Solder is a metal alloy that contains no iron. It can be purchased in sheet, wire, chip or paste form. Soldering takes place by joining two or more pieces of metal together using a metal alloy whose melting temperature is lower than the metals being joined. Wrought iron can be difficult to solder and soldering wrought iron is usually limited to making small surface repairs or sealing any gas and liquid leaks.
Tin the tip of your soldering iron, especially if you are using it for the first time. Heat it up and apply a thin coat of solder along the tip. This maintains a proper balance of oxidation and heating.
Clean any dirt and debris off the wrought iron using a wet sponge. Also clean the tip of the soldering iron with the sponge and saturate it with cold water, to the point of dripping. Quickly draw the tip of the soldering iron through the sponge just before making the joint, to prevent oxidation. Prep the surface of the wrought iron after everything is cleaned by coating the area with a thin layer of solder. This process is called "tinning."
Secure the wrought iron in a soldering stand so it won't move during soldering. Making a sudden movement while soldering can cause crystallization.
Heat the soldering iron. Apply a tiny amount of solder to the tip of the iron and push against the piece of solder with a half-pound of force. This will ensure an efficient heat transfer to solder. Do not hold the iron to the solder for too long; too much heat can damage the wrought iron. Apply the iron to the solder quickly with enough pressure to melt it but not overheat it.
Lay the heated piece of solder against the area of wrought iron you are repairing. Do not touch the wrought iron with the soldering iron. If the solder is not melting, than it is not hot enough. Quickly slide the solder into the joint between two wrought iron pieces, or over any area that needs repair. Be careful to not shake or bump the joint you create, because this can cause it to crack over time.
Place the soldering iron back on its stand without removing the solder until the iron cools. This will protect the tip from oxidation.