Experienced welders know that different welding rods (electrodes) are best-suited to various kinds of welding. When it comes to choosing electrodes for welding cast iron, there are typically three factors you’ll want to consider: cost, machine ability, and if the weld requires multiple or single pass.
One of the issues with welding cast iron is that, due to its stiffness and the possibility of cracking, the trend is towards steel. However, cast iron is an equal friend to welders who know how to work with it.
What You Need to Know
When you’re welding cast iron, it’s essential to choose a rod that is designed specifically for this material in order to avoid improper fusion (like fusion line cracks). Basically, what you need to find are electrodes and wires that are soft, machinable, and equipped with a high percentage of metals like nickel or copper.
If the amount of the metal in the electrodes is satiable, then you will get exactly what you need – strong welds that can tolerate the phosphorus remainder that’s a result of the casting process.
So, I will show you my favorite welding rods for cast iron to help you make a choice yourself. My top picks range in price, so you’ll be able to find an option that’s suitable for your budget. I will highlight their features, pros, and cons. Make sure you consult the buying guide at the end of the article, to get an idea of how to choose an electrode that will give you a perfect weld deposit.
Top Cast Iron Electrodes
1. Best for Professionals: Lincoln Electric 1/ 8” 7018 MR Welding Rods
Lincoln Electric 7018 is among the most common electrodes used in the welding niche for cast iron. I especially recommend it for professionals as it’s perfect for structural steel welding, repair work, and heavy pipe welding.
Because of its low hydrogen content, the rod can be sensitive to exposure. The Lincoln 7018 should be exposed to air only for a limited time in critical applications before it becomes defective. If your job requires welding inspection, I would recommend that you keep it in a rod oven until you need to use it, so you can preserve both the rods and their flux.
On the other hand, in simple, non-critical applications, this model can stand exposure for some time before it’s compromised.
The Lincoln 7018 electrodes are moisture-resistant and hard to decompose, which makes them practical for various stick welding jobs.
This option calls for some care in handling, which can get a bit bothersome at times. If you opt for this welding rod, remember to keep it away from humidity and wait to open the rods when you are finally ready to burn them. They are hermetically conserved, so once you open them, the process of decomposition will begin.
- Great choice for stick welding jobs
- Good for repair work
- Convenient for structural steel and heavy pipe welding
- Hermetically sealed package
- Can’t leave it at room temperature for long
- Needs to be kept in a rod oven before usage
2. Best for Beginners: Hobart 1/ 8” 7018 Welding Rods
Another great welding rod for cast iron, the Hobart 1/ 8” 7018 is a low-hydrogen electrode that can be used in all positions. It’s also suitable for low, medium, and high-carbon steels.
The Hobart welding rod is a great option for someone who is a beginner, as they are quite affordable and burn really efficiently. Although they don’t have the premium properties of some of our other recommendations, they’re a solid place to start. Hobart 1/ 8” 7018 has 70, 000 TSI tensile strength.
Overall, these rods are quite durable. The rod tubes prevent moisture and provide a safe environment.
However, these rods are not recommended for low-voltage AC welders. Another potential drawback is the fact that their packaging is plastic and it’s not hermetically sealed.
- Suitable for any welding technique (in all positions)
- Convenient for beginners
- Plastic packaging
- Not hermetically sealed
- Creates slag that’s hard to remove
3. Best for Dirty Surfaces: Forney 1/ 8” 6010 Welding Rods
The Forney 6010 is an all-position welding rod that (like all the other 6010 electrodes) can weld through almost any kind of contaminant, including grease, oil, rust, and mill scale. What welders especially like in Forney 1/ 8” 6010 is that you can get the job done even if you don’t clean or grind the material beforehand.
You’ll love how versatile the Forney welding rods are. You can use them for professional tasks and repair work that can often get messy. The dig of this welding rod is quite a bit deeper than the low hydrogen type, which allows it to penetrate through contaminated metals. The Forneys are also excellent for welding vertically downhill and uphill. You can get the best weld when working from top to bottom.
These electrodes are also a good choice for professional welders, as they’re commonly used to make the root pass weld on pipe joints.
I would especially recommend this welding rod for fabrication projects, stick welding, and rig welding in general.
