For wood to wood, use PVA. For mixed materials, metal, or anything that needs to fill a gap, use a slow-setting two-part epoxy. Super glue (CA) is best for small, tight-fitting parts, including most 3D prints. Polypropylene and polyethylene barely stick to anything without a special primer.
The first chart shows which common hobby adhesives bond which materials. The second compares working time, clamp time, full cure, gap filling, strength, heat and water resistance. Search for a material or glue, or filter by glue family. To mix the right amount of epoxy for a pour or a coating, use the Epoxy Resin Calculator; for threaded fasteners, see the threadlocker guide.
What Glue Bonds What?
| Adhesive | Wood | Metal | PLA | PETG | ABS / ASA | Acrylic | Glass / ceramic | Rubber | Leather / fabric | PP / PE | Notes |
|---|---|---|---|---|---|---|---|---|---|---|---|
| PVA wood glue | Good | No | No | No | No | No | No | No | OK | No | Wood to wood only. Needs at least one porous surface. |
| CA / super glue (thin) | OK | OK | Good | OK | Good | OK | OK | Good | OK | No | Tight joints only. PP/PE need a polyolefin primer first. Fumes can leave white bloom on clear plastic. |
| CA / super glue (gel) | OK | OK | Good | OK | Good | OK | OK | Good | OK | No | Fills slightly bigger gaps and does not run. Same primer rule for PP/PE. |
| Epoxy, 5-minute | Good | Good | Good | OK | Good | OK | Good | Poor | OK | No | Quick repairs and small parts. Scuff plastics and metal first. |
| Epoxy, slow-setting (30 min+) | Good | Good | Good | OK | Good | OK | Good | Poor | OK | No | Strongest all-rounder: structural joints, metal, gap filling, outdoor. |
| Polyurethane (expanding) glue | Good | OK | OK | Poor | OK | Poor | OK | Poor | OK | No | Waterproof; foams to fill gaps, but the foam itself is weak. Needs moisture to cure. |
| Contact adhesive | Good | OK | OK | Poor | OK | No | Poor | Good | Good | Poor | Coat both faces, let dry, then press: bonds instantly. Solvent can attack some plastics, including acrylic. |
| Hot glue (EVA) | OK | Poor | OK | OK | OK | Poor | Poor | Poor | Good | Poor | Fast, temporary or low-load bonds. Softens in heat. |
| Acrylic solvent cement | No | No | OK | Poor | OK | Good | No | No | No | No | Solvent-welds acrylic to acrylic in close-fitting joints. Hazardous solvent: ventilate. |
| ABS cement / acetone | No | No | No | No | Good | No | No | No | No | No | Welds ABS to ABS (and ASA). Acetone also crazes acrylic and polycarbonate. |
| MS polymer / hybrid adhesive sealant | Good | Good | OK | OK | OK | OK | Good | OK | OK | Poor | Flexible, waterproof, bonds most things; slow to cure through. |
| Anaerobic threadlocker | No | Good | No | No | No | No | No | No | No | No | Metal threads only. Cures without air between metal surfaces; can crack many plastics. |
Good = a reliable choice; OK = works with good surface prep or for light loads; Poor = weak or unreliable; No = does not bond or damages the material. Ratings assume clean, dry, lightly scuffed surfaces. PETG and PP/PE are low-energy surfaces that most glues struggle with.
Cure Time, Gap Filling and Strength
| Adhesive | Working time | Clamp / handle | Full cure | Gap filling | Strength | Heat | Water | Tips and safety |
|---|---|---|---|---|---|---|---|---|
| PVA wood glue | 5–10 min open | 30–60 min clamp | 24 h | Poor | Very high on fitted wood joints (often stronger than the wood) | Moderate; can creep under constant load | Interior (D2) to water-resistant (D3) or exterior (D4) by grade | Choose a D3 or D4 rated glue (EN 204) for damp or outdoor work. |
| CA / super glue (thin) | Seconds | 10–60 s | 24 h | No | High in tension and shear, brittle in peel and impact | Moderate (many grades rated to about 80–120 °C) | Fair | Accelerator spray makes it instant. Bonds skin in seconds: keep acetone-based remover handy. |
| CA / super glue (gel) | 15–60 s | 1–2 min | 24 h | Poorsmall gaps | As thin CA | As thin CA | Fair | Rubber-toughened grades resist knocks better. |
| Epoxy, 5-minute | 3–5 min | 15–30 min | 24 h | Good | Good, more brittle than slow epoxy | Lower than slow epoxy; check the label | Good | Mix exact ratios. Fast epoxies are weaker and less heat-resistant. |
| Epoxy, slow-setting (30 min+) | 20–90 min | 6–24 h | 1–7 days | Goodexcellent | Highest of the common hobby glues | Better than fast epoxy; some grades much higher | Excellent (marine grades) | Warmth speeds the cure; below about 10 °C it may not cure properly. |
| Polyurethane (expanding) glue | 15–20 min | 1–4 h clamp | 24 h | OKfoam is weak | High on wood when clamped tight | Good | Waterproof | Dampen one surface. Clamp firmly or it pushes the joint apart. Stains skin for days. |
| Contact adhesive | 10–20 min to touch-dry | Instant on contact | 24–72 h | Poor | Good in shear on large flat areas | Can creep or let go in heat | Good | No repositioning once surfaces touch. Solvent types are flammable: ventilate. |
