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- DOWSIL™ EA-3838 Fast Adhesive (Base & Catalyst)
DOWSIL™ EA-3838 Fast Adhesive (Base & Catalyst)
Harmonization Code : 3910.00.00.90 | Silicones in Primary Forms; Others
Main features
- Non-sag rheology
- Extreme temperature stability
- Flexible mix ratio
Product Description
DOWSIL™ EA-3838 Fast Adhesive is a two-part, fast room temperature curing thixotropic adhesive designed to provide durable bonding and sealing. It features a non-corrosive, neutral alkoxy cure with a non-self-leveling paste consistency. With excellent temperature stability ranging from -50°C to 180°C, it is ideal for components exhibiting different thermal expansion rates and applications requiring fast homogeneous cure and early adhesion development.
Product Key Features
- Fast Room-Temperature Cure - allows for rapid handling of bonded components and a fast assembly process with snap times as low as 2 to 3 minutes.
- Flexible Mix Ratios - can be dispensed at either a 2:1 or 4:1 base-to-catalyst volume ratio to suit specific production setups.
- Non-Sag Rheology - maintains a non-self-leveling, non-slump paste consistency for controlled application on various surfaces.
- Extreme Temperature Stability - maintains performance across a broad temperature range from -50°C to 180°C.
- Environmental Resistance - offers excellent weathering, U.V. resistance, and durable performance in hot and humid conditions.
Applications
This adhesive is suitable for a wide range of clean substrates, including plastics, metals, and glass, providing strong, flexible bonds without the need for primers in most cases.
- Appliance Manufacturing: Perfect for bonding glass to metal, painted metal, or plastic in ovens, refrigerators, and small home appliances.
- Automotive Assemblies: Suitable for automotive and automotive electronics assembly applications requiring a flexible, strong adhesive bond.
- Dissimilar Materials: Provides durable adhesive bonding and sealing for mixed-material components that exhibit different thermal expansion rates.
Technical Specifications
| General Properties | |||||
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Color
Color
The color |
Black | ||||
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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. |
1.34 | ||||
| Physical Properties | |||||
| Tack-Free Time | ratio 4:1/ ratio 2:1: 13 - 18/ 5-8 minutes | ||||
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Viscosity
Viscosity
Viscosity is a measurement of a fluid’s resistance to flow. Viscosity is commonly measured in centiPoise (cP). One cP is defined as the viscosity of water and all other viscosities are derived from this base. MPa is another common unit with a 1:1 conversion to cP. A product like honey would have a much higher viscosity -around 10,000 cPs- compared to water. As a result, honey would flow much slower out of a tipped glass than water would. The viscosity of a material can be decreased with an increase in temperature in order to better suit an application |
350,000 - 450,000 mPa.s | ||||
| snap cure | ratio 4:1/ ratio 2:1: 4-6/2-3 minutes | ||||
| Mechanical Properties | |||||
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Elongation
Elongation
Elongation is the process of lengthening something. It is a percentage that measures the initial, unstressed, length compared to the length of the material right before it breaks. It is commonly referred to as Ultimate Elongation or Tensile Elongation at break. |
>250 % | ||||
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Additional Information
Fast room temperature curing structural silicone
DOWSIL™ EA-3838 Fast Adhesive
DOWSIL™ EA-3838 Fast Adhesive is a two-part, fast room temperature curing thixotropic silicone adhesive. Engineered as a non-corrosive, neutral, alkoxy cure system, it delivers a fast and homogeneous cure in depth alongside rapid early adhesion development. Its non-self-leveling paste consistency allows for instant part handling, dramatically accelerating high-throughput assembly processes. It provides a strong, highly flexible bond designed to accommodate dissimilar thermal expansion rates across a diverse spectrum of substrates.
2:1 to 4:1 mix ratio by volume 2 to 6 min snap time Homogeneous depth cure Primerless adhesion
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Typical values only. Performance metrics and skin times vary based on the specific volume mix ratio utilized.
DOWSIL™ EA-3838 Fast Adhesive
Key Features
- Two-part thixotropic neutral silicone system provides an incredibly fast, deep, and uniform cure matrix.
- Non-slump paste rheology maintains precise bead geometry on vertical or overhead component joints.
- Primerless-to-surface adhesion develops rapidly across glass, various engineered plastics, and diverse metals.
- Outstanding weather, UV, and hot/humid resistance, surviving up to 7 days immersion in water at 70°C.
- Excellent thermal profile stability maintaining key rubber properties continuously from -50°C up to 180°C.
Processing Summary
Flexible Mixing Ratio: Designed to process smoothly at any custom mix ratio setting between 2:1 and 4:1 by volume. Weight parameters compute to 1.7:1 for a 2:1 volume mix, up to 3.4:1 for a 4:1 volume mix.
Snap & Tack-Free Times: At a 2:1 volume mix ratio, the snap time is 2-3 minutes with a tack-free window of 5-8 minutes. Adjusting to a 4:1 mix shifts snap time to 4-6 minutes and tack-free performance to 13-18 minutes.
Rapid Structural Handling: Reaches an early shear strength build-up of ≥0.5 MPa in just 15 minutes, jumping to 0.7 MPa by 60 minutes when evaluated at 2:1 volume settings.
Cure Acceleration: Achieves full engineering performance benchmarks after 7 days ambient resting at room temperature. Cure tracks and adhesion timelines can be further quickened with moderate heat application up to 60°C.
Handling and Application Guidance
Process Notes
Storage and Material Handling
- Usable shelf life tracks at 12 months from production date for both base and catalyst groups.
- Store unopened inside cool, dark spaces below 30°C.
