Which glue works on plastic?
Which glue works on plastic?
It depends entirely on which plastic — identify it first, because solvent cement is unbeatable on some and useless on others.
The dividing line runs between amorphous and semicrystalline plastics. Amorphous polymers — polystyrene, ABS, PVC, acrylic, polycarbonate — have disordered chains that solvents can get between, so solvent cement softens both faces and they fuse as it evaporates, giving a joint as strong as the parent material. Semicrystalline polymers such as polypropylene, polyethylene, acetal and nylon have ordered regions that resist solvents entirely, which is why the same tube does nothing. Identification is therefore the first job, and the recycling triangle on the part usually gives it away: 1 is PET, 2 HDPE, 3 PVC, 4 LDPE, 5 PP, 6 PS, 7 everything else including polycarbonate.
The options, ranked
| Option | Good at | Bad at |
|---|---|---|
| Solvent cement | Dissolves and fuses the two surfaces into one piece on ABS, PVC, polystyrene, acrylic and polycarbonate. A weld, not a glue. | Does nothing at all on polypropylene, polyethylene, acetal, nylon or PTFE, because no practical solvent dissolves them. |
| Cyanoacrylate (superglue) | Fast, strong in shear on rigid plastics with a close fit, and a rubber-toughened grade handles some flex. | Brittle, poor in peel, fogs clear plastics with its vapour, and can trigger stress cracking in acrylic and polycarbonate. |
| Two-part epoxy | Gap-filling, rigid, and works on a wide range of plastics after abrasion — the safe default when the plastic is unknown. | Rigid, so it fails on anything that flexes, and still fails on polyolefins. |
| Methyl methacrylate structural adhesive | The professional answer: bonds dissimilar plastics including some polyolefins, tough and flexible. | Sold in cartridges with static mixers, smells strongly, and is expensive for a household repair. |
| Plastic welding | The only genuinely structural repair for polypropylene and polyethylene, using a rod of the same material. | Needs a hot air or extrusion welder and practice; a bad weld looks fine and is not. |
Technique that changes the outcome
- Read the recycling code moulded into the part before buying anything
- If there is no code, drop an offcut in water — polypropylene and polyethylene float, almost everything else sinks
- Abrade both faces with 120-180 grit and degrease with isopropanol
- Test on a hidden area or an offcut: solvents can craze a part days after they look fine
- Clamp lightly; solvent-welded joints need contact, not pressure
What goes wrong
- Superglue on stressed acrylic or polycarbonate — the vapour crazes the surface and cracks appear later
- Assuming a product labelled "plastic glue" covers polypropylene; almost none do
- Gluing anything that will hold hot food or drink; almost no consumer adhesive is food-safe
Compiled practical guidance rather than a published standard. Product formulations vary by brand and market, so read the label — and where the work is structural, electrical or gas, the regulations that apply where you are govern rather than anything here.
