1. Resin zippers often lose teeth.
2. Check the position of bad teeth or missing teeth. If the position is close to the end, it can still be repaired, but if it is close to the beginning, be prepared to replace the resin zipper. If the missing tooth is in the back third of the entire resin zipper, you can fix it.
3. If it is in the first two thirds, you should replace the entire resin zipper.
4. Pull the zipper to the top of the bad tooth. You can pull the zipper all the way up or just over the bad tooth. As long as it is on the bad tooth, it doesn't really matter where it is.
5. Sew a few stitches on the bad tooth. Sew at least six stitches to create a new end. You'll need to sew a few more times, it's more secure.
6. The new end should be just above the damaged part so that more resin zipper remains.
7. Both sides of the teeth should be sewn.
8. Check the resin zipper. The zipper should pull all the way from the beginning to the new end.