I must not have drained my cottage pipes too well, because three of them
burst. Two are rigid copper and easily accessable, but one is flexible
copper where there is only 16" between the ground and the floor joists. I
am not looking forward to it.

I have never worked on flexible copper before, but am not at all confident
that it is still round. Will I have any problem sweating fitting on the it?
Any great advice on this?

Is there anyway to mend the break? It is in a place where a leak will not
do any damage, so I don't need 100% certainty; I can alway just cut out the
mend if it doesn't work. I have fiberglass and epoxy; is that worth a try?
Fiberglass won't be fun in that little space, but will be better than trying
to replace the damaged section. Any other ideas?

thanks

I did everything the same as years before, except that after I drained, I
closed the valves; figuring I could save myself a trip into the crawl space
in Spring. I can't imagine where the water came from, but it did. Live and
learn.