First time I've had this happen.
I tried attaching 20 dacron to a new Rio Grand 6wt floating line this weekend. Used the same old knot I usually do for backing (similar to a nail knot, forget the name). It cut the line, and stripped it off the core when tightened. Tried several times, with same result. Even tried a nail knot, with same result. Have NEVER had this happen with my usual lines (444 floaters, 444 sinkers, 444SL).
Anyone else experience this?
What's the knot to use with this line? I assume it's getting cut because it has a non-compressible core and the coating is soft(?).

Many Thanks,
Troy