When you need to waterproof a silnylon tent only a silicone sealant will work. Seam sealing with Seam Grip SIL is the best way to keep moisture out. This clear sealant dries to a silicone rubber that works on all silicone-treated gear such as a silnylon tarp or backpack. One tube seals up to 24’ of seams. Fast and easy to use, it’s also handy for repairing pinholes and small tears. Remember: only silicone will adhere to silicone, so treat your gear right with Seam Grip SIL.