3M™ Scotch-Weld™ Epoxy Adhesive DP490
- 90-minute work life supports complex assembly positioning and alignment
- Maintains bond strength across high- and low-temperature operating conditions
- Bonds metals, composites, glass, ceramics, plastics, and wood
Product Description
3M Scotch-Weld Epoxy Adhesive DP490 Black
3M™ Scotch-Weld™ Epoxy Adhesive DP490 Black is a non-sag, thixotropic, two-component structural epoxy adhesive developed for high-strength bonding applications requiring exceptional toughness, environmental durability, and elevated temperature performance.
Formulated for demanding transport, rail, aerospace, and industrial assembly applications, DP490 mixes at a 2:1 volume ratio (Part A to Part B) and provides a 90-minute work life at 73°F (23°C), allowing extended time for positioning, alignment, and adjustment on large or complex assemblies. The adhesive typically reaches handling strength within 4 to 6 hours and achieves full cure in 7 days at room temperature.
Key Properties
Toughened epoxy formulation for high impact and fatigue resistance
High shear and peel strength for durable structural bonding performance
90-minute work life supports complex assembly positioning and alignment
Non-sag, thixotropic consistency suitable for vertical and overhead applications
Maintains bond strength across high- and low-temperature operating conditions
Bonds metals, composites, glass, ceramics, plastics, and wood
Excellent gap-filling capability for assemblies with uneven surfaces or variable fit-up tolerances
Available in Duo-Pak cartridges and bulk packaging formats for scalable production use
Typical Applications
Structural bonding of rail car interior panels, flooring systems, and composite assemblies
Automotive body assembly, panel bonding, and stiffener attachment requiring elevated temperature resistance
Composite bonding in aerospace, marine, and industrial manufacturing applications
Bonding plastics and powder-coated metal components in transportation and equipment assembly
Gap-filling structural bonds where surface flatness or dimensional tolerances are inconsistent
Vertical and overhead bonding applications requiring non-sag adhesive performance
High-temperature service environments where standard epoxy adhesives may not maintain sufficient bond strength
Technical Specifications
| General Properties | |||||
| Color Color The color | Black/Off-White | ||||
| Mix Ratio Mix Ratio The amount of a constituent divided by the total amount of all other constituents in a mixture | 2:1 | ||||
| Specific Gravity Specific Gravity Specific gravity (SG) is the ratio of the density of a substance to the density of a reference substance; equivalently, it is the ratio of the mass of a substance to the mass of a reference substance for the same given volume. For liquids, the reference substance is almost always water (1), while for gases, it is air (1.18) at room temperature. Specific gravity is unitless. | 1.00 | ||||
| Work life @25°C Work life @25°C Work life is the amount of time we have to work with a material until it is no longer able to be easily worked and applied on a substrate. It is based on the change in viscosity and it can rely on the application requirements. | 1.5 hours | ||||
| Curing Conditions | |||||
| |||||
Additional Information
3M™ Scotch-Weld™ Epoxy Adhesive DP490 Black
Non-sag, thixotropic two-part structural epoxy with 90-minute work life, outstanding temperature resistance, and gap-filling capability for demanding transport, rail, and industrial bonding applications.
3M™ Scotch-Weld™ Epoxy Adhesive DP490 Black is a non-sag, thixotropic, two-component structural epoxy adhesive formulated for high-toughness bonding applications that demand both strength and environmental durability. Mixed at a 2:1 volume ratio (Part A to Part B), DP490 delivers a 90-minute work life at 73°F (23°C), providing ample time for positioning and adjustment on large or complex assemblies. Handling strength is typically reached in 4 to 6 hours, with full cure achieved in 7 days at room temperature.
DP490 is specifically designed for applications requiring a combination of toughness, gap-filling performance, and sustained bond strength under heat and environmental exposure. It maintains excellent shear and peel strength up to 248°F (120°C), making it well suited to rail, automotive, and heavy industrial assemblies that are exposed to elevated service temperatures. The thixotropic, non-sag formulation allows the adhesive to be applied to vertical and overhead surfaces without slumping before the bond is closed. DP490 bonds a particularly wide range of substrates including most plastics and powder-coated metals that are difficult for many other structural adhesives. Available in 50 mL and 400 mL Duo-Pak cartridges for EPX applicator dispensing and in an 18-liter bulk format for high-volume production.
