one thing to do is to change your thread. if you can find it use uni-big-fly-thread. here's a link: http://www.uniproducts.com/english/produits.html
if you've ever used kevlar thread you might have noticed that it does break. i've used a full spool of this and never broke the thread. on the same flies though i did break the kevlar thread. that would be my choice in thread. as far as the nail hardner go for it. i was the one that recommended it to gregorykicks and i believe fshfanatic added the brand and cutting the tip down.
no matter what all i'm gonna do is: WISH YOU THE BEST OF LUCK.
let us know how you do.