular thread, so sorry for hijacking your thread (worst thing that can happen to a flydresser .)

Alex

No need to apologise you are right to add your observations, I welcome and thank you for your them.

[scotfly]

Just a general observation. If you cock the tails upward slightly, that helps any fly land and sit true.

Alex

I don't know anything about aerodynamics or physics Alex, so I'm not doubting your statement. However  :shock: I cannot find any reference in my books to back it up, only references I can find  relate to stability on the water.
However again  :shock: :shock: I can find reference to "cocking" the tails on USD flies, so maybe Freds onto something.  :lol:

OMG I'm fallible  :shock: Just finished reading (again) What The Trout Said (about the design of trout flies and other mysteries) ; Datus Proper and after saying I could find no reference to cocking the tails I came across this on page 250 .... " But the tail will markedly affect the way the fly lands and floats. Some fly-tyers like to tip the tail down, hoping that it will elevate the hook off the water. This might work if the fly could be placed on the water by hand, carefully, in exactly the desired position. In fishing, however, the down-tipped tail turns the fly over on its back. You don't want this, clearly, if the fly has wings in the normal position. For winged flies, rock the tail slightly upwards and divide it. This makes the fly much more likely to cock"
I bow to your knowledge haresear  :cheers;