Non-sag thixotropic formula for vertical and overhead applications
DP490 is formulated with thixotropic rheology, meaning it resists flow under its own weight when at rest but flows readily under shear during application. This non-sag behavior allows the adhesive to be applied to vertical and overhead surfaces without slumping or running before the assembly is closed, broadening the range of joint orientations it can be used in without additional fixturing.
Gap-filling capability accommodates surface irregularities and tolerance variation
The gap-filling properties of DP490 allow it to bridge surface irregularities, machining tolerances, and fit-up gaps in the bond line without the need for shimming or precise surface matching. This is particularly valuable in composite and metal assemblies where surface flatness cannot always be guaranteed across the full bond area.
Outstanding temperature resistance up to 248°F (120°C)
DP490 retains excellent shear and peel strength at elevated temperatures up to 248°F (120°C), making it suitable for assemblies that operate at sustained high temperatures or are subjected to repeated thermal cycling in service. This thermal performance is significantly higher than that of many standard structural epoxies and makes DP490 a reliable choice for under-hood automotive components, rail interiors, and industrial equipment.
90-minute work life for complex and large-area assemblies
With a 90-minute work life at 73°F (23°C), DP490 gives operators generous time to apply adhesive, position substrates, and make alignment corrections before the adhesive begins to set. This extended open time is particularly beneficial on large bonded surfaces or complex assemblies where a shorter work life would require multiple adhesive applications or rushed part positioning.
Bonds most plastics and powder-coated metals
DP490 achieves strong adhesion to a wide range of substrates including most plastics and powder-coated metal surfaces that are typically challenging for structural epoxy adhesives. This broad substrate compatibility reduces the need to use different adhesive products for different material combinations in mixed-substrate assemblies, particularly in rail car interiors and automotive body assemblies where painted and coated surfaces are common.
Excellent environmental and chemical resistance after full cure
DP490 exhibits strong resistance to environmental aging, humidity, and a range of industrial chemicals after full cure. Testing confirms that bonds retain a high percentage of their room-temperature shear strength after exposure to elevated temperature, humidity, fuel, and other fluids encountered in automotive and rail service environments, supporting long-term bond durability in demanding in-service conditions.
Why DP490 Is Suited to High-Demand Transport and Industrial Bonding
DP490 addresses a specific set of bonding challenges that are common in rail, automotive, and heavy industrial manufacturing: large assemblies that need extended working time, joints that must perform at high temperatures, surfaces that are difficult to bond, and bond lines that cannot always be perfectly fit-up. Most structural epoxies require a compromise across these requirements. DP490 is formulated to meet all of them simultaneously.
High-temperature service requirements eliminate many standard epoxies
Many structural epoxy adhesives begin to lose significant bond strength above 80°C to 100°C. In rail and automotive applications, under-body and under-hood components regularly reach or exceed these temperatures. DP490 is formulated to maintain excellent shear and peel strength up to 120°C, extending the useful service range of bonded joints into environments where other structural adhesives would be unsuitable.
Powder-coated and painted surfaces require specialist adhesive selection
Many structural adhesives achieve their rated strength on bare metal but perform significantly worse on painted, powder-coated, or treated surfaces because adhesion depends on the coating rather than the substrate. DP490 is specifically designed to bond these difficult surfaces, allowing manufacturers to bond components after surface coating operations without stripping coatings from the bond area.
Non-sag formula enables bonding in orientations that other adhesives cannot
Liquid or low-viscosity adhesives flow out of vertical and overhead joints before the assembly can be closed and fixtured, leading to starved bond lines and weak joints. DP490's thixotropic rheology ensures the adhesive stays where it is applied, enabling consistent bond line geometry on vertical panels, overhead joints, and complex assembly orientations without the need for additional tooling or temporary fixturing to hold the adhesive in place.
Application Spotlight
Structural Bonding for eMobility
High-temperature resistant structural adhesives like DP490 are increasingly used in eMobility platforms, from battery enclosure bonding and busbar assembly to structural joints in electric bus and rail car bodies. Learn how structural bonding solutions are being applied in eMobility design and manufacturing.
