What Kind of Welding Rod to Use on Cast Iron?

Are you keen to weld cast iron with a MIG welder? You’ve got to check out the right rod sure to give you excellent results. Without the right rod, your final weld could be underwhelming at best.

To know what kind of welding rod to use on cast iron, you need proper info. And for excellent info, stay glued to this piece!

Right here, we’ll be checking out the best welding rods perfect for joining cast iron pieces. Also, you’ll get relevant facts on other essential, related stuff to make your welds a lot better.

Types of Rods to Weld Cast Iron

Nickel Rods

Cast iron welds are easier to manage with a nickel-based rod. Your choice for a nickel-plated rod should focus on the result you hope to achieve. And here’s more info on nickel rods ideal for several purposes.

High-Level Nickel Alloy Rods

Most high nickel alloy rods come with 90 ~ 99% pure nickel. Also, many of these rods get complemented with steel or other durable metal.

While high-nickel rods tend to produce more durable results, it’s more likely they’ll go for a higher rate.

High-nickel alloy rods can get machined and performs excellently on low – high strength metals. These rods also join cast iron with minimal to intermediate phosphorus in their makeup.

Using a high nickel rod for furnace brazing could deliver excellent results, depending on how small your join is.

Mid-Level Nickel Alloy Rod

Mid-level nickel rods feature around 45 ~ 60% pure nickel. These rods come with a similar makeup to high-level options, with a slightly handier build.

With these rods, you can get wide workpieces a solid join. And since there’s a considerable amount of steel and other alloys in this rod, lesser cracks form post-weld.

More durable, machine-able welds can get completed with a mid-level nickel alloy rod. Also, these rods cost a lot less than its high-nickel option.

High Steel Alloy Rods

Steel electrodes are by a mile the cheapest rods for welding cast iron. Steel rods are perfect for getting fillings, and basic repairs rounded off.

A significant benefit of using high steel alloy rods is their agreeable nature to weld not-so-neat cast iron. So, if you’re planning on welding really old cast iron, steel alloys remain your best bet for exceptional results.

How Best to Weld Cast Iron

Pre-Heating Cast Iron

Using a blowtorch remains a comfortable way to get cast iron preheated. Ensure you get your cast iron heated to around 250 – 700ºC. The higher your heat treatment, the longer it’ll take your workpieces to cool.


Furnace heating is a top way to post-heat your welded cast iron. In some cases, welders could apply flexible metal filler across the joined piece for added adhesion and crack elimination. Other welders use a charcoal stove and place the newly-welded pieces in a bucket of sand.

Top Methods to Cast Iron Weld


Tungsten inert gas (TIG) is an excellent choice for joining cast iron pieces. TIG processes can get completed without pre- and post-heating, making it one of the top options out there.

But when you’re just starting, you’ve got to rely on heating your workpieces before and after welding.

The main reason why you’ve got to heat up your workpieces is to prop up carbon migration.

TIG on steel

Proper TIG welding cast iron to steel could be challenging for some newbies. But with the right settings on your welder and ideal cast iron, you can get proper joins set up.


Metal inert gas (GMAW or MIG) processes can get excellent cast iron welds. A lot of experienced welders will opt for steel, and durable nickel wire for a MIG cast iron weld.

When you’re selecting a nickel or steel rod, a high-argon gas will provide excellent results. Getting a quality shield on your cast iron piece promotes better merging potential. Although this weld could rust, later on, you’re likely to get long-term use from your joined pieces.


Stick (SMAW) welding is an excellent choice for newbies and experienced welders. Steel electrodes are ideal for numerous join operations, particularly dense pieces.

Also, some other metal electrodes with alloy mixes guarantee better machineability. And if you’re planning more challenging welds like overhead welding, arc welding is a great cast iron option.


Can you weld cast iron with 6011 rods?

6011 rods contain a considerable steel content and can weld cast iron without hassle. One reason why 6011 rods are ideal for cast iron is the merging potential they offer in both workpieces.

The mild steel clamps onto both workpieces, creating a sturdy weld.

What is the best way to weld cast iron?

Welding cast iron is best with pre/post-heating both workpieces, or without heating at all. Newbies and intermediate welders need both workpieces heated, while pros can manage a quality weld without any heat treatment.

Preheating stunts the cooling speed of your welds. On the flip side, pre/post-heating the entire workpieces results in more balanced welds.

Can cast iron be welded with 7018?

7018 is a mild steel electrode and can get cast iron properly welded. But using 7018 to weld cast iron makes peening, preheating, and cooling tricky to manage.

But the final results using a 7018 electrode could be great if you stick to a detailed preheating/post-heating regime.

Is brazing as strong as welding?

Brazing offers durable joins and assures exceptional longevity. But when you consider long-term use and intended placement, brazed joints may weaken easily.

Welded joints provide stronger bonds at high temperatures and assure more resistance to cracks and pressure.

Can Cast Iron be glued?

Polyurethane adhesive is excellent for joining cast iron.

On the flip side, if the cast iron fitting functions under high-pressure conditions, getting a weld should be better. But if you’re planning to use glue, you could also get steel-reinforced epoxy is a great choice.

Final Word

With this info, what kind of welding rod to use on cast iron is sure to be natural to pick. Getting excellent welds for your cast iron becomes a lot easier to manage.

Regardless of your skillset, you’re sure to get cast iron pieces joined without hassle, and achieve better than ever results!