Sikaflex®-527 AT
Isocyanate free sealant with reduced substrate preparation
Sikaflex®-527 AT is a 1-component Silan Terminated Polymer (STP) sealant that cures at exposure to atmospheric humidity. It is made for multipurpose elastic joints for interior and exterior of the vehicle body. Sikaflex®-527 AT adheres well to most materials commonly used in body shop.
- Fast curing
- Excellent working properties
- Over paintable with water-based paint systems
- Good adhesion to a wide variety of substrates without primer
- Ageing and weathering resistant
- Low odor
- Non-corrosive
- Solvent and isocyanate-free
- Silicone and PVC-free
PRODUCT BENEFITS
- Fast curing
- Excellent working properties
- Over paintable with water-based paint systems
- Good adhesion to a wide variety of substrates without primer
- Ageing and weathering resistant
- Low odor
- Non-corrosive
- Solvent and isocyanate-free
- Silicone and PVC-free
Usage
Sikaflex®-527 AT is suitable for sealing, seam sealing, simple bonding as well as for vibration reduction and sound dampening measures in collision repair and vehicle body construction. It adheres well to most the materials commonly used in body shops, e.g. metal primers and paint coatings, metals, painted plastics and plastics. Seek manufacturer’s advice and perform tests on original substrates before using Sikaflex®-527 AT 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.Packaging
| Cartridge | 300 ml |
| Unipack | 400 ml |
| Drum | 195 l |
Product Details
| Chemical base | Silane Terminated Polymer | |
| Color (CQP001-1) | White, black, light grey | |
| Cure mechanism | Moisture-curing | |
| Density (uncured) | (depending on color) | 1.4 kg/l |
| Non-sag properties | Good | |
| Application temperature | ambient | 5 ─ 40 °C |
| Skin time (CQP019-1) | 40 minutes A | |
| Curing speed (CQP049-1) | (see diagram) | |
| Shrinkage (CQP014-1) | 3 % | |
| Shore A hardness (CQP023-1 / ISO 7619-1) | 40 | |
| Tensile strength (CQP036-1 / ISO 527) | 1.5 MPa | |
| Elongation at break (CQP036-1 / ISO 527) | 400 % | |
| Tear propagation resistance (CQP045-1 / ISO 34) | 6 N/mm | |
| Service temperature (CQP513-1) |
4 hours 1 hour | -50 ─ 80 °C 120 °C 160 °C |
| Shelf life (CQP016-1) | cartridge unipack drum | 15 months B 12 months B 9 months B |
CQP = Corporate Quality Procedure | A) 23 °C / 50 % r. h. | B) storage below 25 °C |
CURE MECHANISM
Sikaflex®-527 AT 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 Sikaflex®-527 AT
CHEMICAL RESISTANCE
Sikaflex®-527 AT 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, dust and contaminants.
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®-527 AT can be processed between 5 °C and 40 °C but changes in reactivity and application properties have to be considered. The optimum temperature for substrate and sealant is between 15 °C and 25 °C.
Sikaflex®-527 AT can be processed with hand, pneumatic or electric driven piston guns.
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®-527 AT 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 Sika® Cleaner-350H cleaning towels or a suitable industrial hand cleaner and water.
Do not use solvents on skin.
Overpainting
Sikaflex®-527 AT can be best painted within the skin formation time. If painting process takes place after the sealant has built a skin, adhesion could be improved by treating the joint surface with Sika®Aktivator-100 or Sika®Aktivator-205 prior to paint process. If the paint requires a baking process (> 80 °C), best performance is achieved by allowing the sealant to fully cure first. 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.