Zippers are everywhere -- on jackets, toys, clothing, shoes and many types of bags. In fact, it can be difficult to find bags designed for travel, such as backpacks, suitcases and duffel bags, that do not have zippers. These travel bags often come with several pouches or compartments with zipper closures. Because duffel bags are often thrown around, such as when they're used to carry sporting equipment, their zippers can wear and break more quickly than those of other types of bags.
Determine what part of the zipper is broken and what needs to be fixed. For example, if the zipper pull tab has broken off the slider, simply purchase another zipper pull, attach it to the slider and use pliers to tighten the top of the slider so the pull tab will not fall off.
Fix the coils, or teeth as they are often called, by gently sliding the slider back and forth across the damaged areas until they form back into the proper shape. If they are too heavily damaged to self-repair, use a small needle or pin to softly reshape each tooth.
Open the broken zipper all the way to the beginning of the duffel bag if the slider itself is worn or loose. Tighten it slightly with pliers so that it will not pop off after being zipped. Remove the slider completely with pliers if any part of it is broken. Replace it with a new slider of the same type.
Remove any materials that are caught in the zipper if the zipper becomes stuck. You can do this by gently pulling the material while holding the zipper in place. Pulling both violently may cause your zipper to break further. If only a small amount of material is jammed, you may be able to slide the slider right past it.
Clean the zipper teeth and slider if they become corroded and stick together. Use a mild soap with a soft toothbrush and water to gently scrub the zipper. Gently try to move it, and add a small amount of lubricant to help the zipper move. If it is too corroded to be cleaned, you may need to replace the slider or even the entire zipper.
Get a completely new zipper set if yours is torn and items can fall out of your bag. To attach it, carefully align both sides and sew them onto your bag. This is a difficult process best done by a professional repair technician. However, if only a slight tear is present in the zipper, you can stitch it up yourself.
Replacing an entire slider usually requires a visit to a repair shop.