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G/flex 650 Toughened Epoxy

G/flex® 650 is a toughened, versatile, liquid epoxy for permanent waterproof bonding of fiberglass, ceramics, metals, plastics, and damp and difficult-to-bond woods. It is a bit more flexible than standard epoxies and polyester but much stiffer than adhesive sealants. This gives it the ability to make structural bonds that can absorb the stress of expansion, contraction, shock, and vibration. It is ideal for bonding dissimilar materials. It can be modified with WEST SYSTEM® fillers and additives and used to wet out fiberglass tapes and fabrics. This system is simple to use with its 1:1 mix ratio by volume.

G/flex 650 Toughened Epoxy Adhesive is designed to bond to:

  • Plastics
  • Metals
  • Glass
  • Masonry
  • Fiberglass


WEST SYSTEM| image: 650-8-with-bottles


  • Aluminum Boat Repair
  • Polyethylene & ABS Canoe/Kayak Repairs
  • General Bonding
  • Wetting Out Fiberglass

Product Specifications:

  • Mix Ratio By Volume | 1:1
  • Pot Life | 46 Minutes
  • Working Time | 75 Minutes
  • Full Cure | 24 Hours @ 72°F
  • Modulus Elasticity | 150,000 PSI
  • Color | Amber
  • Consistency | Honey

Consumer Package Includes*:

  • 1x Resin
  • 1x Hardener

*Industrial Sizes C & E Resin and Hardener sold Separately


  • 650-8 | Two, 4 fluid oz
  • 650-32 | Two, 16 fluid oz
  • 650-2G | Two, 1 gal
  • 650-CR | Resin | 4.75 gal
  • 650-CH | Hardener | 4.75 gal

G/flex Features

Choosing Your Epoxy

Selecting the right epoxy system can feel overwhelming. This Epoxy System Selection Guide helps highlight the differences between the systems so you can pick which system will work best for your project.

Home Repairs

WEST SYSTEM Epoxy has been used to reliably build and repair boats for over thirty-five years. But its practical uses are not limited to boats or the marine industry. The techniques used to restore an aging runabout, repair a delaminated fiberglass deck or build a stripper canoe are the same techniques used to restore historic buildings, repair damaged vehicles, and build weatherproof outdoor furniture. If you’ve used epoxy on a boat repair or building project, it’s likely you’ve found other uses for it around your house or shop. We have put together a manual of some of the more common non-marine uses of epoxy.

Using WEST SYSTEMSpecialty Epoxies