Plexus MA425 – Two-component methacrylate adhesive

PlexusTM MA425 is a two-part methacrylate adhesive designed for structural bonding of thermoplastic, metal, and composite assemblies.

Plexus MA425 – Two-component methacrylate adhesive

PlexusTM MA425 is a two-part methacrylate adhesive designed for structural bonding of thermoplastic, metal, and composite assemblies. Combined at a 10:1 ratio, it has a working time of 30 to 35 minutes and achieves 75% of ultimate strength in 80 to 90 minutes. Plexus MA425 is finding wide usage for composites bonding applications in the transportation and marine industries, because it requires virtually no surface preparation. In addition, this product provides a unique combination of excellent fatigue endurance, outstanding impact resistance, and superior toughness. Plexus MA425 is available in blue and is supplied in ready to use cartridges, 20 litre pails or 200 litre drums to be dispensed as a non- sagging gel.


Room Temperature Cure

  • Working Time
    • 30 – 35minutes
  • Fixture Time
    • 80 – 90 minutes
  • Operating Temperature
    • -55oC – 121oC
  • Gap Filling
    • 1mm to 10mm
  • Mixed Density
    • 0.96 g/cc
  • Flash Point
    • 9°C

Chemical Resistance

Excellent resistance to:

  • Hydrocarbons
  • Acids and Bases (3-10 pH)
  • Salt Solutions

Susceptible to:

  • Polar Solvents
  • Strong Acids and Bases

Recommended for

  • ABS
  • Acrylics
  • FRP
  • Gelcoats
  • PVC
  • Polyesters (including DCPD modified)
  • Styrenics
  • Urethanes (general)
  • Vinyl Esters

Handling and application

Plexus® MA425 adhesive (Part A) is flammable. Contents include Methacrylate Ester. Keep containers closed after use. Wear gloves and safety glasses to avoid skin and eye contact. Wash with soap and water after skin contact. In case of eye contact, flush with water for 15 minutes and get medical attention. Harmful if swallowed. Keep out of reach of children. Keep away from heat, sparks, and open flames. Reference the Material Safety Data Sheet for more complete safety information.

Note: Because of the rapid curing features of this product, large amounts of heat are generated when large masses of material are mixed at one time. The heat generated by the exotherm resulting from the mixing of large masses of adhesive can result in the release of entrapped air, steam, and volatile gases. To prevent this, use only enough material as needed for use within the working time for the product and confine gap thickness to no more than 10mm Questions relative to handling and applications should be directed to ITW Plexus at +44 (0)870 458 758

Dispensing adhesive

MA425 may be applied manually or with automated equipment. Static mixer selection is critical to the proper mixing and performance of Plexus adhesives. For additional information concerning meter-mix equipment, contact ITW Plexus Sales Representatives. Pre-measured cartridges are also available, as well as the hand-held guns with which to dispense the adhesive. To assure maximum bond strength, surfaces must be mated within the specified working time. Use sufficient material to ensure the joint is completely filled when parts are mated and clamped. All adhesive application, part positioning, and fixturing should occur before the working time of the mix has expired. After indicated working time, parts must remain undisturbed until the fixture time is reached. Automated equipment should be constructed of stainless steel or aluminum. Avoid contact with copper or copper containing alloys in all fittings, pumps, etc. Seals and gaskets should be made of Teflon, Teflon-coated PVC foam, ethylene/propylene or polyethylene. Avoid the use of Viton, BUNA-N, Neoprene or other elastomers for seals and gaskets. Clean up is easiest before the adhesive has cured. Citrus terpene or N-methyl pyrolidone (NMP) containing cleaners and degreasers can be used for best results. If the adhesive is already cured, careful scraping, followed by a solvent wipe may be the most effective method of clean up.

Effect of temperature

Application of adhesive at temperatures between 18oC and 26oC will ensure proper cure. Temperatures below 18oC will slow cure speed; above 26oC will increase cure speed. The viscosities of Parts A and B of this adhesive are affected by temperature. To ensure consistent dispensing in meter-mix equipment, adhesive and activator temperatures should be held reasonably constant throughout the year.

Storage and Shelf life

Shelf life of MA425 adhesive (Part A) is 1 year. Shelf life of activator (Part B), including cartridges that contain activators, is 9 months. Shelf life is based on continuous storage between 12oC and 23oC. Long term exposure above 23oC will reduce the shelf life of these materials. Prolonged exposure of activators, including cartridges that contain activators, above 37oC quickly diminishes the reactivity of the product and should be avoided. These products should never be frozen. For expiry date see label.


  1. ITW Plexus strongly recommends that all substrates be tested with the selected adhesive in the anticipated service conditions to determine suitability.
  2. Working Time: The time elapsed between the moment Parts A and B of the adhesive system are combined and thoroughly mixed and the time when the adhesive is no longer useable. Times presented were tested at 23oC.
  3. Fixture Time: The interval of time after which surface being joined will support a 1 kg dead weight on a 12.7 mm overlap joint 25.4 mm wide without movement. Times presented were tested at 23oC.
  4. Resistance to chemical exposure varies greatly based on several parameters including; temperature, concentration, bondline thickness, and duration of exposure. The chemical resistance guidelines listed assume long term exposures at ambient conditions.
  5. In a typical bond line, exotherm temperatures will be lower than the temperatures shown.
  6. Urethane-modified super- weathering gelcoats may require an alternate adhesive. As with all substrates, these gelcoats should be tested with the selected adhesive to determine suitability.
  7. For bond gaps below the minimum quoted please contact ITW Plexus.
  8. All machines dispensing Plexus should have shrouds where applicable.

All information on this data sheet is based on laboratory testing and is not intended for design purposes. ITW Plexus makes no representations or warranties of any kind concerning this data. Due to variance of storage, handling and application of these materials, ITW Plexus cannot accept liability for results obtained.


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