To quickly fix a cracked or broken plastic container, clean and sand the edges. Secure the pieces, then apply a strong, plastic-rated adhesive—such as a 2-part epoxy, plastic glue, or a super glue and baking soda mixture. For added strength, reinforce the joint by layering a mesh patch or staple across the crack.
To begin:
Selecting the right adhesive to repair cracked plastic
Our favourite is Loctite Super Glue All Plastics. This specialty super glue is designed for plastics, including the hard-to-bond-to polypropylene and polyethylene. It comes with an activator which you apply first and need to allow to dry for 60 seconds.
To fix a hairline crack in plastic, use a fast, permanent bond by applying super glue (cyanoacrylate) along the crack, followed by baking soda to create a rock-hard weld. Alternatively, melt a shallow groove on the back with a soldering iron to fuse the edges together.
For repairing and bonding most plastic materials, including ABS, hard plastic, soft plastic, PVC and fiberglass, the strongest adhesive to use is Loctite Epoxy Plastic. Its 2-part formula consists of resin and hardener.
Original Gorilla Glue struggles to bond with plastic because plastics are non-porous and have low surface energy. This prevents the polyurethane glue from penetrating, wetting, or forming a chemical grip. Furthermore, regular Gorilla Glue expands as it cures, which easily breaks the bond.
Epoxy Adhesives for Plastic - Strongest Bonds
Epoxy is typically the product of a chemical reaction between two compounds- hardener and resin. They are probably the strongest glue for plastic and can also be used on a range of other materials. They also have great chemical resistance.
J-B Weld has a wide assortment of adhesives that are ideal for repairing plastic. J-B Weld products are easy to use, versatile, and permanent. For plastic repair projects that are functional and aesthetic, JB Weld has a product designed for your needs.
"It tends to soften certain plastics, making them brittle. I've seen prefab cabinet hinges degrade after a tenant tried 'fixing' a squeak with it."
To make a crack in plastic disappear, your best approach depends on whether you need a cosmetic fix (like an appliance or trim piece) or a structural repair. For minor hairline cracks, use a specialized solvent cement (like acrylic glue) or a super glue and baking soda hack, followed by sanding and painting. For deep structural cracks, use a soldering iron to plastic weld the pieces back together.
Fixing broken plastic without glue relies on plastic welding or thermal reshaping, which melt the edges to fuse the material back together. This technique creates a stronger, permanent bond compared to adhesives, yielding a repaired piece that is structurally solid and functions as a single unit.
Plastic sealant glues are specialized adhesives designed to bond, mend, and waterproof plastic materials. The right choice depends on the type of plastic (e.g., hard PVC vs. flexible polyethylene) and whether the repair needs to remain flexible or withstand weather and water.
Infinity Bond MMA 500 is a very unique two-part methacrylate adhesive that bonds difficult plastics like Polyethylene (PE) and Polypropylene (PP) better than almost anything on the market.
To seal a crack in plastic, use a two-part plastic epoxy (like J-B Weld Plastic Bonder or Loctite Plastic Bonder). For a more permanent structural fix, you can also use a plastic welding kit with metal staples, or a solvent weld if the plastic is ABS.
Combining super glue (cyanoacrylate) and baking soda creates a rock-hard, sandable plastic weld ideal for repairing cracks, filling gaps, and rebuilding tabs. When mixed, the baking soda acts as an accelerator and a reinforcing filler, instantly curing the liquid glue into a durable, cement-like composite.
What is the best sealant/epoxy for a bathtub hairline crack? The ideal repair material is a two-part epoxy or resin designed for your tub's surface type, whether acrylic or fiberglass.
Yes, standard WD-40 Multi-Use Product can damage certain plastics over time. Its petroleum-based solvents act on polymers, which can cause soft plastics to swell or degrade and amorphous plastics (like polycarbonate and polystyrene) to crack or craze.
Dish soap is expected to effectively remove WD40 stains!
While WD-40 is a great multipurpose solvent, it is a poor long-term lubricant and should never be used on items that require specialized lubricants, come into contact with food, or are made of sensitive plastics and rubber.
The best glue depends on the type of plastic. For most rigid and semi-flexible plastics, the top choice is J-B Weld Plastic Bonder. For delicate items or difficult-to-bond plastics (like polyethylene), use a two-part kit with a surface activator, while simple, fast cracks are best handled by a rubber-toughened super glue.
Avoid using J-B Weld on items that are flexible, food-safe, exposed to direct open flames, or made of certain plastics. It is a rigid, two-part epoxy, meaning it will crack or fail on materials that bend or stretch.
Loctite Plastics bonding system is a two-part cyanoacrylate adhesive that sets in seconds and develops tremendous strength with just one drop. The activator primes hard-to-bond surfaces such as polypropylene and polyethylene. Loctite super glue plastics bonding system dries clear and sets without clamping.
Gorilla Glue is incredibly strong, forming a permanent bond that is often stronger than the materials being joined. However, its strength depends heavily on using the right type of Gorilla product (Original, Super Glue, Epoxy, or Wood Glue) and following specific moisture and clamping requirements for the best hold.
If the plastic is hard like a bucket or milk crate, it is likely to be polyethylene or polypropylene. These plastics are nearly impossible to glue unless you choose an adhesive that is marked specifically for use with polyethylene or polypropylene.