We sell and use lots of tents and waterproof gear.  When seams leak or the waterproof seam tape starts to peal, we like Seam Grip Seam Sealer.  The Seam Grip SIL is a sealant specifically designed for silicone treated fabrics, perfect for sealing silnylon tents, tarps and ultralight backpacks. A single 1.5 oz tube can seal up to 24 ft of seams, perfect for pinhole repairs and small tears, easy to use and weather-resistant. Keeps gear waterproof in extreme heat or cold. 

• Compatible – Bonds to silicone treated fabrics to prevent water from seeping through seams
• Waterproof – Provides a water-tight seal that won’t peel or crack over time, keeping you warm and dry
• Long-lasting – Rubber sealant seals seams and patches pinhole leaks for repairs that last for years
• Flexible – Cures to an elastic, rubber seal that flexes and stretches with high performance gear
• Weather-resistant – Tough formula is not affected by extreme heat or cold
• 1.5 oz tube