I’ve been asked on several occasions how to weld cast iron with a stick welder. Stick welding has been around for many years – more time than I have been in the trade.
It is one of the few trades that have a lot of history behind it. Some say back to caveman days when they would lay down hot rocks and melt them into pieces of metal on top of other metal to create notches and holes.
You can weld cast iron with a stick welder! I’ve included instructions on how to weld cast iron with a stick welder. I have even included a step-by-step guide for welding cast iron with a stick welder. You can learn all the tips and tricks.
I have acquired years of practicing different methods and techniques. If you’ve always wanted to learn how to weld cast iron or just want to learn more, this is the site for you!
What is Stick Welding?
Stick welding, or manual welding, is one of the traditional methods for joining metal parts together. The most common type of stick welder is called a manual metal arc welder (MMA).
Using an arc as a heat source, the base material is melted and joined to the filler metal. In other words, it melts and fuses the materials together without sending them through a tube.
Stick welding involves less set-up time than other methods and produces less spatter due to its easy use with direct contact with the workpiece. It does not produce fumes or fumes that are dangerous if the sticks are used in a proper manner.
Stick welding provides multiple flame styles such as short arc, long arc, open circuit, and dipping flux core & gas shielded to provide superior strength/tensile strength/ductility as well as proper weld penetration & flow characteristics.
Can you Stick Weld Cast Iron?
Stick welding is a good way to weld cast iron because it works well on both ferrous and non-ferrous metals. The process involves using a filler rod in order to fill in gaps between materials being joined together during welding, which makes it ideal for use on cast iron.
Cast iron is a composite material that consists of a mixture of iron, carbon, and silicon. The silicon increases the strength of cast iron by allowing for the formation of an intermetallic compound with iron and carbon.
This can be useful for welders because it ensures that the weld will remain strong and not crack under pressure or stress.
Stick welding can also be used to create joints between two pieces of cast iron without requiring heat treatment afterward (as would be needed if arc welding were used instead).
The above information is described precisely, so if you want to know step by step for further information, keep reading!
Also See: How to TIG Weld Cast Iron: With and Without Preheating
How to Weld Cast Iron with a Stick Welder? Step by Step (Ultimate Guide)
1. Recognize the Alloy of Cast Iron
Cast iron is the most commonly used and welded of all ferrous materials. From auto engines and transmissions to castings for appliances and other domestic items, cast iron is everywhere. If you are looking for a guide on how to weld cast iron through a stick welder, then this is it.
Cast iron is either gray, nodular or malleable. The alloy should be written on the packaging. If it’s not, call the manufacturer. Your stick welder has an automatic hookup (setter) that will do different things depending on what alloy your iron is.
Spark Test
A spark test is an excellent way to find out what sort of metal you are working with. All you need is a metal sample, which can be easily obtained by cutting off a small piece from an object.
When you strike the sample with a hammer, and one or two sparks fly out of the strike point, then your sample is iron.
If it is copper, silver, gold, or brass, then the sample will melt and flow into a blob at the strike point, but if it doesn’t do this and only produces a few sparks, then the material is either nickel or cobalt.
Identify the cast iron alloy. You can distinguish gray iron from ductile irons by testing their hardness:
3/2 PH, AISI 1018 is a gray iron that’s only slightly harder than ductile irons and much more brittle. If you hit it, expect to chip off pieces of your workpiece instead of making nice welds with it.
Ductile irons will be tougher than gray iron but still weaker than carbon steel; if you hit one of these alloys with a hammer, it will bend or dent before breaking.
2. The material you Need to Weld.
To do any welding work, you need to have all the necessary personal protective equipment. This includes:
| No. | Material Needed |
| 1 | A welder helmet |
| 2 | Face shield |
| 3 | Leather gloves for protecting your hands |
| 4 | Leather boots to protect your feet |
| 5 | Shop jacket |
| 6 | Suitable clothes for welding |
| 7 | Welding respirator |
Safety equipment is crucial for preventing injuries in the workplace because it can reduce the chances of being injured from exposure to toxic fumes and possible burns. So don’t cut corners when you make your purchase!
Now, you have to assemble all the welding tools:
- You’ll need a hammer and chisel to remove any large pieces of scale, rust, or other impurities.
- A wire brush cleans off the surface of the casting, removing dirt, dust, and other foreign particles.
- An angle grinder with a thin abrasive disk to smooth out rough welds and hand files to get into tight spots.
- An oven or a flame torch.
- Two welding electrodes.
- Two welding cables.
- Temperature sticks or an IR thermometer.
- A drill for the purpose of crack repairing.
- A small ball-peen hammer is a final tool you will need to give your beads a finished look.
