ZIPPER LIFE 101
What's the first indication your zipper needs replacing? When the zipper opens while you zip it. Some say, "just replace the slide." Replacing the slide alone is a temporary fix, and eventually, the same issue will happen. The same can be said when installing a new zipper and using the original slide because it is brand specific. In most cases, the slide will not work correctly with the zipper.
It is cost-effective to replace the zipper complete with a new slide. The zipper is one item, that if done right, is not noticeable when replaced. The average person will not be able to tell where the bag was open for the repair. When replacing a zipper, the size, color of the tape/teeth, and the material (metal or nylon) are matched to the original.
What is the best way to lubricate a zipper? Gently rub candle wax on both sides of the zipper. Then open and close the zipper a few times to spread the wax. The zipper should open and close easier.
Don't overstuff your bag. It causes undue stress on the zipper and may lead you to zip one of your items in the zipper.