Sikasil® WT-121 LUM
Self-leveling, narrow joint silicone sealant with luminescent pigment
Sikasil® WT-121 LUM is a self-leveling, one component, neutral cure silicone sealant, which is especially suitable for window fabrication. For in-process quality control purposes, Sikasil® WT-121 LUM contains a luminescent pigment that aids in identifying the presence of the sealant using UV light.
- Meets the requirements of AMAA 803.3
- Luminescent pigment for UV tracing
- Faster production capability in assembly processes
- Designed for flexibility in dynamic joint movement
- Superior UV and weathering resistance
- Bonds to most substrates without priming
- Compatible with IG sealants
Sikasil® WT-121 LUM
SELF LEVELING, LUMINESCENT SILICONE SEALANT
Especially suitable for window fabrication, Sikasil® WT-121 LUM contains a luminescent pigment that aids in identifying the presence of the sealant using UV light. This allows for faster production capability in assembly processes.
PRODUCT BENEFITS
- Meets the requirements of AMAA 803.3
- Luminescent pigment for UV tracing
- Faster production capability in assembly processes
- Designed for flexibility in dynamic joint movement
- Superior UV and weathering resistance
- Bonds to most substrates without priming
- Compatible with IG sealants
Usage
Sikasil® WT-121 LUM has a wide adhesion range on many substrates such as glass, (coated) metal, wood, PVC and many other substrates. Sikasil® WT-121 LUM is suitable to be used as a sealant for window / door fabrication, small joints, miter joints, screw heads, and general component assembly applications. 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
| Drum | 52 gal |
Product Details
| Chemical base | 1-component silicone | |
| Color (CQP001-1) | Translucent | |
| Cure mechanism | Moisture-curing | |
| Cure type | Neutral | |
| Density (uncured) | 0.98 kg/l | |
| Application temperature | ambient | 5 ─ 40 °C (41 ─ 104 °F) |
| Skin time (CQP019-1) | 20 minutes A | |
| Tack free time (CQP019-3) | 48 minutes A | |
| Curing speed (CQP049-1) | (see diagram 1) | |
| Shore A hardness (CQP023-1 / ISO 48-4) | 21 days curing at 23 °C (73 °F) / 50 % r.h. | 20 |
| Tensile strength (ASTM D412) | 0.5 MPa (70 psi) | |
| Elongation at break (ASTM D412) | 350 % | |
| Service temperature | -40 ─ 150 °C (-40 ─ 302 °F) | |
| Shelf life | 12 months B |
| CQP = Corporate Quality Procedure | A) 23 °C (73 °F) / 50 % r.h. | B) stored below 25 °C (77 °F) |
CURE MECHANISM
Sikasil® WT-121 LUM 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 of Sikasil® WT-121 LUM
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.
Application
The optimum temperature for substrate and sealant is between 15 °C and 25 °C (59 °F and 77 °F).
Sikasil® WT-121 LUM can be processed with pump equipment. For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Joints must be properly dimensioned.
Basis for calculation of the necessary joint dimensions are the technical values of the adhesive and the adjacent building materials, the exposure of the building elements, their construction and size as well as external loads.
Joints deeper than 15 mm (9/16 in.) must be avoided.
Tooling and finishing
Tooling and finishing must be carried out within the skin time of the sealant or adhesive. When tooling freshly applied Sikasil® WT-121 LUM press the adhesive to the joint flanks to get a good wetting of the bonding surface. No tooling agents to be used.
Removal
Uncured Sikasil® WT-121 LUM may 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 or a suitable industrial hand cleaner and water.
Do not use solvents on skin.
Overpainting
Sikasil® WT-121 LUM cannot be overpainted.
Application Limits
Recommended solution from Sika for structural glazing and window bonding are usually compatible to each other. These solutions consist of products such as Sikasil® SG, IG, WS and WT series. For specific information regarding compatibility between various Sikasil® products and other Sika products contact the Technical Department of Sika Industry.
To exclude materials influencing Sikasil® WT-121 LUM, all materials such as gaskets, tapes, setting blocks, sealants, etc., in direct and indirect contact have to be approved by Sika in advance.
Where two or more different reactive sealants are used, allow the first to cure completely before applying the next one.
Do not use Sikasil® WT-121 LUM on PMMA and PC elements as it may cause environmental stress cracking (crazing).