Description of McNett Seam Grip® Seam Sealer & Outdoor Repair 1oz Seam Grip® Seam Sealer & Outdoor Repair is a waterproof, flexible urethane formula for use in repairing surfaces or sealing seams of natural and synthetic fabrics, waterproof laminates, leather and vinyl. SEAMGRIP may be used to repair all types of waders and footwear, neoprene, PVC, rubber, and more. Concentrated and waterproof, SEAMGRIP offers excellent adhesion, long lasting flexibility, superior traction and abrasion resistance, with minimal shrinkage.