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Jul 02, 2023

Best glue for metal 2023: The adhesives that are the alternative to welding

You think joining metal requires welding, brazing or soldering? Well, think

You think joining metal requires welding, brazing or soldering? Well, think again. For many applications, metal glue could well be the answer, and it's even widely used in large-scale manufacturing – indeed, some car manufacturers use adhesives to fix body panels to their cars’ chassis.

That means there's plenty of choice out there for the home DIYer. With several different types of glue available, it's possible to glue many different types of metal. Some glues are fast drying, others can take many hours to cure properly. Some can be used to fill gaps and the excess glue can be filed away, while others offer good resistance to heat or chemicals. You can even use some metal glue as thread lock to stop screws and bolts from working loose.

With so many different brands out there, we’ve rounded up some of the most highly respected of each type, taking into account specific properties, drying time, cost and online user reviews.

READ NEXT: The best super glue

Yes. Super glue will stick metal almost instantly (it will stick your fingers to it too, so take care). It works better on reactive metal, such as brass and copper, than it does on steel, but super glue's fast-drying nature has wide appeal, particularly with model makers. However, it's worth noting that unlike epoxy or polyurethane glue, super glue can't fill in cracks and holes.

Cyanoacrylate-based super glues are suitable for adhering metal to metal, metal to certain kinds of plastic, and metal to glass.

Epoxy metal glue will come in two tubes, or a single dispenser with two chambers. You’ll need to squeeze out the required amount of glue onto a piece of card or a scrap of wood, and mix the epoxy adhesive with the hardener to start the curing process. Typically, epoxy glue, such as those from Gorilla or Araldite, can take many hours to fully harden, but others only take a few minutes.

Either way, you’ll have to ensure the parts are held together well but, once it's set, it forms an exceptionally strong bond and any excess glue can be cut away or sanded.

Epoxy glue is excellent for metal to metal, metal to plastic, and metal to glass applications.

Polyurethane glues are another common option. They’re resistant to both water and UV rays and dry quickly without becoming brittle, making them an excellent choice for outdoor use. They’re equally useful indoors, too, because they resist heat well.

Polyurethane glue is good for adhering metal to metal and, because of the strength and flexibility it exhibits, it's able to glue wood to metal.

Drying time varies enormously between types of glue and brands of glue. Indeed, the time it takes to dry may well determine which option you choose. In the case of super glue, it could take a matter of seconds, while polyurethane could take a couple of hours. Rapid-drying epoxy glues that only take around an hour are available, but more traditional epoxy offerings will require eight hours or more.

READ NEXT: The best wood glue

Price: £6 | Buy now from Amazon

Gorilla brand glues are some of the biggest selling in the UK market, and its epoxy glue is the most highly regarded across a number of online retailers. It's easy to use the two-part syringe to dispense equal parts of resin and hardener, and the cap only fits one way so you can't inadvertently glue it on permanently. There's also a mixing tray moulded into the blister pack, if you need it.

To use, squeeze out an equal amount of resin and hardener then mix using the supplied spreader for a minimum of 20 seconds before applying to the surface to be glued. As long as it's applied within five minutes, you can expect it to fully cure in around 24 hours, at which point the bond will be permanent.

Key specs – Container size: 25ml; Set time: 5 minutes; Full cure time: 24 hours

Price: £4.50 | Buy now from Amazon

Like super glue, UniBond and No More Nails have practically become generic terms for heavy-duty adhesive that's suitable for bonding pretty much anything, from wood to concrete, ceramics and, of course, metal. Unlike the other glues here, No More Nails comes in a large tube, so it's possible to apply it generously to ensure maximum adhesion.

Though UniBond promotes its "instant grab" qualities, it's actually repositionable for up to five minutes, allowing you to get the perfect finish. It will fill gaps up to 10mm and can be painted over once dry – and any excess can be wiped away with a dry cloth while it's not. And although we’ve focused on the interior glue here, there are exterior, waterproof versions in the firm's extensive range.

Key specs – Container size: 234g; Set time: 5 minutes; Full cure time: 24 hours

Price: £1.70 | Buy now from Amazon

When you think of super glue, it's probably Loctite's version that first springs to mind. It comes in a tiny bottle, but for most jobs you’ll need little more than a single drop – the bottle will probably dry out before you use it up.

Loctite boasts "instant strength in a drop", meaning that while whatever you’re glueing ostensibly requires pressing together for a minute to set, the reality is that it will only take between five and 30 seconds – as anyone who has stuck their fingers together will attest. Super glue dries clear, though care needs to be taken not to apply too much as it's possible to see the excess once dry, and its fast setting time means it's extremely difficult to wipe away. Still, once glued, your objects are unlikely to come apart.

Key specs – Container size: 5g; Set time: 1 minute; Full cure time: 1 hour

Price: £6.56 | Buy now from Amazon

Araldite is one of the oldest names in the business: the first batches of its epoxy resin were made at Duxford, Cambridgeshire in 1950 and it was used extensively to bond Donald Campbell's land-speed record car a decade later. More recently, Lamborghini used it on its Aventador supercar.

The "Rapid" formula is supplied in a twin-chamber syringe which makes it easy to mix using the tray in the blister pack. Once done, you’ve four minutes to reposition it, and any excess can be trimmed away with a sharp knife while it's partially set. It reaches full strength after two hours – significantly less than the 14 hours recommended for the "Standard" formula. Still, while it's not the fastest-drying glue on the market, it's extremely versatile – it's suitable for a wide range of metals, it can be sanded, cut, and reshaped, and it can withstand temperatures ranging from -30 to 65°C.

Key specs – Container size: 24ml; Set time: 20 minute; Full cure time: 2 hours