From time to time, we need to use a little metal in our DIY projects. But it can be impractical to bring out the soldering or welding gun every time, especially if it is a simple task and can be fixed with a little bit of adhesive.
Even if you have little to no experience working with metals, you must know that not any random household glue would work. The finished outlook would be sloppy and messy, not to mention that the product would easily snap apart. So how to glue metals? Well, the answer is to use metal glue, of course.
We’ll introduce you to the different types of glue before letting you in on the steps you must follow.
Types of Glue
While metal-bonding adhesives are easily available in your local hardware and home improvement stores, you cannot just walk in and pick one randomly. Each glue type has a specific use, and here are three kinds you need to know about.
Epoxy resin-based glues are extremely strong and form the sturdiest metal-to-metal bonds. They are mostly used in specialized creative projects, like costume jewelry besides the standard carpentry or woodwork.
Epoxy glue comes in different varieties as well. They may have different consistencies, visibilities, and setting speeds, and you can choose one according to the type of work you have.
Also, they have high heat and chemical resistivity and are therefore able to withstand grueling pressures. While they normally come in black, grey, or transparent colors, you can also add colorants and fillers for a seamless look.
To use this adhesive, combine equal parts of the hardener and glue and apply the mixture to the surface using an applicator tool.
There are also double chamber cartridges available in the market which conveniently mixes and dispenses the product for you. But you need to work fast because the bond might weaken if you do not assemble the parts within a minute or two.
After you have fused them back together, clamp them for at least an hour for the adhesive to set. And if you do not want to ruin your work, set aside the glued item for 24 hours before putting it out for service.
Polyurethane adhesive works great to bond metals with metals along with other materials. It is a thermosetting polymer that needs a little heat, usually room temperature, and a little moisture to set. Unlike epoxy, it does not need to be mixed with any other substance and can be used alone.
Once cured, it becomes water-resistant and UV-resistant and is super resilient. This makes this moisture-curing adhesive suitable for both interior and exterior use. They can also be sanded, stained, and painted to give your projects a cleaner and more polished finishing.
Besides, this glue is food-safe, so you can use it to repair your dining plates, kitchen items, or utensils. It also becomes slightly flexible after drying, so your products will be less susceptible to damage. Moreover, you do not need to rush to clamp your pieces together as this glue has a longer work time.
But this glue is not without its drawbacks. It forms weaker bonds than epoxy glue and is not as gap-filling either. It even has a shorter shelf life, but these demerits fall short when compared to the benefits.
Of course, we have the handy-dandy and ever-reliable super glue on our list. Made of ethyl cyanoacrylate, these super strong adhesives can be used to stick metal to metal or metal with other substances. Their bonding strength can reach up to 4,000 psi depending on the type of surface you are using it on.
These industrial standard adhesives can be used for most household repairs and fixes. They have a very short curing time, so they do not need more than a few minutes to set.
For this reason, DIY-ers love using superglues in their everyday tasks. They come with convenient dispensers, create no mess, and can be carried around easily, which makes for a hassle-free experience.
However, these bonds create even weaker bonds and need to be left touched overnight for maximum robustness. They do not fill the gaps and voids properly either, so you must make sure that pieces have a clean surface and form a perfect fit.
Some super glues even contain additives that create a very durable bond, even more than ordinary glues, which makes it perfect for various porous and non-porous substances. They dry out quickly, so make sure to keep the airtight caps on when not in use.
Now, you are up to speed with the different kinds of glue; it is time to learn which glue works best with which material. You do not have to purchase every kind of glue there is- only to have it wasting away.
How to Glue Metal
You can glue metal the same way you glue any other substances. But you need to take some extra steps and take precautions if you do not want to mess your work up and damage the items. The following step-by-step guide will provide you with a good idea of what you must do.
Step 1: Prepare your work Station
Before you start, you need to ensure you have all the right materials. The room must have good ventilation as adhesives can sometimes be toxic and cause difficulties in breathing. Drape your work surfaces with protective cloths or old newspapers.
You should also wear latex or nitrile hand gloves to keep your skin safe. Glue metals can be very abrasive on the skin, so wearing cotton, nylon, or PVC gloves might not really help.
Step 2: Prepare your surfaces
The surfaces of the substrates must be completely clean to ensure strong bonds. These materials are often subjected to high mechanical and thermal stress, so if they are not adequately clean, the adhesives will not work properly.
Make sure all kinds of oils, greases, dirt, and specks of dust are thoroughly scraped away. Even residues from older bonds should be wiped off. If rust forms, you need to remove them by grinding or sandblasting. However, remember to clean away any dust that might form.
