welding cast iron to mild steel
Welding cast iron to mild steel is for the most part done with ornamental iron such as gates and fences. the ornaments are typicaly cast iron such as spearpoints and fit over the top of what ever square tubing size ect you are working with. If you weld say with a mig welder in the normal mannor you rweld will cold roll and ball on you leaving a poor appearance that you will have to spend time grinding to make look good. Fortunatly it is not a matter of strenght or how much penetration ect. It is just ornamentation but must look good. Now take your mig welder with say 035 wire and use pure argon..(less spatter). Turn your welders heat up somewhat past what your normanl setting would be for what ever thickness you are using. Use breif spot welding like techniques overlapping as needed. You will find that this makes a good wash bead with no undercut or cold roll. The argon gas helps to keep down all the extra spatter welding cast iron to mild steel seems to cause. Larger peices such as caps for say 4by4 gate posts or fence posts, i preheat as uniformely as possibly to just under cherry red then weld as described.
It welds badly because cast iron is actualy dirty, literaly with particles of dirt in the cheap castings, wich the ornaments are. Not haviong the need to be anealed or nodular for instance. If the welds are not going to show then you dont have to do this. It will still weld, just do not expect the clean perfect welds you are used to. And NO I do not have PICS AND I dont own a digital camera nor do i know how to use one let alone put them on a computer.