Tie-fast Nail Knot Tool
How to tie the Knot Tyer Nail Knot. The Tie-Fast Knot Tyer (Buy one here) is a handy tool for tying a Nail Knot on a fly line. This knot can be used to attach backing to a fly line and a leader to a fly line. The inexpensive tool which is called a Tie-Fast Knot Tyer makes short work of tying the Nail Knot. Instructions come with the tool but in case you have lost them, here is how to tie the Nail Knot.