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407 Low-Density

Fairing Filler

407 Low-Density is a blended microballoon-based fairing filler for WEST SYSTEM® Epoxy. Add 407 to a mixture of epoxy resin/hardener to create a fairing putty. It’s easy to sand or carve this putty once it has cured. The filler is reasonably strong on a strength-to-weight basis. Blended with epoxy to a “peanut butter” consistency, it will be easy to fair. The higher the percentage of 407 in your epoxy mix, the easier it will be to fair. You can blend it into any WEST SYSTEM 105 Epoxy Resin®/200 Series Hardener combination.

Designed for :

  • Fairing
  • Carving
  • Thickening
WEST SYSTEM| image: 407-filler-group-copy


Thicken blended resin/hardener and create a multi-purpose adhesive for:

  • Large Scale Fairing
  • Fiberglass Repairs
  • Architectural Repairs
  • Autobody Repairs
  • Marine Repairs

Product Specifications:

  • Blended Microballoon base
  • Color | Red/Brown
  • Cures to Dark Red/Brown


  • 407-5 | 4 oz
  • 407-15 | 12 oz
  • 407-B | 14 lb

407 Low-Density Facts


Modifying with fillers and additives makes WEST SYSTEM epoxy extremely versatile for a wide variety of bonding and coating applications. Epoxy can be thickened to the ideal consistency needed for a particular job. Epoxy thickened with adhesive (high-density) fillers strengthens structural bonds, bridges gaps, and fills voids. Epoxy thickened with fairing (low-density) fillers is easily sanded and shaped after it cures.

Final Fairing

Final fairing is the last step in the fairing process. Its purpose is to correct any unevenness or flaws in the surface after the structure is completed. Final fairing begins with overall fairing, that is removing major high spots and/or filling low spots over broad areas. Then local fairing removes any remaining minor surface irregularities and makes the surface texture smooth to the touch.

Using WEST SYSTEMFillers & Additives