ARALDITE® AV 138 M-2: The high chemical and temperature resistant structural epoxy paste
Samaro presents ARALDITE® AV 138 M-2 / HV 998-1, a 2K thixotropic epoxy adhesive delivering high strength after cure, designed for demanding assemblies exposed to high temperatures and aggressive environments (chemicals, humidity). Ideal for bonding metals, ceramics, glass, rubber, rigid plastics, and other substrates.
AV 138 M-2: consistent performance, modernized HSE profile
AV 138 M-2 replaces AV 138 M-1 following the reclassification of a resin-side raw material. The goal: maintain AV 138 M-1’s handling and performance levels while updating the regulatory/HSE profile. Huntsman’s comparative tests show very similar characteristics between the two grades.
What’s changing between ARALDITE® AV 138 M-1 and AV 138 M-2
- Raw-material substitution on the resin side (AV 138 M-2); hardener HV 998-1 unchanged.
- Similar behavior in application and in service per the comparative report (thixotropic viscosity, mechanical strengths, aging).
- Slightly adjusted shop-floor window: working time ~75 min (10 g, 23 °C) for AV 138 M-2 (vs ~65 min for AV 138 M-1).
Key benefits
- Heat & chemical resistance: high performance at elevated temperatures and excellent chemical resistance after cure.
- Thixotropic, non-sag paste: gap filling with clean vertical application.
- Comfortable processing window: ~75 min (10 g, 23 °C) to position and dispense with ease.
- Multi-substrate capability: metals, ceramics, glass, rubber, and rigid plastics.
- Controlled transition from AV 138 M-1: aligned behavior, easier qualification.
| Specification sheet – ARALDITE® AV 138 M-2 / HV 998-1
Type : |
2-component epoxy adhesive, thixotropic paste |
| Appearance (mixed): | Dark grey paste. |
| Mix ratio (resin:hardener): | 100:40 by weight and by volume (≈ 1:0.4). |
| Working time (10 g, 23 °C): | ≈ 75 min. |
| Shear strength (23 °C, grit-blasted Al): | ≈ 15 MPa (order of magnitude). |
| Service temperature range : | ≈ –60 °C à +160 °C |
| Tg (Tan δ, cure 16 h / 40 °C) : | ≈ 69–70 °C. |
AV 138 M-2 in practice: what your operators will see
- Clean beads, no run-off, including vertical applications and medium/large gaps.
- Calm, controlled placement thanks to ~75 min working time (10 g): dispense neatly, clean squeeze-out, let strength build.
- Built for harsh conditions: hot and chemically aggressive environments where chemical resistance and thermal stability make the difference.
Application best practices
Surface preparation: degrease (IPA/acetone depending on substrate), apply controlled abrasion, remove dust, and degrease again.
Metering & mixing: keep 100:40 by weight/volume; mix to full homogeneity; purge the 2K cartridge before dispensing.
Dispensing: lay continuous beads with steady pressure; avoid entrapped air.
Curing: follow your shop-floor cycle; allow progressive strength build at room temperature and, if needed, use a moderate cure (e.g., 16 h / 40 °C) per the TDS/comparison report.
Durability & testing
- Shear strength vs. temperature (ISO 4587): AV 138 M-1 and AV 138 M-2 show very similar profiles from –60 °C to +140 °C after 16 h / 40 °C.
- Chemical (90 days) & humidity aging (cataplasma ISO 9142 E2): comparable behavior.
- Tensile (ISO 527, 16 h / 40 °C): modulus ≈ 4.8 GPa, UTS ≈ 43 MPa, elongation at break ≈ 1.1% (AV 138 M-2).
Industries & use cases
- Equipment & process: assemblies exposed to solvents, oils, and chemical agents.
- Energy / transportation: parts located near heat sources or subject to thermal cycling.
- Instrumentation / technical glassware / ceramics: bonding of glass, ceramics, and metals where stiffness and high-temperature performance are required.
❓FAQ – ARALDITE® AV 138 M-2
🔹 Does the ratio change compared with AV 138 M-1?
No. It remains 100:40 by weight and by volume (resin:hardener) with HV 998-1.
🔹 What is the working time?
About 75 minutes (10 g, 23 °C) for AV 138 M-2 (per the comparative report).
🔹 Which substrates can be bonded?
Metals, ceramics, glass, rubber, rigid plastics, and other industrial materials.
🔹 What service temperatures does it cover?
Typical applications from –60 °C to +160 °C. Adjust according to your part/process constraints.
🔹 Can AV 138 M-1 be replaced by AV 138 M-2 without changing the process?
Huntsman’s report indicates similar characteristics; replacement may be possible without changing process conditions or part design validate against your internal standards.
