Sikaflex®-216
Sikaflex®-216 is a high-quality multipurpose low viscous 1-component polyurethane sealant that cures on exposure to atmospheric humidity. It is specifically designed for sealing applications that need to be performed prior the paint shop. Sikaflex®-216 has very good tooling properties.
• Bonds well to a wide variety of substrates
• Easy to brush
• Low odor
• Non-corrosive
• Very low VOC
• Silicone free and solvent free
PRODUCT BENEFITS
• Good overpaintability
• Bonds well to a wide variety of substrates
• Easy to brush
• Low odor
• Non-corrosive
• Very low VOC
• Silicone free and solvent free
Areas of Application
Sikaflex®-216 bonds well to a wide variety of substrates and is used for permanent elastic seals. It is designed for sealing applications of chassis and body structures (prior to paint shop) in the transportation industry.It is applied in bead form and due to the low viscosity it can be easily brushed or smoothed to get the desired finish. Seek manufacturer’s advice and perform tests on original substrates before using Sikaflex®-216 on materials prone to stress cracking. This product is suitable for experienced professional users only. Tests with actual substrates and conditions have to be performed ensuring adhesion and material compatibility.
Product Details
| Chemical base | 1-component polyurethane | |
| Color (CQP001-1) | Steel grey, black | |
| Cure mechanism | Moisture-curing | |
| Density (uncured) | 1.29 kg/l | |
| Application temperature | ambient | 10 ─ 40 °C |
| Skin time (CQP019-1) | 40 minutes A | |
| Curing speed (CQP049-1) | (see diagram) | |
| Shrinkage (CQP014-1) | 2 % | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 30 | |
| Tensile strength (CQP036-1 / ISO 527) | 1.5 MPa | |
| Elongation at break (CQP036-1 / ISO 527) | 600 % | |
| Tear propagation resistance (CQP045-1 / ISO 34) | 8 N/mm | |
| Service temperature (CQP513-1) |
1 hour | -50 ─ 80 °C 140 °C |
| Shelf life | 12 months B |
CQP = Corporate Quality Procedure | A) 23 °C / 50 % r. h. | B) storage below 25 °C |
CURE MECHANISM
Sikaflex®-216 cures by reaction with atmospheric moisture. At low temperatures the water content of the air is generally lower and the curing reaction proceeds somewhat slower (see diagram 1).
Diagram 1: Curing speed for Sikaflex®-216
CHEMICAL RESISTANCE
Sikaflex®-216 is generally resistant to fresh water, seawater, diluted acids and diluted caustic solutions; temporarily resistant to fuels, mineral oils, vegetable and animal fats and oils; not resistant to organic acids, glycolic alcohol, concentrated mineral acids and caustic solutions or solvents.
Application
Surface preparation
Surfaces must be clean, dry and free from grease, oil and dust.
Surface treatment depends on the specific nature of the substrates and is crucial for a long lasting bond. Suggestions for surface preparation may be found on the current edition of the appropriate Sika® Pre-Treatment Chart. Consider that these suggestions are based on experience and have in any case to be verified by tests on original substrates.
Application
Sikaflex®-216 can be processed between 10 °C and 40 °C but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and process material is between 15 °C and 25 °C.
Sikaflex®-216 can be processed with manual, pneumatic or electric driven piston guns as well as pump equipment.
For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Tooling and finishing
Tooling and finishing must be carried out within the skin time of the sealant. It is recommended using Sika® Tooling Agent N. Other finishing agents must be tested for suitability and compatibility prior the use.
Removal
Uncured Sikaflex®-216 can be removed from tools and equipment with Sika® Remover-208 or another suitable solvent. Once cured, the material can only be removed mechanically. Hands and exposed skin have to be washed immediately using hand wipes such as Sika® Cleaner-350H or a suitable industrial hand cleaner and water.
Do not use solvents on skin!
Overpainting
Sikaflex®-216 can be painted after formation of a skin. If the paint requires a baking process, best performance is achieved by allowing the sealant to fully cure first. 1C-PUR and 2C-acrylic based paints are usually suitable. All paints have to be tested by carrying preliminary trials under manufacturing conditions.
The elasticity of paints is usually lower than that of sealants. This could lead to cracking of the paint in the joint area.