Epoxy glue is one of the most versatile and heavy-duty adhesives available. Known for its incredible bonding strength and durability, epoxy can be used to join and repair a wide variety of materials. But with so many epoxy glue products on the market, how do you know which is the best choice for your specific project?
What is Epoxy Glue?
Epoxy glue is a two-part adhesive that consists of an epoxy resin and a polyamine hardener. When these two components are mixed together, a chemical reaction is triggered that causes the liquid or paste to harden into a rigid, durable bond.
Unlike other adhesives that dry through evaporation, epoxy glue actually cures. This curing process allows epoxy to form exceptionally strong bonds between materials. The cross-linked structure created by epoxy resin and hardener makes epoxy glues more resistant to temperature, chemicals, and moisture than many other adhesives.
Once cured, epoxy forms permanent bonds that can be stronger than the materials being adhered.
Characteristics of the Best Epoxy Glues
With an understanding of what epoxy glue is and its many benefits, you can now focus on the specific characteristics that make up the highest quality epoxy adhesives. The best epoxy glue for your project will excel in these areas:
Strong Bond Strength
This is the number one criteria for any adhesive, and epoxy is valued for its exceptionally high bond strength of up to 3,700 PSI. Industrial grade epoxy can have even greater bonding power, measured in the thousands of PSI. The strongest epoxy glues will form permanent bonds stronger than the substrates being adhered.
Gap Filling Properties
Look for an epoxy that easily flows into cracks and gaps without sagging or running. The best epoxy glues can bridge gaps up to 1/4 inch wide, bonding uneven or poorly fitting surfaces securely.
Chemical and Water Resistance
To maintain their powerful bond strength, epoxy glues need excellent resistance to solvents, chemicals like acids or bases, and moisture. Opt for epoxy adhesives made for wet, humid, or chemically demanding applications.
Versatile Bonding
Make sure the epoxy you choose can adhere to the substrates you need to bond. The most versatile epoxy glues work on metals, plastics, glass, wood, concrete, fiberglass, ceramics, and more.
Adequate Cure Time
Cure time can range from a few minutes to hours or even days, depending on the epoxy glue. Make sure to match the cure time to your project needs. Quick setting epoxy is good for small repairs while slow cure epoxy allows more working time for large projects.
Non-Toxic and Low Odor
Many epoxy glues contain noxious fumes during curing that can irritate eyes and airways. Look for low odor, non-toxic epoxies when working in enclosed spaces.
Types of Epoxy Glue
There are several specialized formulations of epoxy glue available for different applications:
Two-Part Epoxy
This is the most common type, with separate resin and hardener components that must be mixed before use. It provides the strongest and most rigid bonds. Two-part epoxy is sold in tubes, syringes, or bottles.
One-Part Epoxy
A resin and hardener pre-mixed into one component. Just dispense and apply. One-part epoxy cures more slowly but is easier to apply. It’s not quite as strong as two-part.
Cold Weld Epoxy
This high strength formula is meant for metal bonding and dries quickly at room temperature. Cold weld epoxy doesn’t require heating metal surfaces before application.
Underwater Epoxy
Formulated to cure even in wet conditions, underwater epoxy glue is commonly used in marine repairs. It provides a watertight seal and strong bond.
Clear Epoxy
Clear epoxy adhesives are designed for invisible repairs of transparent items like glass. They dry crystal clear for an invisible bond line.
Quick-Setting Epoxy
These fast-curing epoxies set in just minutes, allowing for quick repairs and bonding. However, bond strength is lower than slower-curing epoxy glue.
Flexible Epoxy
Flexible epoxies contain additives like rubber that allow for more elasticity in the bond. Useful when bonding materials with differential expansion.
