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)

Joint Sealants Brochure - Spanish

pdf (749.31 Kb)

LEED Letter

pdf (71.66 Kb)

Sealant Performance Selection Guide

pdf (872.11 Kb)