| Hot glue (EVA) | 10–60 s | Under 1 min | Under 5 min | Good | Low | Poor: softens from about 60–80 °C | Good | Low-temperature sticks are kinder to foam and thin plastics. |
| Acrylic solvent cement | Seconds–1 min | 1–5 min hold | 24–48 h | Nothickened grades fill small gaps | High: the joint is welded | As the plastic | Good | Usually dichloromethane-based: use only with ventilation and suitable gloves, away from children. |
| ABS cement / acetone | Seconds–1 min | Few minutes | 24 h | Poor | High: the joint is welded | As the plastic | Good | Dissolved ABS in acetone (“ABS slurry”) fills small gaps on prints. |
| MS polymer / hybrid adhesive sealant | 10–20 min skin | Support for 24 h | Several days (about 2–3 mm per day) | Good | Medium, stays flexible | Good | Waterproof | Overpaintable. Good for bonding dissimilar materials that move. |
| Anaerobic threadlocker | Several minutes | 10–20 min handling on steel | 24 h | Poorthread gaps only | Low, medium or high by grade | Grade dependent | Good | Slower on stainless, zinc and other inactive metals; a primer speeds it up. |
Times are typical at about 20 °C. Cold slows every adhesive; warmth speeds them up. Always follow the product label, which overrides these general figures.
How to Use This Chart
- Find the two materials, then the glue that is Good for both. For wood to metal, that is epoxy or an MS polymer adhesive. For PLA to wood, epoxy or CA. For rubber to metal, CA (tight fit) or contact adhesive.
- Then check the joint. If the parts do not fit closely, choose a gap-filling glue (epoxy, MS polymer, hot glue). CA and PVA need parts that touch.
- Prepare the surface. Most failures are surface failures. Scuff with P120–P240 paper, wipe with isopropyl alcohol, and glue within the hour. Oily woods such as teak need a solvent wipe just before gluing.
- Think about the load. CA is strong in shear but brittle in peel and impact. Epoxy and PU handle mixed loads better. For anything holding weight overhead, use a mechanical fixing as well.
Worked example: gluing a PETG 3D-printed bracket to an aluminium plate. PETG is rated OK (not Good) for epoxy and CA, so prep matters: scuff both faces with P180, clean with isopropyl alcohol, design a little texture or a groove into the printed face, then bond with slow epoxy and clamp lightly overnight. If the joint will take real load, add two screws into heat-set inserts as well.
Gluing 3D prints
- PLA: CA for small parts, epoxy for large or loaded joints. Solvent welding PLA needs dichloromethane, which is hazardous; glue is the better choice.
- ABS and ASA: solvent-weld with acetone or ABS slurry for a joint as strong as the part. Ventilate and keep away from flames.
- PETG: the hardest of the common filaments to glue. Scuff well and use epoxy or a gel CA. Design a press-fit or screw joint where you can.
- TPU: flexible CA or contact adhesive. Rigid glues crack as it bends.
Safety: CA bonds skin instantly; keep it away from eyes and have debonder or acetone-based remover ready. Uncured epoxy is a common cause of skin allergy: wear nitrile gloves and do not let it touch skin. Solvent cements and contact adhesives give off flammable, harmful vapour. Ventilate well and read the safety data sheet.
Frequently Asked Questions
A slow-setting two-part epoxy is the strongest general-purpose glue for mixed materials, metal and gap filling. For close-fitting wood joints, PVA wood glue is just as strong, as the wood usually fails before the glue.
Super glue (CA) is the quickest and works well on tight-fitting PLA parts. For large, loaded or gappy joints, use two-part epoxy. Scuff the surfaces lightly first.
Use an acrylic solvent cement, which melts the surfaces together into a near-invisible weld. The joint must fit closely and be flat. Ventilate well, as these cements use strong solvents. Epoxy or CA work too but are less clear, and CA can leave a white bloom.
Very little sticks well. A super glue with a polyolefin primer is the usual hobby answer, and there are specialist structural adhesives for these plastics. Otherwise use a mechanical fixing or a plastic weld.
Five-minute epoxy can be handled in 15–30 minutes and is fully cured in about 24 hours. Slow epoxies are handleable after 6–24 hours and reach full strength in 1–7 days. Cold slows the cure a lot.
No. Anaerobic threadlockers are for metal threads and can stress-crack many plastics. For plastic, use a nylon-insert locknut, a thread-forming screw or a heat-set insert.
Related Calculators and Charts
Ratings and times are typical values for common consumer and trade adhesives, drawn from general manufacturer guidance; formulations vary a lot between brands and grades. EN 204 durability classes (D1–D4) describe the water resistance of wood adhesives. Always follow the product label and safety data sheet, and test on offcuts before gluing a finished piece.