How To Join Metals Without Welding

Attaching pieces of metal together is necessary for a variety of situations.

Welding is a popular way to do this, but there are a range of other methods which can also be used.

These include techniques, such as soldering, brazing and riveting, along with the use of adhesives or even nanomaterials.

Welding-The Basics

Man Welding

Welding is the process of heating two pieces of metal and fusing them together to form a secure bond.

During this process, it is possible to add a filler or a flux whilst applying the heat.

A filler is another piece of metal that is supplied from a welding rod, which seals up any small gaps between the two metal surfaces.

Flux is a non-metal chemical that helps prevent the molten metals from producing oxides or nitrates with gas in the air—which can weaken the bond.

Welding involves the use of heat.

This can come from a number of different sources, including oxyacetylene gas, electrodes, lasers, ultrasonics and electron beams.

Should You Always Join Metals This Way?

When you want to join two metals together, welding may not always be the best solution.

Welding can be dangerous to carry out, due to the risk of electric shock, burns from the high temperatures, and issues from toxic gases.

It is also an expensive process because of the cost of required materials, tools and labor.

Welding forms an extremely strong bond between two metal surfaces.

This is useful for processes where the bond has to withstand a huge amount of stress. Examples of this include joining the components of a car, boat or piece of machinery.

However, there are many situations where an alternative to welding is useful, as a bond of this strength simply isn’t always necessary. These include fusing the components of an electrical circuit, or joining metals which cannot withstand the heat used during welding.

Another example of when welding is not ideal, is creating a base to support the load of a structure which sits at a perpendicular angle to the location of the join.

What Are Some Alternative Ways to Join Metals?

There are numerous methods of joining metals without welding.

Some of these still require heat, but at lower levels, while others involve different kinds of adhesive technology.

Nanomaterials

Joining Metal With Nanomaterials

The use of nanomaterials, or nanoscale sculpting, is a very new method of joining metals, which is still being developed.

It involves roughening the metal surface with a specific etching method, done by using electro chemicals and 3D printing.

This results in a fine hook-like structure being created on an extremely small scale. Two of these surfaces are then joined using adhesive, which creates a very strong bond.

This technique can be used to join large and heavy components together, in applications such as the building of cars and ships.

It eliminates the need for high temperatures that can damage surfaces, especially those that are already treated or painted.

Instead, nanoscale sculpting can be carried out at room temperature and doesn’t require the same number of safety measures.

As this method develops, there is the potential for it to be used in any number of applications.

These include joining combinations of metals which are unable to be bonded using current methods. This means many new applications may become possible, especially in medical technology.

Pros

  • Process is performed at room temperature
  • Less risk than heat-based methods
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    Forms a very strong bond between surfaces
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    Has the potential to be used in a range of applications

Cons

  • The method is still in development and not yet fully tried and tested

Glue

Glue Gun

Using glue to join two metal surfaces is a simple process. It involves applying a certain adhesive to the surfaces requiring joining, and pressing them together to form a bond.

A range of adhesives are suitable for metals, including silicone based, epoxy, polyurethane and even double-sided tape.

There are many new products for this purpose which are constantly being developed. Some adhesives contain microscopic nanorods with metallic cores of different types.

The surfaces to be joined are treated with this product, and the different metallic cores fuse together to produce a strong bond.

Pros

  • Glue is cheaper than heat-based methods
  • Less risk involved in the process of using adhesives

Cons

  • Using glue to join metal surfaces forms weaker bonds than heating methods, so it is not suitable for all applications

Soldering

Soldering Components

While soldering may seem like a similar process to welding, it forms an electrical connection between metals, instead of a mechanical connection. This means that the bond isn’t as strong, structurally.

Solder is a substance which looks like coiled wire. It is a soft metal alloy, which is a mixture of metals.

A typical solder is made up of around 99 percent tin, although other metals, such as copper, silver, zinc and bismuth can also be part of it.

This alloy melts at a low temperature, therefore soldering is performed using a lower heat compared to welding.

Instead of melting the metal pieces that will be joined, with soldering, the filler metal is melted instead, and used as a bond in the middle.

Soldering is a particularly good method for using on electrical circuits. The separate components in a circuit include small devices, like transistors, resistors, capacitors and LEDs. All of these have their own specific job.

These devices are assembled to make many different parts for electrical products, such as calculators, radios, TVs and computers.

The terminals of these devices could be wired together with electrical cables in order to connect them into a circuit. However, these wires can come loose or fall off.

This would break the circuit and the product would not function successfully. Soldering gives a circuit a much more effective and reliable electronic connection.

Pros

  • Safer than welding
  • Bond is created at a lower temperature
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    Makes an electrical connection which is useful for circuit-based devices

Cons

  • Forms an electrical connection, instead of a stronger mechanical connection
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    Not for use in all applications due to a weaker bond

Brazing

brazing guide

Like welding and soldering, brazing also involves the process of melting metal in order to join two pieces of metal together.

When brazing, the filler metal functions more like an adhesive. The filler component for brazing can be made up of various different metals, depending on the required application.

Some of these include:

  • Copper-phosphorus
  • Silver
  • Aluminum-silicon
  • Magnesium
  • Cobalt
  • Nickel
  • Precious metals

As these metals have a higher melting point than tin, the process of brazing is performed at a higher temperature than soldering.

This means that the metals you are joining are also affected by the heat, and the filler metal bonds them together securely.

When soldering, the metal surfaces don’t actually melt as the temperature is too low; the solder simply sits between them and forms the join.

Therefore, brazing is like a mix of welding and soldering. It produces a strong mechanical joint, as the metal surfaces melt as well as the filler substance.

Pros

  • Causes a strong mechanical bond, similar to welding
  • Performed at a lower temperature than welding
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    Suitable for a variety of different applications

Cons

  • The join is not as strong as welding, due to the filler metal being softer

Riveting

Riveted Metal

Riveting is the process of using mechanical fasteners to form a permanent bond between two metal surfaces.

It is shaped like a screw or a nail, with a shaft shaped like a cylinder, and a head on one end. This is placed through a pre-drilled hole, and then the tail of the rivet is pounded so that it flattens and expands until it is wider than the shaft.

The rivet is held in place by the thicker end, and thus effectively joins two metal surfaces together without the use of heat or glue.

This method can be used for tension loads, where the join has to withstand opposing forces. Overall, bolts and screws are the better method for supporting tension loads, however.

Riveting is extremely good for supporting shear loads, which sit at a perpendicular to the axis of the rivet shaft.

It is commonly used in construction projects which use lightweight materials that require strong joins. It is also used to produce chassis for cars.

Generally, riveting is preferred over welding for joining sheet metal alloys, as the high heat can cause the metal to deform and change its material properties.

Pros

  • Very useful for supporting shear loads
  • Better than welding for joints that will be subject to vibration and impact forces
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    No heat required
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    Good for joining lightweight metals together strongly

Cons

  • Joints are not leakproof and can leave gaps

Final Thoughts

Metal Welding

The process of welding forms an extremely strong bond between two pieces of metal.

While this has many benefits, it can also be potentially expensive and dangerous. In some instances, when bonding metal, welding is not completely necessary.

Here we have listed a variety of alternatives to welding that can be used to join metal. Each of these has its own positives and negatives, but there is something for every situation.

Hopefully, now you can find the right technique to suit your needs, no matter what kind of metal you will be joining.

About the Author Gregory

Hi, my name is Gregory! I have been welding practically all of my life and love it. As I have gotten older I have started to weld less and less, so in order to continue my love for welding I created this website. I like to write about my experiences and help you all become welders. I hope that you enjoy the site!

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