What Kind Of Welding Rod To Use On Cast Iron?
A welding rod refers to an electrode (i.e. 6011 vs 6013 ) of a filler metal that is utilized to join two separate pieces of metals while welding. Welding rod is like a metal wire, and the materials are similar to the metal that is being welded. There are generally two types of welding rods –
- Consumable, and
- Non-consumable
The consumable rod is consumed during welding. The TIG (Tungsten Inert Gas) welding, the rods are usually non-consumable, and with the MIG welding, the rods fed the wire continuously.
Types of Cast Irons and Different Welding Processes
There are different welding processes that you can follow. However, before welding, it is a must to recognize the material or the types of cast iron. Different cast iron has different weldability, such as –
White iron: This cast iron is almost unweldable
Gray iron: This cast iron is very hard to weld, but it is the most common type of cast iron that is welded.
Ductile iron: This iron is rarely welded because it is quite expensive and a slow process.
Malleable iron: This iron can’t be welded because welding can change the properties of the metal.
After determining the welding material, it is time to select the welding process. Some of the welding processes are –
MIG welding:
MIG welding is a popular welding process as a beginner. It can be a good solution to repair cast irons. It is an arc welding process, where a solid wire electrode is used through a welding gun. This welding process can join two separate base materials together. MIG stands for metal inert gas.
TIG welding:
In this welding process, an arc is formed between the pointed tungsten electrode. The electrode isn’t consumed in this process. In addition, the welder doesn’t have to manage the heat because of the metal deposits from the melting rod.
Arc/Stick welding:
It is the best process for welding cast iron if you use the right welding rods. In this process, anyone can join two separate metal bodies together by using electricity. The electricity will create heat and melt the metal.
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How to Select a Good Welding Rod
Welding a cast iron is really painful because one wrong move can ruin the entire structure or can make the crack even bigger. Perfect welding can give your cast iron a new and fresh look with more internal strength. While looking for a good welding rod, it is better to check the following attributes –
Tensile strength
Presence of Graphite
Ductility
Base metal
Corrosion resistance
Weld position
Current
Polarity
It is recommended to take the welding rods that have graphite rich flux because graphite can bind the carbon in the cast iron chemically. Thus, it limits the migration into the welding metal. There are usually two popular types of cast iron welding rods –
Ferro-Nickel welding rod: This welding rod is cheap and contains 47% nickel and 53% steel.
Pure Nickel welding rod: Pure nickel contains 99% nickel. This rod is very expensive and is ideal for welding cast iron. Pure nickel can make the cast iron soft and more malleable.
What Kind of Welding Rods Should You Use on Cast Iron
Now, it is time to know about the rods that should be used on cast iron while welding –
Pure nickel rod (99% nickel): This is regarded as the best welding rod to use on cast iron. This welding rod can make the iron soft and machinable and can minimize cracking. However, this rod is very expensive, and that’s why welders often avoid using this rod.
45% iron and 55% nickel mix rod: This is affordable and appears similar to the cast iron after welding. It can produce a machinable weld, though it is harder compared to the pure nickel rod.
Iron rod: This rod is cheaper than the iron-nickel mixed rod, but it will produce different colors after welding. It is quite tough to use since it can shrink. It is not so machinable because it gets hard during welding.
Stainless steel rod: Using stainless steel welding rod can change the properties of your metal. This steel has the property to shrink or expand with temperature, which may result in developing cracks.
Brazing bronze rod: You can use this rod with the TIG welder. This welding rod can help you to achieve strong support in the crack or at the joint. It will neither change the properties of your cast iron nor cause cracks.
These are the five most common and comparatively better welding rod to use on cast iron. Besides, there are some other welding rods that contain copper-nickel or copper-zinc, but it is better to avoid these welding rods. You can learn more by visiting How To Weld Cast Iron With A Mig Welder
These are the most common questions that people ask –
#1. What is the best welding rod as a beginner?
As a beginner, it is better to use the most popular rods such as stainless steel.
#2. Do I need to remove oil or rust before welding?
It is better to clean the metal before welding because oil or rust can cause disturbance during welding.
#3. Can I pour cold water on just welded metal?
Pouring cold water on a just welded metal can cause fracture because the temperature of a welded metal is responsible for swelling or shrinking.
#4. Can I close my eyes while welding?
Closing both eyes isn’t a good option. You can shield your eyes during welding.
#5. Can the welding fumes hurt me?
You may feel uncomfortable in your eyes or nose if the fumes enter in your body. This is why, it is better to cover these organs while welding.
