JH 1424 vs JH 1425: Choosing the Right Polyamide Hardener for Your Application
JH 1424 vs JH 1425: Choosing the Right Polyamide Hardener for Your Application
If you’ve ever worked with epoxy systems in coatings, adhesives, or marine environments, chances are you’ve encountered the two workhorses: JH 1424 and JH 1425.
At first glance, they look like siblings: both are solvent-free polyamide curing agents, both offer excellent adhesion and corrosion resistance, and both can be paired with standard liquid epoxy resins.
So, why do we even need two? The answer lies in how they behave during mixing and curing.
Meet the Two
🔹 JH 1424 – High viscosity, flexible performer
- Amine value: 210–240 mg KOH/g
- Viscosity: 45,000–60,000 mPa·s (at 40 °C)
- Pot life: Long
- Best for: Industrial paints, primers, adhesives, corrosion protection, marine coatings
- Signature trait: High flexibility + long pot life
🔹 JH 1425 – Medium viscosity, versatile hardener
- Amine value: 290–320 mg KOH/g
- Viscosity: 8,000–12,000 mPa·s (at 40 °C)
- Pot life: Balanced
- Best for: Adhesives, sealants, marine coatings, heavy-duty protective coatings
Signature trait: Tough bonding + corrosion resistance
Where They Shine
Imagine you’re formulating a ship deck coating. You need long working time, good flexibility to handle movement, and strong anti-corrosion properties.
👉JH 1424 is your ally. It holds up against tough marine conditions while allowing applicators the breathing space of a longer pot life.
Now consider a factory floor adhesive or sealant joint. You want strong adhesion, faster reactivity, and the ability to lock fillers into place without excess sagging.
👉 JH 1425 steps in. With higher amine value and lower viscosity, it balances workability with strength.
The Practical Dilemma
Both are proven. Both are reliable. But the selection depends on your workflow:
- Need longer open time, thicker body, or flexibility? → Choose JH 1424.
- Need quicker reactivity, lower viscosity, or tougher seals? → Go with JH 1425.
Quick Selector Snapshot
| Feature | JH-1424 | JH-1425 |
| Viscosity | Very high | Medium |
| Amine value | Lower (210–240) | Higher (290–320) |
| Pot life | Longer | Balanced |
| Flexibility | Higher | Moderate |
| Best use | Primers, marine, industrial coatings | Adhesives, sealants, heavy-duty coatings |
Pro Tip
Some formulators blend the two to fine-tune properties — using JH 1425 for adhesion strength and JH 1424 for flexibility and pot life extension. The result is a tailored system that performs across varying application demands.
Conclusion
Choosing between JH 1424 and JH 1425 isn’t about which is “better” — it’s about what your project needs.
- JH 1424 gives you time and flexibility.
- JH 1425 gives you strength and efficiency.
In the end, your resin system will thank you for picking the one that aligns with your application.
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