655-1 G/flex Syringe

655-1 G/flex Epoxy Syringe
655-1 G/flex Epoxy Syringe

Versatile G/flex Thickened Epoxy Adhesive is now available in a convenient dispensing syringe.

  • Great on plastics including HDPE, LDPE, ABS, PVC, Polycarbonate, and Hypalon.
  • Easy-to-use syringe to dispense small quantities of epoxy
  • Viscosity similar to gel toothpaste—won’t run or sag

G/flex 655 is a toughened epoxy that makes permanent, waterproof structural bonds. It absorbs the stresses of expansion, contraction, shock, and vibration. G/flex adheres tenaciously to HDPE, LDPE ABS, PVC, Polycarbonate, and Hypalon plastics. It also bonds metal, glass, masonry, fiberglass, and wood. The G/flex 655-1 syringe contains 0.42 oz of resin and 0.42 oz of hardener, perfect for small repair jobs.


uses plastics (HDPE, LDPE, ABS,
PVC, Polycarbonate, Hypalon)
metals, glass, masonry, fiberglass, and woods
working time 45 min.
gel time 3-4 hours
cure time 7-10 hours
full cure 24 hours
min. temp. 40°F (4°C)

NOTE: Cure times are based on 72°F (22°C) ambient temperature. Cure times are faster at higher temperatures and in thicker applications.


G/flex Epoxy Adhesion Data & Surface Prep

G-flex Technical Data (pdf)

G/flex 655 Resin Safety Data (pdf)

G/flex 655 Hardener Safety Data (pdf)

Toughness and flexibility of G/flex Thickened Epoxy

G/flex has been toughened so it’s resilient and impact resistant. With a modulus of elasticity of 150,000 psi (WEST SYSTEM 105 Resin/205 Hardener has a modulus of elasticity of 450,000 psi), G/flex is more flexible and can deflect further before breaking than WEST SYSTEM 105/205, while being much stiffer than typical adhesive sealants.

Adhesion to wet and damp surfaces

G/flex has the ability to glue damp woods. It can be used on wet surfaces, even underwater when applied with specific techniques.

Excellent adhesion to hard-to-bond woods

G/flex adheres tenaciously to difficult- to-glue hardwoods, both tropical and domestic varieties. This is important since many of the exotic and tropical species that are now being used to replace traditional woods present bonding challenges.

Bonds well to a variety of materials

G/flex® is ideal for bonding a variety of materials, including dissimilar ones. G/flex has a superior grip so that it can be used to bond to metals, plastics, glass, masonry, and fiberglass. G/flex is ideal for repairs to aluminum boats and polyethylene and ABS canoes and kayaks. It can also be used to wet out and bond fiberglass tapes and fabrics.

Ease of use

G/flex is a simple two-part epoxy system, and the 655-1 G/flex syringe makes it even easier to use. The syringe dispenses resin and hardener at the proper 1-to-1 mix ratio. G/flex provides a relatively long open working time, yet it cures quickly and can be used in cool temperatures. Because it is simple to mix and use, G/flex is an excellent starting point for customers new to epoxy use.

The versatility of G/flex Thickened Epoxy

G/flex can be modified with WEST SYSTEM® fillers and additives if you need to meet particular bonding needs. Adding G/flex to other WEST SYSTEM epoxies can improve their toughness and flexibility.

Adhesion Testing and Comparison of G/flex 650 (unthickened) and 655 Thickened Epoxy

How does G/flex adhere to woods and metals? Adhesion testing using the PATTI (Pneumatic Adhesion Tensile Test Instrument) on the same pieces of wood (with the wood sanded. Parallel to the grain with 80-grit sandpaper but no solvent wash) revealed that G/flex adheres to wood at least as well as any other WEST SYSTEM epoxy. With hardwoods and the often difficult-to glue species such as white oak, Ipe, teak, greenheart, purpleheart, and selangan batu, G/flex performed as much as 30% higher.

Adhesion testing with G/flex Epoxy on metals also yielded excellent results, typically exceeding the adhesion results achieved with 105 Resin-based epoxies.

Surface Prep/Conditions Tensile Adhesion (psi)
G-10 high-density laminate 650 80-grit sand / dry surface 3459
G-10 high-density laminate 655 80-grit sand / wet surface 2473
1018 steel 650 80-grit sand / dry surface 1772
1018 steel 655 80-grit sand / wet surface 3562
Galvanized steel 650 100-grit wet sand 2562
Galvanized steel 655 100-grit wet sand 2929
Copper 650 80-grit sand 2334
Copper 655 80-grit sand 2685
Bronze 650 80-grit sand 2782
Bronze 650 Scotch brite™ pad sand 2962
Bronze 655 80-grit sand 2936
HDPE plastic 655 Alcohol wipe, flame treat 1885
ABS plastic 655 80-grit sand 1535
Lexan™ 655 80-grit sand 1870
Ipe 650 60-grit sand 2134
Ipe 655 Plain isopropyl alcohol wipe x 3 2223
Teak, vertical grain 650 80-grit sand parallel to grain 1413
Teak, vertical grain 655 80-grit sand parallel to grain 1381
Teak, vertical grain 655 80-grit sand, alcohol wipe x 2 1503
White oak, vertical grain 650 80-grit sand 1935
White oak, vertical grain 655 80-grit sand 1780
White oak, vertical grain 655 Alcohol wipe x 2 2212
Purpleheart 650 60-grit sand parallel to grain 1731

G/flex 655 Thickened Epoxy Adhesive adheres to wet and damp surfaces well. However, gluing to wet surface is less than ideal. When bonding to a damp or wet surface,  the epoxy must be thick enough to displace the water to ensure a good bond. Pre-thickened G/flex 655 Adhesive can do this.

G/flex 655 comes in a wide variety of sizes. 655-1 is the smallest.