Solid tip: shortening a zipper
The Altair Project Bag calls for a 5GG (5-gauge, which describes the size of the teeth) metal zipper, 11" long from top stops to bottom stop. So what to do if you can't buy a zipper with those exact dimensions? You can, of course, change the dimensions of the bag to fit any zipper you own, but if you'd like to make the bag as originally designed, you can also shorten any zipper to fit the pattern. Here's how!
You will need:
A zipper longer than 11", a pair of sharp scissors, a ruler or measuring tape, a sharp hand-sewing needle, sewing thread to match your project, a pair of wire-cutting pliers or nippers, and eye protection of some kind (optional, but smart).
1. Cut the zipper to shape: Close the zipper. Cut off the extra zipper tape 1/2" above the top stoppers. Cut the zipper to the required length + 1/2" (measured from top stoppers to cutting point), being careful to cut between the teeth.
2. Add a new bottom "stopper": As you have just cut off the original bottom stopper, you will need to replace it. Since the zipper is going into a project right away, and won't be under stress before it's sewn into the Altair bag, the stopper doesn't need to be very strong; it's just a reminder to prevent the zipper pull from sliding off the zipper and rendering it useless! Simply thread a sharp hand-sewing needle with doubled regular sewing thread (to match your bag fabric color) and hand-sew a bar-tack across the zipper teeth at your desired stopping point, in this case, 11" from the top stops. 5 passes of the thread should be enough. Knot the ends of thread on the underside of the zipper and leave a 1" tail on each thread. This will make it easier to pull into a seam to hide the threads once the bag is assembled.
3. Put on your goggles and remove the excess zipper teeth: Using the pliers or nippers, remove the excess zipper teeth below the bar-tack one at a time, by cutting the tooth in half. The tooth may fly off in any direction when it's cut, so it's advisable to wear eye protection at this point. I find it easiest to work up the zipper tape from the cut edge toward the bar-tack holding the pliers diagonally, so that the blade crosses the tooth near the middle. Apply pressure until you can feel the tooth sever or bend. The tooth fragments usually fall off the tape on their own, but sometimes a tooth requires a few passes with the pliers. Continue in this fashion until you reach the bar-tack, being careful not to cut it with the pliers.
4. Apply your zipper to your Altair!
N. B.: You will notice that the tape in the above picture looks a little nibbled-upon; this may happen to your zipper as well. Don't worry, it will be hidden inside the bag construction and protected from further wear.