I then stumbled onto Solarez Flex formula UV epoxy. Not only does it penetrate the thread bonding it together, but it also creates a strong and flexible shell around the loop. In fact it is even more flexible than most of the factory bonded loops on my fly lines. To apply, just squeeze a few drops at a time and use something like a toothpick to smooth out. Hit it with your UV torch and keep adding until you have enough. Solarez UV products are available at almost any Fly Tying suppliers.