Guide To Glue On Metal

Metal surfaces are notoriously tricky to glue because they're non-porous, prone to rust, and expand or contract with temperature changes. So, how do you get a strong, lasting bond? In short, it comes down to choosing the right glue for the job, preparing surfaces correctly, and giving the adhesive enough time to cure properly. In this guide, we’ll cover top metal adhesives and share tips for tackling everything from metal-to-metal repairs to bonding metal with glass, wood, plastic, and more.

‍

Which Glue Works Best on Metal?

There’s no single “best” glue for metal. Most glues can form effective bonds, but there are better metal adhesives for different projects.

Polyurethane adhesives (like Gorilla Glue), cyanoacrylate adhesives (like Gorilla Super Glue), contact adhesives, silicone adhesives, and epoxy adhesives (like Gorilla Epoxy) all work for metal bonding in different scenarios.

Here’s what to consider

• Drying time: If you need to work quickly and precise placement isn’t critical, a fast-acting adhesive is the best choice.
• Environment: Will the finished item be outdoors, exposed to moisture or extreme temperatures? Waterproof or weather-resistant formulas matter here.
• The other surface: Are you bonding metal to plastic, wood, or rubber? Different materials require different adhesives to bond effectively.

Steps For Bonding Metal Surfaces

1. Clean both surfaces thoroughly: Start by cleaning both surfaces to remove dust, oil, and dirt that could weaken bonding.
2. Apply your adhesive: Follow the product instructions, and don't over-apply the glue. You may need to mix the product before applying it.
3. Join your pieces: Firmly join the items you’re glueing and apply clamps if necessary to ensure the two surfaces will bond well.
4. Clean up as you work: Excess glue can be unsightly and a nuisance to clean up once dried. Use a dry cloth to wipe it away before it sets and follow any on-pack clean up instructions.
5. Don’t neglect curing time: A common reason for weak or broken bonds is not allowing your adhesive to cure fully. Even if it is dry to the touch, remember that most glues need at least 24 hours to cure before you should handle it.

Top tip: Adhesives need a “grip” to work, so smooth surfaces like metal can be challenging to glue. Use fine-grit sandpaper to lightly sand metal surfaces before glueing to help create stronger bonds. However, we do not recommend sanding delicate surfaces as this could cause damage.

Glueing Metal to Metal

Polyurethane, super glue, and epoxy all work exceptionally well for bonding metal surfaces together. The most important factors to consider are water resistance and the size of the items you’re glueing.

All three will work for more minor indoor repairs, but if you’re glueing large metal pieces or items that will be exposed to moisture or high temperatures, use PU glue or epoxy glue. Here are some tips to keep in mind:

• Surface preparation: Thoroughly clean both metal surfaces, remove any grease, and sand each surface to create a rougher texture. We do not recommend sanding delicate surfaces as this could cause damage.
• Clamp time: Keep the metal pieces clamped together while they dry to form the strongest bond.

Glueing Metal to Rubber

Rubbers with high oil or plasticiser content can be difficult to glue. For smaller projects, a cyanoacrylate-based adhesive, such as Gorilla Super Glue, will give you a flexible, strong bond. However, it is not waterproof, so if that’s a concern, consider a fast-drying contact adhesive.

Glueing Metal to Plastic

Some plastics don’t bond well with certain glues and can even be damaged by adhesives.

Start by identifying the type of plastic you’re working with. Look for the material type symbol and check if there is a number and abbreviation that tells you what the plastic is made of.

Epoxy should provide a robust, dependable bond for glueing most plastics to metal, and other adhesives (like super glue) can also work. Please note that these adhesives are unsuitable for use on polyethylene (PE) and polypropylene (PP) plastics.

Remember to always check compatibility beforehand. If you’re unsure, contact the Gorilla consumer affairs team via the contact page for specific guidance.

💡Learn more: Guide To Glueing Plastic

Glueing Metal to Glass

Clear epoxy glue is a good option when you need to bond metal to glass. It’s known for glueing smooth surfaces like metal and glass, has a relatively short setting time (5 minutes) for aligning and adjusting, and will create a rock-solid, permanent bond.

Top tip: Avoid leaving fingerprints or oily residues on glass pieces, as these can weaken the bond. Clean both surfaces thoroughly and wear gloves.

💡Learn more: Guide To Glueing Glass

Glueing Metal to Wood

Wood and metal expand at different rates depending on humidity and heat, so you’ll need a strong but flexible adhesive.

The best option is a polyurethane-based adhesive, such as Gorilla Glue, which is expanding, temperature-resistant, and reliable. You can also use Gorilla Epoxy, Gorilla Grab Adhesive, and Gorilla Super Glue. However, we do not recommend using wood glue for metal bonding, as it works best with porous materials.

💡Learn more: Guide To Glueing Wood

‍

Wrapping It Up

When in doubt, always check the product instructions or perform a small test run to see how well your glue works before using it on metal surfaces. For a lasting bond on mixed materials, choose the right adhesive for the job and consider the environment your glue will need to handle. Don't neglect surface preparation, and always let your adhesive cure properly to create strong, durable bonds.

Visit the Gorilla Glue blog for more advice, guides, and tips on how to get the most out of your adhesives.

‍