---
title: "Which glue works on polycarbonate?"
description: "A urethane or silicone adhesive is safest; solvent cements work but polycarbonate is unusually prone to stress cracking days later. The ranked options, the technique"
url: https://atoneplace.net/which/glue-polycarbonate/
site: "At One Place"
---

# Which glue works on polycarbonate?

**Which glue works on polycarbonate?: A urethane or silicone adhesive is safest; solvent cements work but polycarbonate is unusually prone to stress cracking days later.**

Polycarbonate is exceptionally tough — it is what riot shields and machine guards are made from — and exceptionally vulnerable to environmental stress cracking. Where the material is under tension, whether from moulding, from a screw done up too tight, or from being bent into place, certain chemicals dramatically lower the energy needed to start a crack, so a part can fail days after contact with something that seemed harmless. Ammonia-based glass cleaner is the classic domestic example; acetone, MEK and many solvent adhesives are worse. Because polycarbonate also expands and contracts far more than glass with temperature, glazing details are designed to let sheets move, and bonding them rigidly is what makes them craze at the fixings.

## The options, ranked

*Ranked best-first for the stated job. The third column is why the others exist.*

| Option | Good at | Bad at |
| --- | --- | --- |
| Two-part urethane adhesive | Tough, slightly flexible and does not attack the polymer, so it avoids the stress-cracking trap entirely. | Visible glue line and a slower cure than solvent methods. |
| Neutral-cure silicone | The standard for glazing polycarbonate sheet, because it accommodates the sheet's large thermal movement. | Low strength; it seals and retains rather than structurally bonds. |
| UV-cure adhesive | Clear, controllable and formulated in grades specifically for polycarbonate. | Requires light access and the right lamp. |
| Solvent cement | Gives a genuine weld where the parts are annealed and unstressed. | Any residual stress plus solvent equals crazing and cracking, often appearing after the job looks finished. |
| Cyanoacrylate | Fast for a tiny non-visible tack. | The vapour fogs the surface and its heat and chemistry readily start stress cracks. |

## Technique that changes the outcome

1. Relieve stress before bonding: anneal machined parts to the supplier's schedule if the joint matters
2. Clean only with warm water and a mild detergent, or a cleaner the sheet manufacturer names
3. Leave clearance in fixing holes so the sheet can expand — do not pinch it
4. Test any adhesive on an offcut and leave it a week before trusting it

## What goes wrong

- Ammonia-based glass cleaners, acetone, MEK and most aggressive solvents
- Superglue on a stressed or visible surface
- Over-tightening screws through polycarbonate, which builds exactly the stress that cracks it

> 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 |
| --- | --- |
| Plastic | It depends entirely on which plastic — identify it first, because solvent cement is unbeatable on some and useless on others. |
| 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. |

## Common questions

### Which glue works on polycarbonate?

A urethane or silicone adhesive is safest; solvent cements work but polycarbonate is unusually prone to stress cracking days later.

### What should I avoid?

Ammonia-based glass cleaners, acetone, MEK and most aggressive solvents Superglue on a stressed or visible surface Over-tightening screws through polycarbonate, which builds exactly the stress that cracks it

## Related pages

- [Which glue works on plastic?](https://atoneplace.net/which/glue-plastic/)
- [Which glue works on polypropylene and polyethylene?](https://atoneplace.net/which/glue-polypropylene/)
- [Which glue works on wood?](https://atoneplace.net/which/glue-wood/)
- [Which glue works on metal?](https://atoneplace.net/which/glue-metal/)
- [Which glue works on ceramic?](https://atoneplace.net/which/glue-ceramic/)
- [Which glue works on shoes?](https://atoneplace.net/which/glue-shoes/)
- [Which glue works on fabric?](https://atoneplace.net/which/glue-fabric/)
- [Which glue works on glass?](https://atoneplace.net/which/glue-glass/)
- [Which glue works on PVC pipe?](https://atoneplace.net/which/glue-pvc-pipe/)
- [Which adhesive should I use for tiles?](https://atoneplace.net/which/glue-tile/)

## Sources

- Official vendor product documentation — At One Place (/about/)