Sikaflex 221 is a high-quality multi-purpose non-sag one-part polyurethane sealant that cures on exposure to atmospheric humidity to form a durable elastomer. Sikaflex 221 bonds well to a wide variety of substrates and is suitable for making permanent elastic seals of high adhesive strength. Suitable substrate materials are wood, metals, metal primers and paint coatings, ceramic materials and plastics. .
eBay