3M 1838
Harmonization Code : 3214.10.00 | Putty and other mastics | Resin cements, caulking compounds and other mastics
Main features
- Controlled-Flow Structural Bonding
- One-Hour Positioning Window
- Rigid High-Shear Performance
Product Description
3M Scotch-Weld Epoxy Adhesive 1838 B/A Green is a green, two-part, room-temperature-curing structural epoxy with controlled flow for precise placement on metals, wood, and selected plastics. Part B and Part A mix at 4:5 by volume or 1:1 by weight, producing a uniform green material with a typical 60-minute open time and 60-minute work life for a 100 g mass at 23 deg C. The high-viscosity formulation limits movement after dispensing and cures to a rigid bond with high shear strength and environmental resistance. It is suited to structural assembly where accurate application, extended positioning time, and a firm cured bond are required.
Key features
- Controlled-flow placement: High component viscosity limits movement and supports precise dispensing on the bond area.
- Defined two-part ratios: Part B and Part A mix at 4:5 by volume or 1:1 by weight.
- Extended positioning time: Typical open time and 100 g mixed work life are each 60 minutes at the stated conditions.
Applications
Applications include structural bonding of metals, wood, and selected plastics where controlled flow, room-temperature cure, and extended positioning time are required.
TDS, SDS & Technical Documents
Technical Specifications
General Properties
Physical Properties
Mechanical Properties
Thermal Properties
Electrical Properties
Additional Information
As-supplied / before-processing properties
Component properties and mixed-material handling values remain separated; mix ratios retain their stated basis.
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Mix ratio by volume (B:A) | 4:5 | - | Before application |
| Mix ratio by weight (B:A) | 1:1 | - | Before application |
| Base resin | Modified epoxy | - | Part A |
| Accelerator resin | Polyamide | - | Part B |
| Base viscosity | 70,000 to 600,000 | cP | Part A at 27 deg C |
| Accelerator viscosity | 300,000 to 1,000,000 | cP | Part B at 27 deg C |
| Open time | 60 | min | Typical mixed material |
| Work life | 60 | min | 100 g mixed at 23 deg C |
Final-state / after-processing properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Cured color | Green | - | Typical |
| Modulus | 344,000 | psi | Typical at 23 deg C |
| Shore D hardness | 82 | - | ASTM D2240 at 23 deg C |
| T-peel adhesion | 4 | lb/in width | ASTM D1876; aluminum at 23 deg C |
| Elongation at break | 2 to 3 | % | Typical |
| Tensile strength at break | 4,290 | psi | Typical |
| Glass transition temperature | 55 | deg C | Midpoint; DSC second heat at 20 deg C/min |
| Volume resistivity | 1.5 x 10^15 | ohm-cm | ASTM D257 at 23 deg C |
