I thought he addressed both the starting ends and what to do if you
didn't want it to separate all the way..

There is only one starting end and one finishing end. The problem is not
that the slider is going off the end of the zipper. It is the starting end that
has the broken pieces. Either the zipper can't start in the closing operation,
or if it is already closed, the starting end can open without the slide passing
over it. Since the zipper can only mesh the teeth in the closing direction,
it becomes inoperable and the zipper cannot be opened. Both cases are
bad news.



FWIW, If the bottom end of a zipper fails, and I don't want the slide
to go all the way down and come off, I put a safety pin across just
before the end.

That works for the 'bottom' or closed end. It doesn't help the starting end.
YKK is supposed to be one of the best zipper companies for marine applications,
yet they produce these junky products that will not hold up in that kind of
environment.
To make things worse, they make the zippers unrepairable, incurring the expenses
I previously mentioned. About a year ago, they came out with a UV resistant
zipper,
which was too late to be used on my cover. I have not idea if this 'upgrade'
really solves the
basic problem, and I'm not sure YKK will do anything to make this right.

Sherwin D.

grandma Rosalie