Originally Posted by MoscaPescador
You are correct. That nail knot will not hold up. You can use a braided loop made of 50 pound braided monofilament.
I would skip the loop. Create a three foot butt section of 30 to 40 pound monofilament. On the end of that, you should have a loop made from a Bimini Twist. Connect that butt section to the fly line using an Albright Knot. From there, you can make speedy loop to loop connections to your class tippet.
How about the other end of the fly line ? How do I connecting it to the backing?