Before you decide to glue metal, you should consider soldering first. It will provide a firmer, more stable hold for attaching metal pieces. However, if you have no experience or access to the appropriate equipment, follow these steps to successfully glue metal to metal instead.
Step 1 - Choose Your Glue
There are several kinds of special adhesives on the market for this purpose, including epoxy, polyurethane, and cyanoacrylate products. Two of the best choices are super glue and two-part epoxy. Two-part epoxy comes separated into two components which must be combined before use. This type is more involved than using super glue, but it creates the strongest metal-to-metal bond. Either glue can be purchased at a local hardware or craft store.
Step 2 - Clean
To begin, get rid of any debris on the surfaces by cleaning and sanding thoroughly. Also, take care not to touch the bonding surface with your bare hands, as the oils from your skin will sit on the surface and interfere with the glue. Sand the two surfaces with a fine-grit sandpaper to add texture, as doing so makes it easier for the pieces to form a bond.
Step 3 - Apply Glue
You may then apply the glue to the surface. Make sure to follow the instructions on the packaging so you do not use too much or too little glue. If you choose to use epoxy, the directions will require that the two components (adhesive and hardener) be mixed before you bond the metal surfaces. Apply the epoxy within a couple minutes of mixing or you risk ruining the bond, and then give it at least 24 hours to cure completely.
Super glue offers a more instant bond, but it is best used when the metal surfaces fit closely together without gaps, as extra space can interfere with how secure your bond is. Usually, the initial bond is made after about a minute, but it is best to let the super glue sit overnight.
When working with glue, be careful not to spill any on yourself or other materials in your work area, and always make sure your space is well-ventilated, as these products can emit hazardous fumes. For extra safety, wear a respirator or face mask and safety glasses.
Step 4 - Clamp
It is recommended you clamp the two pieces together or find another way to apply pressure after gluing. You will get a stronger bond this way because most high strength glues go through a chemical curing process before they are completely secure. Follow the drying times on the glue's packaging so the two pieces are given the appropriate amount of time to form a bond.