For all you dry fly purists, the time has come to fulfill your tying
destiny. This week we begin tying dry flies. In fact, we’ll tie a lot
of dry flies over the next few weeks, but first we need to look at what
it takes to make a dry fly float.
Some dry flies float because they are created from
materials that float. CDC is a feather from the preen gland area of a
duck that has natural floatation qualities. It floats by trapping air
bubbles in the tiny fibers that extend from the tiny shafts of each
feather fiber. If you put something on the CDC that mats down the little
fibers, it won’t capture air bubbles and it will sink.
Originally published c. July 23, 2008 on Fly Anglers Online by Al Campbell.