Adhesive type
Two-part epoxy
The general purpose structural adhesive: two components mixed to order, strong on almost everything, and genuinely good at filling gaps.
Also sold as Epoxy resin, 2K epoxy, rapid epoxy.
Two-part epoxy keeps an epoxy resin and a reactive hardener apart until you use them. Measure the stated ratio and mix right through the cup, including the sides and bottom. Too much hardener does not make it cure faster. It leaves material that cannot form the intended network, so the joint may stay soft or weak. Once mixed, curing is a chemical reaction throughout the bond line. It does not need air and does not rely on solvent escaping. A filled joint can therefore cure in depth, although a large mixed mass heats itself and may set much faster than the same mixture spread thin.
You can buy runny grades for wetting fibres and close joints, and pastes for larger gaps. Cured properties also vary. Ordinary grades are hard and rigid, while toughened grades tolerate more peel and impact. Working time ranges from minutes to hours, and heat can shorten it sharply. Epoxy usually bonds well to clean, abraded wood, metals, ceramics, concrete and many rigid composites. It is a poor blind choice for polyethylene, polypropylene, PTFE, silicone rubber or a flexible part that keeps bending. Water resistance can be good, but continuous immersion and food contact depend on the exact product. Sunlight chalks and degrades unprotected epoxy, so cover outdoor work with a suitable UV-resistant finish.
At a glance
- Strength
- Structural
- Flexibility
- Rigid
- Gap filling
- Medium
- Water resistance
- Water resistant
- UV resistance
- Poor
- How it cures
- Chemical reaction
- Typical working time
- 5 minutes to 2 hours
- Typical full cure
- 24 hours to 7 days
- Typical service temperature
- -40C to 100C
- Needs clamping
- Yes
- Two part
- Yes
These figures describe the family in general. Always use the numbers on the datasheet for the product you actually buy.
What it is for
Structural repairs in wood, metal and rigid composites; filling a controlled gap while bonding; laminating glass fibre or carbon fibre; rebuilding missing rigid material with a suitable filler; potting and encapsulating components; bonding ceramics, stone and concrete where the parts can be held still during cure.
Where it falls down
It is usually rigid and can crack or peel when a thin part flexes, vibrates or is struck. It does not reliably bond low-surface-energy plastics such as PE, PP or PTFE without specialist treatment. Wrong ratio or incomplete mixing produces uncured patches. A big batch can overheat and set before you place it. Standard epoxy yellows and degrades in sunlight. Cold conditions slow cure severely. Heat resistance, immersion resistance and bondability to damp surfaces vary too much to assume.
Getting a good bond
Remove paint, corrosion, wax, grease and release agent. Abrade sound material to expose a fresh, matt surface, then remove dust. Keep the surface dry unless the product expressly allows damp bonding. Degrease before abrasion when contamination could be driven into the surface. Measure both parts by the specified volume or weight ratio. Mix until completely uniform, scraping the sides and bottom. Wet both surfaces before adding a thickened mix to porous material. Hold the joint in position without squeezing out all the adhesive.
Safety
Read the SDS for both resin and hardener because the hazards are not interchangeable. Epoxy resins commonly irritate skin and can cause allergic skin sensitisation. Amine hardeners may be corrosive and can cause severe skin burns and serious eye damage. A representative EU hardener SDS also lists harmful skin contact and suspected reproductive toxicity. Avoid skin contamination, including repeated small smears. Do not use a dust mask as protection against vapour. Sand cured material with dust extraction. Mixed epoxy can become very hot in a cup, so do not leave a large mass to cure near combustible material.
Materials it suits
| Material | Suitability | Notes |
|---|---|---|
| Aluminium | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Brass | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Cast iron | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Concrete | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Copper | Excellent | Permabond states that two-component epoxies bond copper well. They suit larger loaded areas and provide more gap tolerance than an instant adhesive. Remove oil and oxide before bonding. Abrade first |
| Glass | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. A named primer, LSE formulation or controlled surface treatment may be essential. Suitability still depends on the other substrate, joint design and service environment. Primer needed |
| Glazed ceramic | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| GRP / fibreglass | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Mild steel | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Natural stone | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Porcelain | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Resin 3D print | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Stainless steel | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Unglazed ceramic | Excellent | Two-part epoxy is rated excellent for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| ABS | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| Acrylic | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| Anodised aluminium | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| ASA | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Chrome plated metal | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Galvanised steel | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| HIPS | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| Laminate | Good | 3M's structural-adhesive preparation guide says thermoset laminates can usually be bonded after removal of soil and release agent, with abrasion recommended for glossy surfaces. Use epoxy for local structural bonds, not as an unqualified substitute for a laminate contact process. Abrade first |
| Oak | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| PETG | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Pine | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| PLA | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| PLA+ | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Plywood | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Polycarbonate | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. Suitability still depends on the other substrate, joint design and service environment. |
| Teak | Good | Two-part epoxy is rated good for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Suitability still depends on the other substrate, joint design and service environment. Abrade first |
| Cork | Conditional | Epoxy can wet a clean cork surface and fill irregularities, but low-viscosity resin may soak in and a thick rigid bond line can concentrate stress in the weak cellular material. Use a thin controlled coat and light, even pressure after a test. |
| Melamine faced board | Conditional | Epoxy can form a local bond to a clean, keyed melamine face, but performance depends on the particular surface texture and finish. Abrade only the hidden bond area, clean it and test an offcut before relying on the joint. Abrade first |
| Painted metal | Conditional | Two-part epoxy is rated conditional for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Use only after a product-specific test on the actual grade and joint. Abrade first |
| POM (Delrin) | Conditional | Two-part epoxy is rated conditional for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. A named primer, LSE formulation or controlled surface treatment may be essential. Use only after a product-specific test on the actual grade and joint. Primer needed Abrade first |
| Powder coated metal | Conditional | Two-part epoxy is rated conditional for this material as an application-level assessment, not as a blanket manufacturer claim. The prepared surface must be sound and consistently keyed where the finish permits. Use only after a product-specific test on the actual grade and joint. Abrade first |
| Varnished wood | Conditional | Epoxy can bond a sound, keyed coating, but the joint remains limited by the coating-to-wood bond. For structural work, remove the finish to bare timber. WEST SYSTEM calls for removal of loose old coating and 80-grit abrasion in its epoxy process. Abrade first |
| HDPE | Poor | Two-part epoxy is rated poor for this material as an application-level assessment, not as a blanket manufacturer claim. A named primer, LSE formulation or controlled surface treatment may be essential. Use only after a product-specific test on the actual grade and joint. Primer needed |
| LDPE | Poor | Two-part epoxy is rated poor for this material as an application-level assessment, not as a blanket manufacturer claim. A named primer, LSE formulation or controlled surface treatment may be essential. Use only after a product-specific test on the actual grade and joint. Primer needed |
| Silicone rubber | Poor | Two-part epoxy is rated poor for this material as an application-level assessment, not as a blanket manufacturer claim. A named primer, LSE formulation or controlled surface treatment may be essential. Use only after a product-specific test on the actual grade and joint. |
Products in this family
3M 3M Scotch-Weld DP100 Plus
Clear, flexible two-part epoxy for metals, ceramics, glass and dissimilar surfaces.
Huntsman Araldite 2011 A/B
Multipurpose toughened room-temperature epoxy for metals, glass, ceramics, rubber, rigid plastics and wood.
WEST SYSTEM WEST SYSTEM G/flex 655 Thickened Epoxy Adhesive
Toughened, pre-thickened two-part epoxy for resilient, waterproof bonding of dissimilar and difficult substrates.
Last reviewed 8 October 2026.