Top Epoxy Glue Brands
With a dizzying array of epoxy adhesives on the market, sticking to brand names known for quality can help narrow your choices. Some of the leading epoxy glue manufacturers include:
Best Overall: J-B Weld 2-Part Epoxy
Key Features:
- Strong dual-syringe packaging for mess-free mixing
- Cures in 4-6 hours with full strength in 24 hours
- Withstands temperatures up to 550°F
J-B Weld’s 2-Part Epoxy is my top choice for its convenience, strength, and versatility. The dual-syringe design ensures mistake-proof mixing and dispensing every time. This epoxy cures to an extremely rigid bond that withstands heavy impacts, vibration, chemicals, and high temperatures up to 550°F. It bonds to wood, metal, glass, fiberglass, ceramics, masonry, and many plastics. With off-the-charts adhesion and shear strength, J-B Weld Epoxy takes on the toughest projects while still offering flexibility and ease of use.
Best for Metal: Loctite Epoxy Metal / Concrete
Key Features:
- Designed specifically for metal repairs
- Withstands vibration, shock, and heavy loads
- Water and chemical resistant
Loctite’s Epoxy Metal / Concrete is engineered for the demands of metal bonding. This heavy-duty epoxy cures into an exceptionally rigid bond able to withstand constant vibration, shock, and heavy loads in harsh environments – making it ideal for structural metal repairs. It also offers superior adhesion to concrete. The putty-like consistency excels at filling gaps and surface imperfections. For rock-solid metal repairs that last, Loctite Epoxy is the go-to choice.
Best for Plastic: J-B Weld PlasticWeld
Key Features:
- Specifically formulated for plastic repairs
- Cures quickly with no clamping required
- Withstands impacts, chemicals, and vibration
As the name implies, J-B Weld’s PlasticWeld Epoxy is engineered specifically for plastic repairs. The formula creates flexible, impact-resistant bonds on plastics like ABS, PVC, fiberglass, plexiglass, and polycarbonates. It cures in 4-6 hours into a rigid structure able to withstand chemicals, vibration, and impact damage. The no-clamp formula also saves time and hassle. For durable plastic repairs, J-B Weld PlasticWeld is the top choice.
Best Quick-Set: Gorilla 2-Part 5 Minute Epoxy Gel
Key Features:
- Sets completely in just 5 minutes
- Gel formula for drip-free application
- Bonds to wood, metal, glass, ceramic, and more
When you need a fast-acting epoxy, Gorilla 2-Part Epoxy Gel is the answer. This quick-bonding epoxy achieves full strength in just 5 minutes. The no-drip gel formula makes application easy for vertical and overhead surfaces. It bonds to wood, metal, glass, ceramic, rubber, and many plastics – making it ideal for quick fixes and impromptu projects. The fast cure time also allows for repositioning of surfaces during the first minute of application.
Best for Wood: PC Woody 2-Part Epoxy Paste
Key Features:
- Formulated specifically for wood materials
- Fills cracks and gaps in wood
- Stains and paints easily after curing
PC Woody offers an epoxy engineered specifically for wood repairs and projects. This paste-like formula is easy to sand, stain, and paint after full curing. It expands and contracts at the same rate as wood for durability. The epoxy fully cures in 6-8 hours into an incredibly strong, rigid bond that fills cracks and gaps in damaged wood. For flawless wood repairs, PC Woody is the top choice.
Best Clear-Drying: Pratley Clear 2-Part Epoxy
Key Features:
- Crystal-clear optical clarity
- Bonds glass, ceramic, metal, wood, and more
- Withstands extreme impact and vibrations
Pratley Clear Epoxy offers the strength of traditional epoxy in a crystal-clear formula. It dries optically transparent for an invisible bond line. The water-resistant adhesive excels at bonding glass, ceramic, metal, wood, fiberglass, and plastics with a durable hold. This epoxy withstands extreme impacts, shocks, vibration, and abusive environments. For a subtle yet mighty bond, Pratley Clear is the go-to choice.
