Welding on cast iron is a little different from the weld metal on the other. Because the chemical makeup, cast iron is prone to cracking when heat is applied. Metals such as wrought iron or mild steel can be welded with only minimal preparation. However, cast iron welding requires a material that has become hot before the bow struck, and also require a slower cooling time. If done properly, cast iron can be repaired very successfully.
Instructions
Heat a cast iron evenly with a torch. Because of its nature, cast iron will crack when welded as cold. It requires pre-heating the material to avoid damage. Apply using a torch to heat the entire surface of cast iron, including parts to be welded. By bringing the temperature of cast iron that slowly before welding on it, we can ensure that the heat resulting from the arc does not damage the metal itself. If the object is very large cast iron, heat the surrounding area as the area to be welded as possible. If small pieces, simply reheat the whole thing.
Welding cast iron is very slow, stopping every 1 to 2 inches so that the iron to cool a little in between welds. If you try to weld the whole area in one shot, iron is likely to crack due to extreme heat stress produces. If you are using flux cored wire, use a wire brush and scrape the flux off the weld every time you pause to make sure that gets arc welder, good clean when you resume welding.
Cast iron cools down very slowly after welding. If cast iron is allowed to cool too quickly, cracks are inevitable. If an item is welded rather small, you might consider wrapping it in a thermal blanket or even buried in the sand to prevent rapid cooling. If a large item, hit it with a torch every thirty seconds or so for a short time, which will bring the temperature down gradually.
Welding cast iron is very slow, stopping every 1 to 2 inches so that the iron to cool a little in between welds. If you try to weld the whole area in one shot, iron is likely to crack due to extreme heat stress produces. If you are using flux cored wire, use a wire brush and scrape the flux off the weld every time you pause to make sure that gets arc welder, good clean when you resume welding.
Cast iron cools down very slowly after welding. If cast iron is allowed to cool too quickly, cracks are inevitable. If an item is welded rather small, you might consider wrapping it in a thermal blanket or even buried in the sand to prevent rapid cooling. If a large item, hit it with a torch every thirty seconds or so for a short time, which will bring the temperature down gradually.
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