Packaging Options
DP490 Black is available in four packaging configurations to match different dispensing methods and production volumes. Duo-Pak cartridges are dispensed using the 3M EPX applicator system with an EPX Mixing Nozzle (sold separately). The bulk 18-liter format is intended for use with automated proportioning and dispensing equipment.
50 mL Duo-Pak Cartridge
For use with the 3M Scotch-Weld EPX Plus II Manual Applicator. Suited to low-volume bonding, repair, prototyping, and maintenance tasks where smaller quantities of adhesive are needed per session. Compatible with 3M EPX Mixing Nozzles for 50 mL cartridges at 2:1 mix ratio.
400 mL Duo-Pak Cartridge
For use with the 3M Scotch-Weld EPX Dual Drive 400 mL Manual or Pneumatic Applicator. Suited to medium to higher-volume production bonding where more adhesive is dispensed per cartridge before a changeover. Compatible with 3M EPX Mixing Nozzles for 400 mL cartridges at 2:1 mix ratio.
400 mL Duo-Pak Cartridge — US/Canada Label, 6 per Case
400 mL Duo-Pak with US/Canada regulatory label, supplied in cases of 6. For use with the 3M Scotch-Weld EPX Dual Drive 400 mL Manual or Pneumatic Applicator. The case format is suited to production environments that require stocked quantities of this cartridge size for sustained manufacturing operations. Compatible with 3M EPX Mixing Nozzles for 400 mL cartridges at 2:1 mix ratio.
Part A — 18 L Bulk
Part A supplied in an 18-liter bulk container for high-volume production use with automated two-component proportioning and dispensing equipment. Must be combined with the corresponding Part B at the correct 2:1 volume ratio. Intended for facilities with established bulk adhesive dispensing infrastructure. Contact 3M or your distributor for Part B supply options and dispensing equipment guidance for this format.
Application Spotlight
Structural Bonding for eMobility
Structural adhesives like DP420 play a critical role in eMobility assemblies, from battery enclosure bonding and thermal interface attachment to lightweight multi-material structures in electric vehicles. Learn how structural bonding solutions are being applied in eMobility design and manufacturing.
Technical Specifications
Uncured Properties
| Property | Value |
|---|---|
| Adhesive Type | Toughened, thixotropic two-part epoxy |
| Color (mixed) | Black |
| Mix Ratio (Volume) | 2:1 (Part A : Part B) |
| Rheology | Non-sag, thixotropic, gap-filling |
| Work Life at 73°F (23°C) | Approximately 90 minutes |
Cured Properties
| Property | Value |
|---|---|
| Handling Strength | 4 to 6 hours at 73°F (23°C) |
| Full Cure | 7 days at room temperature |
| Shear Strength | Up to approximately 30.2 N/mm² |
| Peel Strength | Up to approximately 12.7 daN/cm |
| Max Service Temperature | 248°F (120°C) |
| Environmental Resistance | Excellent (humidity, fuel, thermal cycling) |
Compatible Substrates
DP490 bonds effectively to the following substrate categories when surfaces are properly prepared:
- Steel and stainless steel
- Aluminum and other metals
- Powder-coated and painted metals
- Carbon fiber (CFRP) and composites
- Most engineering plastics
- Glass and ceramics
Bond strength on specific substrates depends on surface preparation, bondline thickness, and cure conditions. Always test on actual production substrates before committing to final assembly parameters. Refer to the DP490 Technical Data Sheet for substrate-specific strength data.
Recommended Dispensing Equipment
- 50 mL Duo-Pak: 3M™ Scotch-Weld™ EPX Plus II Manual Applicator with 1:1/2:1 plunger and EPX Mixing Nozzle (50 mL, square or helical)
- 400 mL Duo-Pak: 3M™ Scotch-Weld™ EPX Dual Drive 400 mL Manual or Pneumatic Applicator with EPX Mixing Nozzle (400 mL, square or helical)
- 18 L bulk: Two-component automated proportioning and dispensing equipment capable of maintaining a 2:1 volume ratio. Contact 3M for equipment recommendations.
