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|
|Bronze||650||Scotch brite™ pad sand||2962|
|HDPE plastic||655||Alcohol wipe, flame treat||1885|
|ABS plastic||655||80-grit sand||1535|
|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.