MasterSeal NP 125: One-component, elastomeric, gun-grade thermoplastic sealant and adhesive

Formerly: Sonolastic Clear 25

How does MasterSeal NP 125 work?

MasterSeal NP 125 is a one-component, high-performance, non-priming, gun-grade, thermoplastic adhesive and sealant. It requires no mixing and bonds tenaciously to common building materials, including concrete and clay roof tiles, metal flashings and masonry.

Recommended uses:

  • Residential
  • Commercial
  • Sheet roofing
  • Liquid applied roofs
  • Metal roofs
  • Shingled and tiled roofs
  • Between adjacent layers of roof tile
  • Sealing edge and ridge tiles
  • Penetration seals
  • Flashings
  • Skylight frames
  • Termination bars and reglets
  • Parapet expansion joints
  • Lap seals in metal roof assemblies
  • Sealing wood forms

What are the unique features of MasterSeal NP 125?

  • Superior holding power for longer lasting seals
  • Suitable for exterior applications (roofing)
  • Bonds similar and dissimilar materials
  • Clear formula blends with any substrate color
  • Wide temperature application range makes MasterSeal NP 125 suitable for all climates

What are the benefits of MasterSeal NP 125?

  • One-component formula requires no mixing, helping to reduce labor costs
  • Joint movement capability of 25% total provides excellent flexibility, keeping moving joints tightly sealed
  • Easy to gun and tool, speeding up application and making neater joints
  • Weather resistant for long-lasting weather tight seals
  • Compatible with non-rigid paints and can be painted

US / Canada Product Information

Data Guide

Data Guide (French)

Certification Letter

LEED Letter

Color Reference - MasterSeal NP 125

Direct contact

Master Builders Solutions Technical Support

Construction Systems


Safety Data Sheet (SDS)

Find all available safety data sheets for this product.



Product Certifications

Generate a free certificate of conformance for a specific BASF construction product.

Related Literature

Certification Letter

pdf (55.25 Kb)

Color Reference

pdf (166.60 Kb)

Data Guide

pdf (105.27 Kb)

Data Guide (French)

pdf (137.88 Kb)

LEED Letter

pdf (71.66 Kb)

Sealant Performance Selection Guide

pdf (872.11 Kb)