Snoryder,
Assuming you mean your tippet snapped at the loop:
From my experience, many loop knots do not retain a high % of strength. Using 10 or 12 lb. Maxima, my failure point will usually be the loop attached the looped fly line. My perfection loops, figure eight loops and double surgeon loops will break at the fly line befoe my tippet to fly knot breaks.
There are at least couple of ways to go:
1. Makes loops in leader material using a bimini twist or a spider hitch. Beau on this board finds non-slip loops to be very high in breaking strength so you might try that knot.
2. Use a heavier butt section, as Sinktip suggests. However, I recommend connecting tippet to butt section with a double uni-knot [Duncan loop] which is well suited to connecting lines of different diameter. My choice for butt section is 20 or 25 lb.
An unconventional solution is to intentionally use weaker tippet to fly knots so breaks always occur there, but this seems counterproductive.
Assuming your fly line loop broke:
Make a new loop and secure it with two five-turn nail knots using 12-15 lb Max, or whip the loop with tying thread and bobbin or the hand held method Dana recently posted.
I put small loops in the ends of all my sink tips. When they wear, put in another.