Surface Preparation
Bond strength with DP490 is directly affected by the cleanliness and condition of substrate surfaces before adhesive application. For high-strength structural bonds, all paint, oxide films, oils, dust, mold release agents, and other contaminants must be removed from the bond area before applying the adhesive.
Bare Metal Substrates
- Solvent wipe bonding surfaces with isopropyl alcohol (IPA) or an equivalent degreaser to remove oils and surface contamination. Wipe in one direction with a clean, lint-free cloth.
- Lightly abrade with fine-grit abrasive paper or a Scotch-Brite pad to remove surface oxides and improve mechanical adhesion.
- Wipe again with IPA after abrasion to remove abrasive particles and contamination generated during the process.
- Apply adhesive immediately. Do not allow prepared surfaces to be contaminated or touched with bare hands before bonding.
Powder-Coated, Painted, Composite, and Plastic Substrates
- Solvent wipe bonding surfaces with IPA or an appropriate cleaner for the coating or substrate material to remove release agents, processing residues, and surface contamination.
- For powder-coated and painted surfaces, light abrasion of the bond area followed by a second IPA wipe is recommended to improve adhesion to the coating surface.
- For composites and plastics, confirm the solvent used for cleaning is compatible with the material. Abrasion followed by re-cleaning is recommended for most composite substrates.
- Bond immediately after surface preparation to prevent re-contamination before adhesive application.
Note: The level of surface preparation required depends on the target bond strength and the environmental aging resistance needed for the application. Refer to the 3M™ Scotch-Weld™ DP490 Technical Data Sheet for substrate-specific preparation procedures and environmental test data. Always verify bond performance on representative samples before finalizing assembly parameters.
Safe Use and Storage
DP490 is a two-component reactive epoxy adhesive. Refer to the Safety Data Sheet (SDS) for complete hazard information, personal protective equipment requirements, and disposal guidance before handling either component.
Safe Handling
- Wear chemical-resistant gloves (nitrile or equivalent) and eye protection when handling either component or the mixed adhesive. Epoxy components can cause skin sensitization with repeated contact.
- Use in well-ventilated areas. Avoid prolonged inhalation of vapors from either component, particularly the hardener (Part B).
- Do not use solvents to clean adhesive from skin. In the event of skin contact, wash immediately with soap and water.
- For eye contact, flush with clean water for at least 15 minutes and seek medical attention promptly.
- For industrial and occupational use only. Not for consumer sale or use.
Storage Conditions
- Store DP490 in original sealed containers at temperatures between 60°F and 80°F (16°C and 27°C). Avoid storage above 90°F (32°C), which can accelerate component degradation and reduce shelf life.
- Do not freeze. Freezing may permanently alter the viscosity and mixing characteristics of either component.
- Shelf life is typically 12 months from date of manufacture when stored in original sealed containers at recommended temperatures. Check the product label for the specific expiry date before use.
- Store away from heat sources, open flames, and incompatible materials. Refer to the SDS for specific storage incompatibilities.
- Dispose of unused material and empty containers in accordance with applicable local and national regulations for epoxy adhesive waste.
Best Practices for Consistent Bond Performance
- Allow adhesive cartridges to equilibrate to room temperature before use if stored in a cool location. Cold adhesive has higher viscosity and may not dispense evenly, affecting mix ratio consistency and bead uniformity.
- Always dispense a short purge bead onto a waste surface before applying to the workpiece to confirm both components are flowing and the mixing nozzle is delivering properly blended material.
- Do not exceed the 90-minute work life. Once the adhesive begins to gel, repositioning the substrates will disrupt the developing bond and compromise joint integrity. Remove and reapply fresh adhesive if the work life has been exceeded.
- Apply consistent contact pressure and maintain fixturing throughout the cure period. Minimum bond strength (approximately 1,000 psi overlap shear) is typically reached in 4 to 6 hours; do not disturb the joint before this threshold is reached.
- For applications where in-process mix ratio accuracy needs to be verified, consider pairing DP490 Duo-Pak cartridges with the 3M™ Adhesive Mix Monitor for real-time in-line mix quality monitoring.