Minor weave separation – If the woven fibers or yarns of the fabric have just separated slightly, you may be able to lightly massage the individual fabric fibers back into place. Just work the fabric a bit between your thumb and fingers to see if the yarns go back into place.
Small pinholes – If there are just a few of the fibers actually tore or broken in two, you can rub in a very small dab of McNett’s Seam Grip on the spot and massage it into the fabric. I use a plastic baggie to keep the stuff off my fingers, but you can use rubber gloves if you have them. Leave the repaired spot uncovered to dry in a well ventilated area. Another product that will get you by if you need to do a minor repair out in the woods is to apply a small piece of McNett’s Tenacious Tape to one or both sides.
Holes or small tears – If the fibers are torn and you have larger holes in the fabric, it’s best to add a small patch of fabric to both sides. In addition to working the Seam Grip into the fabric, use some to coat 2 small round pieces of fabric and smash them together over both sides of the damaged area. Let it dry and keep a close eye on it from now on. To prevent any sticky spot, you can lightly dust it with baby powder.
I haven’t personally tried it, but folks say you can do this exact same thing with a product called Permatex Flowable Windshield Sealer. If you’re in a rush, this may be easier to buy at any of your local car parts stores.
Here is a good video from UGQ Outdoor showing a similar process except they are using seam sealer instead of Seam Grip. This video also shows the powdering step at the end. https://www.youtube.com/watch?