How to Repair School Bag Damage: Zippers, Straps, Buckles, and Holes By Chester Takau · July 2026 Most school bag damage falls into five categories, and four of them are fixable in under twenty minutes without a sewing machine: a zipper that won't stay closed (usually the slider, not the teeth), a strap where the stitching has torn out, a snapped plastic buckle, and a hole or worn corner in the fabric. The fifth — a delaminated waterproof lining or a broken frame — is where replacing the bag actually makes more sense than fixing it. Below is a card for each failure, in the order students and parents usually run into them. 1 The zipper slides but pops open behind the pull — is it broken? Almost never. If the teeth are intact and the gap opens up a few inches behind where the pull tab sits, the slider itself has widened with wear and stopped gripping the teeth. Updated 2026 repair guides agree on the fix: squeeze the back of the slider gently with pliers...