How to bond metal without welding

We're all familiar with the classic types of welding like gas welding, arc welding or spot welding.

But there is another way to bond two metal surfaces – by applying a cold weld compound. This type of metal epoxy adhesive comes in two parts and does not require the use of a welding torch or machine. Instead, it relies on the chemical reaction that occurs when the two solutions are mixed. The resulting product can be used to create an instant bond between two surfaces.

You don't need any skills to use a cold weld compound. Simply read the product instructions provided and follow them to the letter. This type of product is usually supplied as a two-part epoxy adhesive. The two parts must be mixed together to obtain the bonding solution. This type of product can be used for the following repairs:

• repairing broken objects;

• minor plumbing repairs;

• patching up leaks;

• repairing cracks;

• strengthening surface weaknesses.

Whether you are carrying out repairs or assembling parts, the success of your bond all comes down to choosing the right product. It's a good idea to have a multi-purpose epoxy adhesive on hand to deal with any unexpected repairs. Epoxy adhesive can be applied to metal, wood, cast iron, stone, and many other materials, and it is heat-resistant. However, if you want your repairs to last, it's important to select the right type of product for your needs. For example, you can find adhesive designed specifically for:

• steel;

• aluminium;

• copper;

• stainless steel;

• cast iron;

• or nickel.

The most well-known cold weld formula is provided by JB Weld. However, a number of other manufacturers have come up with similar products boasting highly advanced formulas. These products have usually been designed for specific applications.

The most common products on the market are liquid epoxy resins, but it is also possible to find metal epoxy putties that come as two pastes that need to be warmed up slightly before being mixed together. These epoxy putties contain a mixture of liquid resins and a purified metal powder to match the type of metal you are hoping to bond.

It's important to be aware that the chemical reaction that occurs when the two parts of epoxy adhesives are mixed happens very quickly. With this in mind, it's best to prepare only the amount you need for your repairs as any leftover mixture will have to be thrown away.

A spatula, decorating knife, cloth, file, sander and sandpaper are all you need to bond metals with an epoxy adhesive. The types of finishing tools required (such as files, a sander and sandpaper) depend on the type of repair you are carrying out and how neat you want the finish to be.

Rubber gloves should always be worn when handling an epoxy adhesive.

How to apply a metal epoxy adhesive

1. Clean your surface with a degreaser then use sandpaper to rub down the parts you want to assemble.

2. Use a spreading tool to spread the epoxy adhesive on in a thick layer before wiping with a cloth to remove excess product.

3. Once the product has cured, you can file or sand down the area for a neat finish.

4. It is possible to paint over the repairs if necessary.

Please note that if you are dealing with a leak, you must, of course, turn off the water supply before you start work.

Bear in mind that a cold weld compound will work perfectly well for minor repairs that are not subject to stress loads. Nevertheless, it will never be a long-term alternative to gas welding, brazing or arc welding.

It's also important to think of the finish of the repairs especially if you are repairing decorative elements or exposed pipes.

In no circumstances should this type of product be used to repair tools or lifting equipment unless the item is serviced by an approved repair/service agent.

For example, if a serious accident occurs after using a repaired jack that doesn't have a certificate, you will no doubt run into big problems with your insurance provider even if the repairs were carried out by a qualified welder. In this case, it's best to simply scrap the tool or destroy it so no one can attempt to use it in future.

Generally speaking, this type of product can never be used to repair any item that is subject to tensile stress unless there is minimal risk in case of potential bond failures.