Clean the wrought iron well. If the iron is new, it will be coated with a thin layer of oil to prevent rust from setting in before the iron is used. The oil must be removed prior to welding and painting. Alcohol and a lint-free cloth or rag makes short work of the cleaning process. Remember to only clean the iron you intend to use, because oxidation can occur in a matter of hours if left untreated.
Cut the wrought iron carefully. One of the most important things to consider when preparing to weld wrought iron is that it is cut correctly. Even the slightest angle on tubing that is meant to be completely straight and flush can throw things out of alignment. If you have access to a chop saw, it is recommended to cut the steel in bulk so that it all ends up at exactly the same length and with the same angles. If not, measure very carefully and cut precisely so that you achieve the desired outcome. Also, it is better to cut too long than too short, so always err with a long cut to be safe.
Set the welder. Inside the door of the welder there is a chart that will tell you how hot to set the welder for each thickness of metal. Use that as a start point, and then fine-tune if necessary once you begin welding. It is better to weld too cool than too hot, because if you burn through the wrought iron you can create a mess. Start cool and gradually turn up the heat for better penetration.
Place the ground clamp close to the work and weld the iron. The welder will produce the cleanest and strongest arcs if the ground clamp is placed near the weld. If the wrought iron project is a big one, it is okay to keep moving the clamp along with the welder to ensure quality work. Keep the tip of the MIG gun about a quarter-inch away from the surface of the wrought iron and move slowly for best penetration. It is a good idea to prime and paint the materials as soon as possible after welding to prevent rust.