Sikasil® AS-785 is especially designed for fast and/or automated bonding of structural adhesive joints. Especially for interior or exterior applications where a high mechanical performance under harsh conditions are required, like in appliances, solar and automotive. Common substrates are metals, particularly aluminum, glass, metal primers and paint coatings (2-part systems), ceramic materials and plastics. 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

Typical Product Data

Properties

Sikasil® AS-785 (A)

Sikasil® AS-785 (B)

Chemical base

2-component silicone

Color (CQP001-1)

mixed

White	Black
Black

Cure mechanism

Polycondensation

Cure type

Alkoxy

Density (uncured)

mixed

1.38 kg/l	1.06 kg/l
1.35 kg/l

Mixing ratio

A:B by volume

A:B by weight

10:1

13:1

Viscosity (CQP029-6)

at 0.89 s^-1

1700 Pa·s

400 Pa·s

Consistency

Paste

Application temperature

ambient

5 ─ 40 °C

Snap time (CQP554-1)

12 minutes ^{A, B}

Tack free time (CQP019-3)

40 minutes ^A

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

Tensile strength (CQP036-1 / ISO 527)

2 MPa

100 % modulus (CQP036-1 / ISO 527)

1.2 MPa

Elongation at break (CQP036-1 / ISO 527)

250 %

Service temperature (CQP513-1)

-40 ─ 150 °C

Shelf life (CQP016-1)

15 months ^C

9 months ^C

CQP = Corporate Quality Procedure

^A) 23 °C / 50 % r. h.

^B) The snap time can increase add. 6 min. with component B at the end of shelf life

^C) storage below 25 °C

Technical Information

CURE MECHANISM

Sikasil® AS-785 starts to cure immediately after mixing the two 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 could lead to bubble formation and is therefore not allowed.
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

Before processing Sikasil® AS-785 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.

Tooling and finishing

Tooling and finishing must be carried out within the snap time of the adhesive. No tooling agents must be used.

Removal

Uncured Sikasil® AS-785 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

Sikasil® AS-785 cannot be overpainted

Application limits

To exclude materials influencing Sikasil® AS-785, 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.
Sikasil® AS-785 may only be used for serial application after a detailed examination and written approval of the corresponding project details by Sika Industry.