3. Suitable Rod for Stick Weld Cast Iron
ENiFe-CI is a high-quality, low hydrogen, and rust-resistant welding rod. It offers good weld penetration and better arc performance in cast iron than most other brands of ER70S-6.
The ENi-CI is a great choice for stick welding cast iron, but it can be expensive depending on the size of the rod you’re using. The cost goes up as you increase in length, like any other welding rod.
If you need to get rid of rust and patch small holes without having to do alot of prep work on your cast iron, an ESt rod will work well and is cheap.
Stick welding cast iron with direct current is possible but difficult. However, if you use the right rod, you can make good welds in cast iron. I recommend using an electrode designed specifically for stick welding cast iron.
The most important advantage of a specialty rod vs. other electrode types is how far it penetrates the metal while the arc is active.
The special metals used in these electrodes allow them to absorb heat at a higher rate than other types of weld rods, and this helps welders compensate for the thermal effects of welding on surrounding materials or utilities.
A clean, deep weld requires a rod size that won’t overload the electrode with too much heat. In most cases, you can successfully weld cast iron with a 4/0-5/0 diameter ground electrode wire.
If you are welding thick material or use a thicker electrode, you may have to increase the wire diameter while keeping the current constant.
If you have too much amperage going through your stick welder and rods, it will overheat and cause porosity in your weld beads.
4. Right Amperage for Stick Weld Cast Iron
If you want to weld cast iron with a stick welder, you need to know what rod and amp setting to use.
Knowing how to select the right one is crucial because using more amperage will cause the rod to run too hot and make it brittle, while using too little can result in incomplete fusion or poor metallurgy.
A low amperage setting for stick welding cast iron means that the puddle will be hard to control and fill the edges and cones too much. Therefore, if you are also planning to weld cast iron with a stick welder, make sure that you are using enough wattage.
Stick welding cast iron with a DC+ polarity creates smoother welds because I experienced this, prevents too much heat from entering the work area, and produces less spatter. Start the repair by setting your stick welder to the appropriate current.
The amount of amperage you use will depend on what type of rod you are using, but it is usually between 80 and 120 amps.
Fortunately, you can use a variety of rods that work well with AC current to weld cast iron when using alternating current (AC) and straight polarity.
5. Surface Cleaning
It is always best to clean the surface of the cast iron before welding. Cast iron has impurities that are hard to remove, even after polishing or grinding.
You don’t want your good polishing job ruined by weld spatter, so be sure to clean every nook and cranny with a wire brush, grinder, sandpaper, or whatever else you’ve got lying around. Just don’t forget to remove all of that rust!
The biggest problem with cast iron is that it can absorb oil and other contaminants from the atmosphere, especially when it’s newly cast.
This will affect how your weld performs. In addition, cast iron may contain a large number of gases and water, which will affect its soundness. So before welding cast iron, it’s best to clean it by pouring boiling water over the surface.
If the metal you are working with has been cleaned of oils, waxes, and other contaminants, you will find that the acetone works well on its own. If not, then I suggest you use a combination of acetone and brake cleaner as your best bet.
6. Detach Broken/Cracks from Casting
For the best weld on cast iron, begin by chiseling out the crack and cutting lines parallel to both sides of the crack. This allows for a uniform weld to penetrate through the cracks and fill them in.
First, use an angle grinder to take off all of the rust and corrosion that has built up on your casting. Be sure not to get too close to the surface of the metal, or you’ll end up with a messy-looking weld.
Next, use a die grinder with carbide burrs to remove any remaining rust or corrosion from inside your casting. This will help ensure that there’s no debris left behind when you start welding.
Criteria of Detaching Cracks
To repair a crack, use adhesion to make the joint stronger than its original state. File the ends smooth and round them off with your hammer. Then you can use the tip of your electrode to draw in filler metal, working it into the cracks. You may need to add additional layers of metal over this to give it strength.
Criteria of Detaching Broken Parts from the Casting
Broken cast iron is a common problem for many people in their daily lives. Without the proper tools, fixing this can be a burden on your wallet and time. Fortunately, with a stick welder, I guarantee you that repairing a broken cast iron is quick and simple.
If you have a cracked or broken piece, you can fix it using a stick welder. This process requires a lot of time on your end, but the results are worth it!
Prepare the casting by scoring and breaking it in two where needed. You can also make two V grooves or create bevels for welding as needed.
7. To Avoid Fast Expansion, Preheat Casting
Preheating is a very important step in welding cast iron because it prevents cracks that result from thermal shock. It also allows you to do the soldering without having to worry about temperature differences between the material and the workpiece.
