There are few things more annoying than a broken zipper on an item of clothing or piece of equipment. Sure, a broken zipper on clothing can be replaced by a functioning zipper, but the process is laborious for those with the sewing skills to do it, and expensive for those without those skills, assuming that a replacement zipper of the correct dimensions can be found. Usually in this disposable culture, the item would simply be junked....well here is a last chance option that may be worth trying. I have tried it myself, and have had some success with it. Try it....there's nothing to lose, and everything to gain.