Sikaflex 221 is a one component, high-quality multipurpose non-sag 1-c formulated polyurethane sealant that cures on exposure to atmospheric humidity to form a durable elastomer. Sikaflex 221 polyurethane sealant is elastic, emits a low odor and is resistant to weathering exposure. Sikaflex 221 series sealant is non-corrosive, can be overpainted and sanded, possesses lower VOC’s, and is NSF registered and approved for incidental food contact and potable water. Sikaflex 221 bonds well to many types of substrates and is suitable for making permanent elastic seals of high adhesive strength. Some of these suitable substrate materials are wood, metals, metal primers and paint coatings (2-c systems), ceramic materials and plastics. Before using on transparent and pigmented materials that are prone to stress cracking, contact the Technical Service Department of Sika Industry at firstname.lastname@example.org. Sikaflex 221 is resistant to fresh water, seawater, limewater, sewage effluent, diluted acids and caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, alcohol, concentrated mineral acids and caustic solutions or solvents. This chemical resistance information is offered for general guidance only. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed to ensure adhesion and material compatibility.
Avoid application below 41°F and above 104°F.
Do not apply on frozen or wet surfaces or through standing water.
Do not apply over silicones or silane-terminated polymer sealants or in the presence of curing silicones or silane terminated polymer sealants
Contact with alcohol or alcohol containing solvents will prevent cure