MGS LH 637 Epoxy Hardener - SLOW

MGS LH 637 is a slow-reactivity epoxy curing agent specifically formulated for use with MGS LR 635 epoxy resin. Designed for large composite structures and extended processing applications, LH 637 provides exceptionally long working times, making it the preferred hardener for large-scale resin infusion, complex laminations, and projects requiring maximum processing flexibility.

When combined with LR 635 resin, LH 637 allows fabricators to maintain low resin viscosity and extended pot life throughout the manufacturing process, ensuring complete fiber wet-out and thorough impregnation of fiberglass, carbon fiber, and aramid reinforcements. This extended processing window is particularly beneficial when manufacturing large wind turbine components, marine structures, tooling, and other high-performance composite parts.

Following proper cure and post-cure schedules, the LR 635 / LH 637 system delivers excellent mechanical properties, durability, and thermal stability for demanding structural applications.

Extended Working Time for Large Projects

One of the key advantages of LH 637 is its exceptionally long pot life, providing composite manufacturers with maximum control during complex layups and infusion processes. Under standardized laboratory conditions, LH 637 offers pot life exceeding 5 hours, making it ideal for large molds, thick laminates, and projects where extended processing time is critical.

The slower cure profile reduces the risk of premature gelation, allowing operators to achieve consistent laminate quality across large or intricate composite structures.

Customizable Cure Profiles

For even greater processing flexibility, LH 637 can be blended with faster-reacting hardeners such as LH 635 to create intermediate cure speeds and customized working times.

By adjusting the ratio of LH 635 and LH 637, manufacturers can tailor pot life, gel time, and cure schedules to meet specific production requirements. This unique flexibility allows fabricators to optimize processing windows for everything from small repairs and hand laminations to large-scale resin infusion projects while maintaining the proven performance of the MGS LR 635 system.

Features & Benefits

• Designed specifically for use with MGS LR 635 epoxy resin

• Extremely long working time for large-scale manufacturing

• Pot life exceeding 5 hours under standardized test conditions

• Ideal for resin infusion and vacuum-assisted processes

• Excellent fiber wet-out and laminate quality

• Compatible with fiberglass, carbon fiber, and aramid reinforcements

• Reduces risk of premature gelation during complex laminations

• Can be blended with LH 635 to create customized cure profiles

• Allows manufacturers to fine-tune processing windows and production schedules

• Excellent mechanical properties and durability after cure

• Suitable for large structural composite applications

• Proven performance in wind energy, marine, tooling, and industrial manufacturing

Typical Applications

• Wind turbine blade manufacturing and repair

• Large-scale resin infusion projects

• Marine hulls, decks, and structural components

• Composite tooling and molds

• Carbon fiber and fiberglass structures

• Industrial composite manufacturing

• Thick laminate construction

• Complex multi-stage laminations

Mixing Ratio

When used with MGS LR 635 resin:

• 100 parts LR 635 Resin

• 30 parts LH 637 Hardener by weight

Accurate mixing and thorough blending are essential to achieve optimal curing performance and final mechanical properties.

MGS LH 637 is the hardener of choice when maximum working time, processing flexibility, and dependable structural performance are required. Its extended pot life and ability to be blended with other MGS hardeners make it an invaluable solution for demanding composite manufacturing environments.