Other glue and adhesive questions
| For | Use |
|---|---|
| Polypropylene and polyethylene | Ordinary adhesives cannot wet these plastics at all. Use a polyolefin primer with cyanoacrylate, an MMA structural adhesive, or weld the plastic. |
| Wood | PVA wood glue for anything indoors; a water-resistant grade (Type I / D4) or polyurethane for anything that gets wet. |
| Metal | Two-part epoxy for anything structural, cyanoacrylate for small dry parts, and MMA where the surface cannot be properly prepared. |
| Ceramic and pottery | Two-part epoxy for anything that will be handled or loaded, cyanoacrylate for a clean break on a display piece — and neither is dishwasher-proof. |
| Shoes | A flexible shoe repair adhesive — polyurethane or a neoprene contact cement — never superglue, which cracks within a day of walking. |
| Fabric | A washable fabric adhesive or a fusible bonding web — and never superglue, which reacts with cotton violently enough to burn. |
| Glass | UV-cure glass adhesive for an invisible joint, clear epoxy where it must hold load, and neutral-cure silicone where it must stay flexible or wet. |
| PVC pipe | PVC solvent cement with its matching primer — and PVC, CPVC and ABS cements are not interchangeable. |
| Tiles | A cement-based thin-set in almost every case; ready-mixed tub adhesive only on small dry walls, never on floors or in showers. |
| Phone screens | A pre-cut adhesive gasket, or a flexible B-7000-type adhesive around the frame — superglue destroys screens and is the classic mistake. |
| Rubber | Contact cement for large flexible areas and rubber-toughened cyanoacrylate for small ones — but silicone and EPDM need a primer or they will not bond at all. |
| Outdoor and waterproof joints | Polyurethane or epoxy for rigid joints, MS polymer where the joint has to move — and check the water-resistance class rather than the word "waterproof". |
| Acrylic (Perspex, Plexiglas) | A solvent cement run into the joint by capillary action — not a tube adhesive, which will always look like a repair. |
| Concrete | Epoxy or a construction adhesive for bonding to it, and a chemical anchor resin — not glue — for anything that carries load. |
| Leather | Contact cement for a permanent flexible bond, or a leather-craft PVA to hold pieces while you stitch them. |
| Silicone | Effectively only more silicone, and even that needs a primer — and any silicone residue left on a surface stops everything else sticking too. |
| Paper | A glue stick or PVA for everyday work; wheat starch paste or methylcellulose for anything you want to survive — and never tape. |
| Foam | A foam-safe water-based adhesive or low-temperature hot melt — solvent adhesives dissolve polystyrene on contact. |
| Polycarbonate | A urethane or silicone adhesive is safest; solvent cements work but polycarbonate is unusually prone to stress cracking days later. |
Common questions
- Which glue works on plastic?
- It depends entirely on which plastic — identify it first, because solvent cement is unbeatable on some and useless on others.
- What should I avoid?
- Superglue on stressed acrylic or polycarbonate — the vapour crazes the surface and cracks appear later Assuming a product labelled "plastic glue" covers polypropylene; almost none do Gluing anything that will hold hot food or drink; almost no consumer adhesive is food-safe
Related pages
- Which glue works on polypropylene and polyethylene? Ordinary adhesives cannot wet these plastics at all. Use a polyolefin primer with cyanoacrylate, an MMA structural adhesive, or weld the plastic.
- Which glue works on wood? PVA wood glue for anything indoors; a water-resistant grade (Type I / D4) or polyurethane for anything that gets wet.
- Which glue works on metal? Two-part epoxy for anything structural, cyanoacrylate for small dry parts, and MMA where the surface cannot be properly prepared.
- Which glue works on ceramic? Two-part epoxy for anything that will be handled or loaded, cyanoacrylate for a clean break on a display piece — and neither is dishwasher-proof.
- Which glue works on shoes? A flexible shoe repair adhesive — polyurethane or a neoprene contact cement — never superglue, which cracks within a day of walking.
- Which glue works on fabric? A washable fabric adhesive or a fusible bonding web — and never superglue, which reacts with cotton violently enough to burn.
- Which glue works on glass? UV-cure glass adhesive for an invisible joint, clear epoxy where it must hold load, and neutral-cure silicone where it must stay flexible or wet.
- Which glue works on PVC pipe? PVC solvent cement with its matching primer — and PVC, CPVC and ABS cements are not interchangeable.
- Which adhesive should I use for tiles? A cement-based thin-set in almost every case; ready-mixed tub adhesive only on small dry walls, never on floors or in showers.
- Which glue works on a phone screen? A pre-cut adhesive gasket, or a flexible B-7000-type adhesive around the frame — superglue destroys screens and is the classic mistake.
- Which drill bit should I use for plastic? Drill bit
- Which sandpaper grit for plastic? Sandpaper grit
- Which paint sticks to plastic? Paint
- Which screw should I use in plastic? Screw
Sources
- Typical range compiled from manufacturer specifications — At One Place