- An all-position rod
- Great for stick or rig welders
- Penetrates easily through contaminated metals
- The flux coating can at time extinguish the arc
4. Best for AC Machines: Hobart 1/ 8” 6011 Welding Rods
When it comes to the potential of welding rods, you can consider the 6011 models as a close relative to the 6010s. Hobart 1/ 8” is excellent for working with AC machines, but it also works efficiently with thinner metals and sheet metal, as it doesn’t cause a lot of warping.
If you have an entry-level AC stick welder, this model is, in fact, an all-purpose rod that you should consider a must-have as it contains a special coating that keeps the arc ignited and can provide deeper penetration of plate metals.
- Great for working with AC machines
- Works efficiently with thin metals
- Low warping
- Low-quality plastic packaging
5. Best for Strong Welds: Hobart 1/ 8” 6013 Welding Rods
I especially recommend this rod if you are dealing with fabricating projects that require a lot of strength. Although the welds are not always necessarily good-looking, the composition of this rod will help you achieve a strong weld.
The Hobart 6013 welding rod can be used on multiple polarities, including DC+, DC -, and AC. Quite similar to the 6010 and 6011, the Hobart 1/ 8” 6013 can easily penetrate through rust, oil, galvanized coatings, and mill scale.
You’ll find that the Hobart welding rods are designed for work in different positions. The arc process of the rods is quite smooth, making them convenient to weld metal in irregular positions.
- Great for multiple polarities
- Solid penetration through contaminated surface
- Excellent for strength-demanding projects
- Relatively smooth arc
- Can weld metal in irregular positions
- May produce a lot of splatter in the weld area
Best Rods for Welding Cast Iron: Buyer’s Guide
Finding the right electrode for cast iron might be a bit confusing. However, if you know what the specifics of your work are and learn a bit more about what rods are suitable for cast irons, you will have no problem choosing the right option for you.
The Right Type of Metal
First, you need to make sure that the cast iron you’re using is indeed weldable, depending on the graphite form (it can appear as graphite flakes, rosettes, in nodular or spheroidal form, etc.). Usually, cast iron has a carbon content between 2% and 4%, about 10 times more than steel. This is generally why cast iron parts have graphite flakes, and they’re responsible for the grey color inside the weld cracks. You can get more information about how to weld cast iron and what methods to use.
The rod that works best with cast iron is soft, machinable, and contains high levels of metals like copper or nickel, which can stand the phosphorus that is produced during the welding process of cast irons.
The 99% nickel-based electrodes produce machinable welds that are the best option for casting with low to medium phosphorous contents. A more economical option are the 55% nickel rods that are mainly used for repairing thick sections. The third option are the steel rods that are most convenient for simple repairs and fillers. These are also quite user-friendly for arc welding as they can tolerate contaminated castings.
What Methods to Use
In fact, arc welding is a great, versatile method for welding cast iron in order to melt steel. The rod will melt the base steel so the cast iron can flow through it, placing base steel through the weld. MIG is the second-best of the welding processes that we’d recommend for iron, though it’s a bit less versatile than MMA (arc).
Another type you can try for cast iron is TIG welding. It can help you connect pieces of cast iron, but you have to be careful in the process – it’s easy to mess up.
You can also try gas welding (more specifically Oxy-acetylene fusion) for cast irons. It’s machinable, you’ll get a decent color match, and it cools slowly. On the downside, the high heat can cause distortion in the iron.
If you opt for working with cast iron, search for a rod that has properties specific to cast iron, so it will decrease the chance of anything going wrong in the casting process. If you are a newbie, make sure to choose something affordable that you can practice on while developing your skills.
Hopefully, my favorite welding rods for cast iron and quick buying have been helpful in your search for the right electrode for your welding work. You can search for more posts and guides about welding methods on our website.
Frequently Asked Questions
What is the best way to weld cast iron?
The best way to weld iron is with arc, MIG, or TIG welders. Of course, you also need to ensure the proper use of a suitable rod.
Can you weld cast iron with low hydrogen rods?
Yes – it’s best to weld cast iron through MMA by using low carbon steel and low hydrogen electrodes at low currents.
What are the main fillers for welding cast iron with a stick welder?
The main filler types that work well for cast iron stick welding are cast iron-covered electrodes, copper alloy electrodes, and nickel alloy electrodes.