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SikaPower®-4508

Heat curing paint-shop adhesive and sealant

SikaPower®-4508 is a 1-component, cold-applied heat-curing adhesive and sealant based on flexibilized epoxy resin. As a sealant, it is especially designed for sealing on e-coated surfaces prior to a paint or powder-coating process.  

  • Adheres to e-coated and oily metal 
    substrates
  • Suitable for powder-coating processes
  • Good tooling properties
  • Compatible with spot welding
  • Does not contain solvents or PVC
 
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PRODUCT BENEFITS

  • Adheres to e-coated and oily metal 
    substrates
  • Suitable for powder-coating processes
  • Good tooling properties
  • Compatible with spot welding
  • Does not contain solvents or PVC
 

Areas of Application

SikaPower®-4508 can be used as an adhesive in combination with spot welding, riveting, clinching, and other mechanical fastening methods before the curing process is completed. It can bond oily substrates with a maximum of 3 g/m2. Due to the variety of oils, tests with original substrates and conditions are mandatory. SikaPower®-4508 works as well as a sealant on e-coated metals before subsquent paint processes (including powder-coating). 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
Chemical base

Epoxy-Polyurethane

Color (CQP001-1)

White

Density (uncured)

1.5 kg/l

Application temperature

20 – 50 °C

Curing conditions

at 180 °C

25 minutes

Tensile lap-shear strength (CQP046-9 / ISO 4587)

10 MPa A, B, C

Tensile strength (CQP580-5, -6 / ISO 527)

12 MPa C

Elongation at break (CQP580-5, -6 / ISO 527)

40 % C

Young's modulus (CQP580-5, -6 / ISO 527)

300 MPa C, D

Shelf life

9 months E

CQP = Corporate Quality Procedure

A) on 0.8 mm steel DC04

B) adhesive layer 0.3 mm

C) tested at 23 °C / 50 % r.h.D) elongation range 0.05 – 0.25 %E) stored at 5 – 25 °C
Technical Information

CURE MECHANISM

SikaPower®-4508 is cured by heat. The curing depends on both temperature and elapsed time. The most suitable heat sources are convection ovens. The minimum heating temperature is 160 °C, while the maximum must not exceed 220 °C.

It is highly recommended to perform tests with original parts to ensure proper curing and function of the bonded part under original conditions.

Application

Application Information

Application

In unipacks, SikaPower®-4508 can be applied with electric or pneumatic driven piston-operated guns. To improve application properties (extrusion force, cut-off string, etc.), it is recommended to heat up the unipack to 50 °C.

The adhesive can be applied in form of a round bead. If SikaPower®-4508 is used as an adhesive, join the parts as soon as possible to avoid moisture pick-up.

To avoid excess moisture uptake in an uncured state, which can lead to blistering, perform the curing process within 24 hours after the application. If not possible, perform a pre-curing process.

 

Pre-curing

To improve wash-out resistance SikaPower®-4508 shall be pre-cured for 5 minutes at 160 °C; to reduce moisture uptake (e.g., in case of shipping before full curing) or to reach handling strength the product shall be pre-cured for 15 minutes at 160 °C.

After the pre-curing process, complete the curing with a second heating process.

Overpainting tooling finishing

For tooling purposes, use small quantities of Sika® Tooling Agent N. The joint must be dry after the tooling and prior to the curing or pre-curing process.