Whip finishes "the old way"
When you want to whip finish the head of a fly, try the old way - double over a piece of 4x tippet mat'l, place it on the head of the fly, make 10 wraps of thread over the head/tippet, place the thread through the open "loop" of tippet, then pull through using the tag ends of the tippet. Trim the pulled-through thread.
After putting on head cement, you will be surprised at the durability of the fly!
Haven't used a whip finisher in years! This beats virtually all of 'em for speed and resulting durability.