- Extended hot storage exposure can slow down standard cure properties.
- Cure slowdown over time can typically be compensated by applying a higher catalyst mix ratio.
Surface Preparation
- Substrates must be clean, dry, and free of dust, extraneous matter, and oils.
- While primerless adhesion is typically excellent, custom adhesion targets can be boosted.
- Flame or plasma surface activation treatment options are compatible with optimization.
- Dow specialty chemical primers can also be utilized for high-bond target specs.
Equipment and Mixing
- Utilize meter/mix fluid machinery fitted with precision gear or piston pumps.
- Configure dispenses with an engineered static or dynamic mixing element assembly.
- Watch for marbled effects or light-colored streaks; they indicate inadequate product mix.
- Automated airless dispense machines are ideal to negate factory de-airing cycles.
Typical Properties
Engineering Data for DOWSIL™ EA-3838
Uncured Component Characteristics (As Supplied)
CTM: Corporate Test Method, copies of CTMs are available upon request. ASTM: American Society for Testing and Materials. DIN: Deutsche Industrie Norm.
| Property | EA-3838 Base (Black) | EA-3838 Catalyst | Test Standard |
|---|---|---|---|
| Appearance | Black viscous liquid | White paste | CTM 0176 B |
| Specific Gravity | 1.34 | 1.60 | ASTM D 0792 / CTM 0022 |
| Viscosity (1 s⁻¹) | 350 - 450 Pa·s | 550 - 700 Pa·s | DIN 5302 / CTM 1094 C |
| Viscosity (10 s⁻¹) | 150 - 200 Pa·s | 75 - 100 Pa·s | DIN 5302 / CTM 1094 C |
Cured Mechanical Properties (7 Days at 23°C, 2:1 by Volume)
| Mechanical Attribute | Typical Value | Test Method Standard |
|---|---|---|
| Durometer Hardness (Shore A) | 40 | ASTM D 2240 / CTM 0099 |
| Tensile Strength | > 1.5 MPa | ASTM D 412 / CTM 0137 A |
| Elongation at Break | > 250 % | ASTM D 412 / CTM 0137 A |
| Vertical Flow (Flow Resistance) | < 2 mm / 60 sec | As Mixed (Non-slump Paste) / CTM 0062 |
Adhesion Lap Shear Performance (7 Days at 23°C)
Lap shear metrics evaluated using a standard 2 mm structural adhesive bondline thickness under ASTM D 1002 / CTM 0243 protocols.
| Substrate Interface Combo | Lap Shear Strength Value | Cohesive Failure Rate (CF %) |
|---|---|---|
| Glass / Stainless Steel, Carbon Steel, Galvanized Steel | 1.4 MPa | 100% / 100% |
| Glass / Aluminum, Eloxal Coated Aluminum | 1.2 MPa | 100% / 100% |
| Glass / Polycarbonate (PC), Polyamide (PA) | 1.2 MPa | 100% / PC: 50%, PA: 100% |
| Glass / ABS, PBT | 1.0 MPa | 100% / 100% |
Applications
Where DOWSIL™ EA-3838 Fits
Automotive & Mobility
An elite solution for automotive electronics assembly operations that demand durable, highly flexible structural elastomeric joints.
- Optimized for structural display bonding.
- Bonds and seals electronic component housings.
- Serves as a reliable general maintenance sealant.
Consumer Appliances
A perfect bonding and sealing mechanism for home electronics, large white goods, and small home appliance production lines.
- Secures glass-to-metal and glass-to-painted metal.
- Bonds glass elements tightly onto plastic frames.
- Perfect for domestic ovens and refrigerators.
Industrial Infrastructure
Configured to survive industrial environments, handling components that exhibit vastly different linear thermal expansion rates.
- Reliable heavy-duty wind turbine component sealant.
- Performs general industrial sealing and gasketing.
- Absorbs structural movement without tearing.
Aerospace & Aviation
Engineered to pass aerospace and aviation assembly demands where fast homogeneous depth-cure is critical.
- High-strength sealing for aircraft cargo doors.
- Applies easily as a protective edge and gap sealant.
- Provides exceptional resistance to outdoor weather and UV.
Product Demo
See Two-Part Automated Meter-Mix Systems in Action
Observe the operation of automated piston-driven and gear-metered extrusion configurations for two-part thixotropic paste structural silicones. This industrial demo highlights critical automated monitoring practices, static/dynamic nozzle management, airless non-sag bead application profiles, and color uniformity quality tracking.
Package & Support
Standard Packaging & Technical Help
Standard Container Sizes
- Available in an array of standard protective container sizes.
- Detailed package and container metrics can be obtained from the closest Dow Sales Offices.
- Tightly sealed logistics safeguards components against premature ambient air activation.
Technical Help Capabilities
- Calibrating custom volumetric mixing ratios from 2:1 up to 4:1 settings.
- Analyzing custom component layouts to address varying thermal expansion differentials.
- Troubleshooting machine pump configurations to maintain continuous airless delivery.
- Guidance regarding regulatory safety and formal international product compliance tracking.
Technical Guidance
Tips and Troubleshooting
| Issue | Recommended Action |
|---|---|
| Light-colored streaks or marble patterning are visible in the bead profile |
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| A reduction or slowdown in the expected baseline cure processing speeds |
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| Boosting dính bám metrics on highly challenging substrate surfaces |
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Next Steps
Ready to Qualify DOWSIL™ EA-3838?
Share your performance, design, and manufacturing challenges. Tell us about your planned substrate materials, target line speeds, and dispensing equipment parameters. Our global support networks are ready to optimize the ideal mix ratio and mechanical application strategy for your plant floor.