Best Large Volume: PC Products PC-7 2-Part Epoxy Paste
Key Features:
- Available in large 2-gallon kits
- Gap-filling paste consistency
- Bonds to damp surfaces
For big bonding projects, choose the large-volume packaging of PC Products PC-7 Epoxy Paste. This high-strength epoxy comes in 2-gallon kits – 20 times more product than standard syringes. The putty-like consistency excels at filling gaps, bonding uneven surfaces, and forming structural repairs. It also adheres to damp surfaces. PC-7 cures in 16 hours into an extremely rigid, high-strength bond able to withstand harsh conditions. Order this epoxy by the gallon for major repairs and installations.
Best Underwater: Sea Hawk Aluminum Boat Epoxy
Key Features:
- Specifically formulated for underwater use
- Resistant to saltwater, chemicals, and corrosion
- Bonds fiberglass, wood, metal, and composites
Sea Hawk Aluminum Boat Epoxy offers maximum water resistance and corrosion protection for underwater applications. This unique formula cures into a rigid structure that bonds tenaciously to fiberglass, wood, metal, and composite boat parts. It maintains bonding strength even after prolonged saltwater submersion. The epoxy resists chemicals, impacts, and abrasion. For durable repairs in wet marine environments, Sea Hawk Epoxy is the top choice.
Epoxy Glue vs. Other Adhesives
Epoxy glue stands apart from other adhesives thanks to its unmatched bonding versatility, strength, and durability. Here’s how it compares:
Vs. Super Glue
- Epoxy bonds a wider variety of materials than super glue. It also offers substantially higher strength and shock resistance.
- Super glue sets and cures faster. Epoxy allows more time for positioning parts.
- Super glue is more suitable for small-scale repairs on limited surfaces. Epoxy handles larger projects and uneven materials.
Vs. Construction Adhesives
- Epoxy offers superior strength and longevity compared to construction adhesives. It also handles harsh environmental conditions better.
- Construction adhesives are easier to apply in large volumes and wet conditions. Epoxy requires precise mixing and dry surfaces.
- Construction adhesives bond common porous building materials like wood and drywall. Epoxy excels at metals, glass, concrete, and more.
Vs. Hot Glue
- Epoxy creates a much stronger, more rigid bond than hot glue. It also withstands much higher temperatures.
- Hot glue sets almost instantly, while epoxy requires longer cure time. Hot glue also requires heat for application.
- Due to fast drying, hot glue is better for quick, temporary bonds. Epoxy is superior for lasting repairs and projects.
Thanks to its unparalleled versatility and bonding strength, epoxy is the clear winner over other common adhesives for demanding repairs and industrial applications.
Choosing the Best Epoxy Glue
With so many options on the market, choosing the right epoxy glue for your particular repair or project may seem daunting. Follow this decision process:
Step 1: Identify the Materials You Are Bonding
Epoxy can bond just about any materials, but some epoxies are formulated specifically for certain substrates. Identifying the materials to be bonded will help narrow adhesive choices.
Step 2: Determine Required Bond Strength
Consider the stresses and forces the epoxy repair or bond will need to withstand. Structural repairs demand the highest strength epoxy. For light duty craft bonds, standard hardware epoxy will suffice.
Step 3: Calculate the Size of Gaps or Cracks
Measure the gaps or damaged areas you need to fill with epoxy. Look for an epoxy glue rated to bridge larger gaps, like 1/4 inch or more, for best results.
Step 4: Decide on Cure Time Needed
Quick-setting epoxies gain handling strength in minutes but take days to fully cure. Slow-curing epoxies take hours to set but deliver the strongest bond. Choose cure time suitable for your project scale.
Step 5: Evaluate Environmental Factors
Consider whether the epoxy repair will be exposed to water, chemicals, or temperature extremes. Select epoxy adhesives formulated for waterproof, chemical resistant bonds if needed.
Step 6: Review Health and Safety Precautions
Read product safety warnings carefully, especially for industrial grade epoxies. Opt for low fume or odorless epoxy when working indoors or in enclosed areas.
