Despite the traditional methods of welding and soldering being extolled as the best joining methods, metal glueing has begun garnering a strong reputation as an alternative. To help you understand this change, we’ll break down how to properly approach glueing metals together.
Why glueing?
Firstly, it’s worth knowing why we’re veering away from the sacred joining methods of old. Not only do metal adhesives allow for versatility – in situations where the high-temperature alternatives may not be optimal – but they can easily be applied for DIY projects.
But don’t go rushing to your tool shed just yet – metal adhesives aren’t a one-glue-fits-all solution to your joining problems. Different metals react differently, with aluminium and copper having completely different reactions to adhesives based on chemical composition and texture.
It can be difficult to find the right adhesive for inexperienced or DIY joiners, but expert advice and services for metal bonding adhesive can be found online, for example at https://www.ct1.com/product-applications/metal-to-metal-adhesive.
Preparation
Before glueing, you need a smooth surface. For the best quality surface, you need to clean, abrade, prime, and then clean again. Your first clean should remove any grease and rust, and then the abrading creates a grittier surface capable of gripping the glue. Sometimes, applying a compatible primer will boost adhesion, though you can still just skip to the second cleaning, simply wiping down the surface with a cloth.
Adhesive Types
This is the most important part of the process, with the wrong adhesive potentially ruining your join. The three main adhesives are epoxies, polyurethanes and cyanoacrylates. Epoxies are strong and versatile, polyurethanes are flexible and cyanoacrylates, or superglues, are great for small, speedy repairs. A more detailed guide on adhesives and their differences can be found here.
Application
Start with a thin, even layer of your chosen adhesive, ensuring it is not too thick. Next, align the two metals, then press them together with enough force to spread the adhesive, but not so much that it is forced out. Using clamps can help with fiddlier applications. Finally, wipe down any excess adhesive, and allow it to set.