I am looking for a knot to tie it for the day, while on the water. I
normally do not carry acetone, etc when fishing.
Bill

Quick field repair of a cut fly line:

Take about a foot of tippet, 2X or 3X will do.

Make an overhand knot in the middle.

Put about an inch and a half of the broken end of the fly line into the
overhand knot and pull it as tight as you can.

Then grasp the tippet tag ends in one hand, the fly line in the other,
and yank hard. This will strip the fly line coating off the core.

Repeat for the other broken end.

Tie a double surgenon's knot joining the two core ends together. Snug
the knot up to the ends of the coating so as as to reduce as much as
possible, the distance between the ends of the coating.

If you have any knot glue with you like Loon Knot Sense, coat the
double surgeon's knot and the rest of the exposed core to seal it and
to smooth it out.

When you get home, whip finish it to smooth it down and eliminate
hinging.

Peter