Best Epoxy Glue Options
Here are some top-rated epoxy glues to consider for various common applications:
Best Epoxy for Metal – J-B Weld Steel Reinforced Epoxy
J-B Weld has specially formulated this 2-part cold weld epoxy paste to provide exceptional strength for metal repairs up to 3,930 PSI. The included steel powder gives added durability. It bonds steel, aluminum, iron, and more.
Best Epoxy for Wood – Gorilla 2 Part Epoxy Syringe
Gorilla’s epoxy adhesive flows easily into cracks and voids in wood and cures in just 25 minutes with full strength in 1-2 hours. It won’t sag or drip and is water and solvent resistant.
Best Epoxy for Plastic – Loctite Epoxy Plastic Bonder
This Loctite product chemically fuses plastics like PVC, ABS, fiberglass, and polycarbonate into a permanent, waterproof bond. The putty consistency is great for quick repairs.
Best Epoxy for Concrete – PC Products PC-Concrete Epoxy Paste
Formulated to repair cracks, holes, and defects in concrete and masonry, this paste epoxy has a long 90 minute working time for large jobs. It bonds to damp surfaces.
Best Clear Epoxy – Gorilla 2 Part Clear Epoxy
Gorilla’s crystal clear epoxy adhesive is ideal for see-through repairs on glass, plastic, and ceramic items. It dries transparent with a rigid, durable bond and water/chemical resistance.
Best Fast Cure Epoxy – J-B Weld Quick Setting Epoxy Syringe
This fast-acting epoxy from J-B Weld sets hard in just 4-6 minutes. It allows for quick repairs but has lower strength than standard cure epoxies. Useful for small repairs.
Best Flexible Epoxy – Loctite Flexible Epoxy Adhesive
Loctite’s flexible epoxy formula bonds items subject to vibration, expansion, shock and movement. It remains flexible when cured for more elastic bonds than standard epoxy.
Best Underwater Epoxy – Marine Epoxy by Protective Coating Company
Specially formulated for wet conditions, this underwater epoxy glue makes permanent waterproof repairs on surfaces like fiberglass, metal, wood, and concrete.
Epoxy Glue Tips and Tricks
Follow these tips when working with epoxy glue for best results:
- Carefully follow all mixing and application instructions. Improper use can severely reduce bond strength.
- Thoroughly clean and roughen surfaces before application so the epoxy can form a tight mechanical bond.
- Clamp glued items with constant, even pressure as the epoxy cures for a stronger bond.
- Allow the full recommended curing time before subjecting epoxy bonds to any stresses or forces.
- Wear gloves when mixing and applying epoxy, as continuous skin contact can cause irritation for some people.
- Store epoxy adhesives at room temperature, away from extreme cold or heat to prevent altering the chemical properties.
- Apply epoxy in thin layers – thick globs take longer to cure fully and shrink more.
- If repositioning bonded items before curing, slide pieces rather than pulling them apart to avoid damaging the epoxy bond.
The Many Uses of Epoxy Glue
Thanks to its versatility, epoxy glue can be used in countless applications including:
- Permanently bonding metal parts in machinery and equipment
- Assembling fiberglass molds, tools, and panels
- Installing metal anchors and rods in concrete and masonry
- Gluing sections of wood to create furniture, crafts, and decor
- Repairing cracks and flaws in ceramic, pottery, and porcelain items
- Adhering plastic components in manufacturing or repairs
- Securing glass in frames, displays, and broken windows
- Fixing leaks in plumbing and piping
- Creating jewelry using gemstones and metals
- Waterproofing electrical connections
Conclusion
Epoxy glue’s unrivaled versatility, strength, and durability make it the go-to for both household and industrial bonding challenges. It outperforms other adhesives to create professional-grade repairs and assemblies able to withstand extreme environmental conditions. Just be sure to match the formula to your materials and project requirements.