3M EC-3439
Harmonization Code : 3214.10.00 | Putty and other mastics | Resin cements, caulking compounds and other mastics

Main features
- Low Density Core Reinforcement
- Extended One Part Shop Life
- High Temperature Cured Performance
Product Description
3M Scotch-Weld Structural Adhesive EC-3439 HT is a beige, one-part modified epoxy void-filling compound for honeycomb-core reinforcement, edge finishing, insert bonding, and aircraft sandwich-panel work. Its cured density is below 0.75 g/cm3, and press-flow time is about 90 seconds at 26 deg C using the specified 4 bar, 2.6 mm orifice test. The material provides up to four days of shop life at 15 to 25 deg C and heat cures for one hour at 125 to 175 deg C. Cured compression and overlap-shear values cover subzero, room, and elevated test temperatures.
Key features
- Low Density Void Filling: The cured compound remains below 0.75 g/cm3 for lightweight core detailing.
- Four Day Shop Life: The one-part material can remain at 15 to 25 deg C for up to four days before processing.
- High Temperature Heat Cure: A one-hour cure window from 125 to 175 deg C supports controlled aerospace processing.
Applications
Honeycomb-core reinforcement, panel-edge finishing, insert bonding, local void filling, and aerospace sandwich-panel assembly.
Technical Specifications
No specifications available.
Additional Information
As-supplied / before-processing properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Chemistry | Modified epoxy | - | One-part compound |
| Color | Beige | - | As supplied |
| Press-flow time | Approximately 90 | sec | 20 g at 26 deg C; 4 bar; 2.6 mm orifice |
| Shop life | Up to 4 | days | Stored at 15 to 25 deg C before processing |
| Heat-cure time | 1 | h | At 125 to 175 deg C; heat-up rate 2 to 5 deg C/min |
After-processing / final-state properties
| Property | Value | Unit | Method / condition |
|---|---|---|---|
| Cured density | Less than 0.75 | g/cm3 | After cure |
| Compressive strength | 52.5 | MPa | Tested at 23 deg C after 125 deg C cure |
| Compressive strength | 65.4 | MPa | Tested at 23 deg C after 175 deg C cure |
| Compressive strength | 27.1 | MPa | Tested at 175 deg C after 125 deg C cure |
| Compressive strength | 38.1 | MPa | Tested at 175 deg C after 175 deg C cure |
| Overlap shear strength | 9.3 | MPa | Tested at -55 deg C after 175 deg C cure |
| Overlap shear strength | 8.8 | MPa | Tested at 23 deg C after 175 deg C cure |
| Overlap shear strength | 9.4 | MPa | Tested at 175 deg C after 175 deg C cure |





















