Sikasil® WT-489

High-performance, two-part industrial window bonding silicone

Sikasil® WT-489 is a two-part, neutral-curing, and fast-setting silicone sealant and adhesive suitable for structural bonding of insulating glass units into window frames, back-bedding and heel or toe bead applications.

Designed for adhesion to a wide variety of substrates
Compatible with traditional insulating glass edge sealing systems
Very good mechanical properties for window bonding applications
Optimized application properties for improved productivity of automated mix and dispense equipment
Superior UV and weathering resistance
Remains flexible over a wide temperature range
Long-term durability

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Product Data Sheet Show all documents

PRODUCT BENEFITS

Designed for adhesion to a wide variety of substrates
Compatible with traditional insulating glass edge sealing systems
Very good mechanical properties for window bonding applications
Optimized application properties for improved productivity of automated mix and dispense equipment
Superior UV and weathering resistance
Remains flexible over a wide temperature range
Long-term durability

Usage

Sikasil® WT-489 has a wide adhesion range on many substrates such as glass, (coated) metal, wood, PVC and many other substrates. In combination with its good mechanical properties, this makes the adhesive suitable for structural bonding of insulating glass units into window frames and for back-bedding applications. It is further suitable for demanding industrial bonding and sealing 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

Sikasil® WT-489 (A)

Drum	197 kg (52 gal)

Sikasil® WT-489 (B)

Pail	20 kg (5 gal)

Product Details

Typical Product Data

Properties

Component A

Sikasil® WT-489

Component B

Sikasil® WT-489

Chemical base

2-component silicone

Color (CQP001-1)

mixed

White	Black
Grey

Cure mechanism

Polycondensation

Cure type

Alkoxy

Density (uncured)

mixed

1.31 kg/l (10.93 lbs/gal)	1.05 kg/l (8.76 lbs/gal)
1.28 kg/l (10.68 lbs/gal)

Mixing ratio

A:B by volume
A:B by weight

10:1
12:1

Viscosity (CQP029-5 / ISO 3219)

675 Pa·s

600 Pa·s

Consistency

Paste

Application temperature

ambient

5 ─ 40 °C (41 ─ 104 °F)

Snap time (CQP554-1)

10 minutes ^A

Tack free time (CQP019-3)

40 minutes ^A

Shore A hardness (CQP023-1 / ISO 48-4)

7 days curing at 23 °C / 50 % r.h.

Tensile strength (CQP036-1 / ISO 527)

1.8 MPa (260 psi)

100 % modulus (CQP036-1 / ISO 527)

0.89 MPa (130 psi)

Elongation at break (ASTM D412)

230 %

Service temperature (CQP513-1)

-40 ─ 150 °C (-40 ─ 302 °F)

Shelf life

15 months ^B

9 months ^B

CQP = Corporate Quality Procedure

^A) 23 °C (73 °F) / 50 % r. h.

^B) stored below 25 °C (77 °F)

Technical Information

CURE MECHANISM

Sikasil® WT-489 starts to cure immediately after mixing the 2-components.
The speed of the reaction depends mainly on the temperature, i.e. the higher the temperature the faster the curing process. Heating above 50 °C (122 °F), as this could lead to bubble formation.
The mixer open time, i. e. the time the material can remain in the mixer without flushing or extrusion of product, is significantly shorter than the snap time indicated above.

Application

Application Information

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 process material is between 15 °C and 25 °C (59 °F and 77 °F).
Before processing Sikasil® WT-489 both components have to be mixed homogeneously and air-bubble-free in the correct ratio as indicated with an accuracy of ±10 %. Most commercially available metering and mixing equipment are suitable. For advice on selecting and setting up a suitable pump system, contact the System Engineering Department of Sika Industry.
Consider that the B-component is moisture-sensitive and must therefore only be exposed briefly to air.
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.

Tooling and finishing

Tooling and finishing must be carried out within the snap time of the adhesive.
When tooling freshly applied Sikasil® WT-489, press the adhesive to the joint flanks to get a good wetting of the bonding surface. No tooling agents must be used.

Removal

Uncured Sikasil® WT-489 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-489 cannot be overpainted.

Application Limits

To exclude materials influencing Sikasil® WT-489, all materials such as gaskets, 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.
The above mentioned Sika process materials may only be used in structural glazing or window bonding applications after a detailed examination and written approval of the corresponding project details by Sika Industry.