It can be annoying when the zipper on your favorite clothing breaks apart. Joining two zippers may seem difficult but there are ways make it a success. With the right tools, you can fix your clothing or accessory and maintain the structure of your garment.
Remove the old zipper stop from the zipper that has separated. The stop is the small horizontal piece that is on the bottom of the zipper (it stops the slider, when zipping down). Use pliers to pull apart the zipper stop; it should be easy to pull apart.
Take the slider down the zipper and run the two sides of the zipper back into the slider, by fitting the teeth into each other. The teeth are the small metal pieces that make up the zipper. This will realign the slider and the two sides of the zipper. Zip the zipper up, to ensure that it is aligned properly.
Create a new zipper stop with a needle and thread. Thread a needle with thick thread, in any color you desire. You can get thick thread from your nearest arts and crafts store or fabric shop. Sew several stitches (as you would sew any other piece of clothing) at the bottom of the zipper, starting from the backside. You need enough stitches to prevent the slider from coming off but not so many that it becomes bulky.
Make two knots to tie off the zipper stop. Make sure the knots are secure so the stop does not unravel. Cut off the excess thread.