[QUOTE=Uncle Barry;295544]Good morning Warmfish.
If this is correct ?
"Several times I broke off just below the knot, with the loop still intact."

Then there is not a problem with the knots, there is a problem with your leader material, the Fluoc.

A two turn surgeons.
Myself, I would never even dream of a two turn knot with FC, I always use a four turn.

Two turn is ok in monofilament leaders, but not FC.
Because FC will not compress, rather it will cut its self off !


I would agree with the FC problem...while I have never had problems with loop to loop I rarely use them but if I do a bimini and a adjustable loop knot do the trick...I have had similar problem with the FC breaking mid tippet and after 3 permit losses in a row still am baffled but I took pictures as my leader kinds melted away...try new brand of FC IMHO and good luck