You also want to roughen the surfaces up using fine-grit sandpaper to make the glue stick better.
Step 3: Apply the Glue
The back of the packaging has clear instructions for you to follow. Epoxy glues need to be mixed with hardeners and smeared using special tools.
But usually, all you must do is open the cap and squeeze the metal glue to apply on the prepared surface. You would not need more than one drop per square inch.
Just remember to keep track of the expiry date of your glue for it to work best.
Step 5: Join the Pieces
Position the pieces and press them firmly to form a tight seal. In some instances, you might have to clamp them together with firm pressure for about an hour. Different glues have different curing times, but if you want to get the maximum strength, leave them untouched for at least 24 hours.
Step 6: Clean away excess glue
After it has had time to dry, you need to assess your work to see if it needs to be touched up. Clean up any excess glue with acetone or mineral spirits. You can also use soapy water and diluted vinegar to scrub any spilled glue.
That’s it. The steps are super simple to follow and will make sure you get pristine results every single time!
Types of Glue to Bond Metals to Other Materials
The steps on gluing metal-to-metal and metal to other materials are almost similar, except for the types of glue used. You also might have to add a step or two, but those are optional. So, look at some of the other surface combinations you might work with.
1. Metal to Rubber
Cyanoacrylate-based adhesives, popularly known as superglues, work best with this combination because they create strong bonds which can be flexible as well.
Due to their high-performance formula, they have tensile strength and dry very fast. Take care to position them correctly the first time, as you might be unable to do so afterward.
2. Metal to Plastic
Working with metal and plastic can be a little tricky and may not produce the perfect results unless you know what to look out for. Not all glues can be used for plastic as they may not create sufficient bonds or end up damaging the surface. So, you need to ascertain the type of plastic you will be working with.
The best bet would be to use epoxies. They are resistant to most impacts, common solvents, chemicals, water, and heat.
3. Metal to Velcro
Superglue is the top choice when it comes to attaching metals with Velcro. They are waterproof and can be used on plastics and fabrics without causing any unwanted damages. If you do not want to use superglue, you can also try using other fabric-safe adhesives found in the market.
4. Metal to Glass
Both metal and glass non-porous, so it can be frustrating to work with them. But both cyanoacrylate-based adhesives and epoxies can be ideal in this situation. You should choose one that dries clear for a more pristine finishing.
The former is more suitable for smaller and interior projects. On the other hand, the latter forms a more weatherproof bond and gives you more time to position your substrate and set them.
5. Metal to Wood
When it comes to gluing metal to wood, you should always go for polyurethane-based adhesive. Because woods can be a little tricky to work with due to the density and porosity, only this moisture-curing adhesive can work properly here.
These are the most common surfaces you would be working on within your projects. Make sure you have the right kind of adhesive, or all your efforts would be in vain.
How to Choose the Best Metal Glue
Now that you know what kind of glue you need to pick up from the store, it is time for you to know the little factors you must take into consideration before making a purchase.
1. Drying Time
The curing and drying time for each metal glue can vary from a few hours to even 24 hours. You need to calculate how fast you must work or what is an acceptable range for you. The drying time is indicated in the product description, which will give you a clear idea.
2. Pressure and Impact Resistance
When you are working with metals, your final products should be strong and durable. And for that, your glue needs to able to handle extreme pressure and resistance. They also should be a little flexible to withstand high heat and temperature without collapsing.
3. Ease of Use
Glues can be messy to work with, and the clean-up can be a nightmare. So, you need to use glue that should be convenient to apply. We have already mentioned how much of a nuisance epoxy can be, but you can get double-chambered cartridges to help you out.
You should also keep an eye out for glues that come with nozzles for a precise application.
4. Element Exposure
Are you working outside or inside? What will you be using it for? These are the things you should consider before choosing your glue. The adhesive must be weatherproof and water and heat resistant if what you are working on needs to be placed outside.
If you need to use the glue on kitchen items, it should be food-safe and non-toxic as well.
5. The material of the Substrates
We have already talked about the different types of glue you need to use on the pieces you will be fusing. You need to consider the gaps you must fill, the color, and their fitting too.
If you do want to invest in a welding or soldering iron, metal glue is your best choice here. They are super strong and are just as good. Whether you want to glue metal to metal or metal to other materials, the right type of glue would wonder for you.
So, if you are worried about how to glue metals, take a look at our little buying guide and step-by-step gluing instructions to help you out.