Heat the thicker parts of the casting with a flame torch. This will keep your welds looking neat and clean. And then, check the surface temperature again with a temperature stick to ensure you have consistent heat throughout the section being welded.
Preheat cast iron for welding by placing it on a heat source until the metal turns yellow. This will reduce the weld and make it stronger.
8. Avoid Long Beads for Stable Temperature
Cast iron is a tough material to weld, but it can be done with a stick welder. When you tack weld on cast iron, you should use short beads because this will prevent uneven heating of the metal.
When you are welding, it is important to use a stick electrode that has a higher carbon content than alloy steel. The carbon in the electrode helps create a high enough temperature to melt and fuse the metal without causing excessive spatter or porosity.
The moment you start welding, that heat goes into the metal and can cause the cast iron to crack or even spill. Prevent this by taking short beads on a large area instead of concentrating on one spot.
This way, your weld will be distributed evenly over a surface area large enough to absorb it without uneven heating.
9. Rescue the Welding Surface from Shrinking
Before trying to weld a cast iron with a stick welder, you must learn how to prepare it. Beads need to be peened, which means tapping all over the red hot forged metal after it is cast with a small rounded hammer. Peening prevents shrinkage stress that may crack your weld seam.
Cast iron has a high density and hardness rating, which makes it difficult to weld by stick welding.
Further, cast irons are usually found in heavy sections, which limits penetration into the metal. In order to overcome these challenges, I advise you must use minimal heat input into the metal and correct preheat methods.
10. Reheat if Needed
If you have cast iron work, the first thing you should do is make sure that the casting has been fully preheated. It is also important to reheat its temperature during welding because it will reduce heat loss during the welding process and prevent cold cracks from forming in the casting.
11. It’s Time to Cool Down the Surface with Care
Keep your hands and sparks off the cast iron during cooling. Protect the casting with a thick blanket or damp cloth so it can cool down slowly.
If you don’t insulate the entire casting, it will cool off unevenly, and one side could be harder than the other, which would make it very difficult to weld correctly.
A good way to do this is to wrap it in blankets and leave it on a flat surface until it reaches room temperature and you can touch it.
How to Stick Weld Cast Iron Without Preheating?
Cast iron is notoriously difficult to weld. It’s a heavy metal, and the surface oxidizes easily. The oxidation makes it harder to work with, and it can even make your welds look like they’re falling apart!
Stick welding cast iron is one of the most challenging jobs in welding. But it doesn’t have to be that hard. Here are some tips that I will discuss in the following for how to stick weld cast iron without preheating:
- Use a good tip, such as an E7018 or E6011 rod, and make sure your rod angle is at 90° or below. If you’re using an 18-gauge wire feeder and a 5/64″ diameter electrode, this means using a 0° tip (which will create a ball arc).
- Make sure your contact tip is clean, free of oil and flux residue—and don’t use any! You want the barest minimum amount of material on the contact tip so that there’s no chance of anything interfering with the arc itself when you start welding.
- Set up your machine so that it’s capable of producing a narrow bead profile (like 1/16″ wide or less) with high current settings that produce sparks as small as possible.
- First, make sure you’re using the right equipment. You’ll need a stick welder, which can be purchased at any hardware store or welding supply store for about $200.
- You’ll also need some flux core wire and an oxygen-acetylene torch. The torch should cost between $150 and $350. It’s optional, but it will help you get a better bead of weld!
- Next, you’ll want to make sure that the metal is clean and free of rust before you start welding. This can be done with an abrasive blasting machine or by simply scrubbing it with soap and water.
- Next, place your metal together so that the parts touch each other as closely as possible without overlapping.
- Then place your electrode against the edge of one part of the metal (it doesn’t matter which one).
- Now press firmly on the trigger until you hear a “click” sound from your welder; this means it’s ready for use!
- Once you’ve pressed firmly enough on the trigger to turn on the welder, drag it across both pieces of metal until they’re fused together by molten metal from within their depths; this will create a stronger bond than just.
Welding Cast Iron with Nickel Rod
Welding cast iron with nickel rods is a great way to create strong, durable joints in your welding project.
The process is very simple, but it’s also important to follow the instructions carefully and use the right equipment.
| Steps | Description |
| Step 1 | First, you’ll need to clean your pieces by sanding them down with sandpaper so that they’re completely free of grease and oil. |
| Step 2 | Then, you’ll want to preheat them in an oven at 350 degrees Fahrenheit for 15 minutes before you begin welding. This helps ensure that they won’t crack during the heat-up process. |
| Step 3 | Next, you’ll want to mark where you want the joint to be on each piece of metal and then place them together so that they overlap slightly. This will help keep them from shifting as you weld them together. |
| Step 4 | Once everything is lined up correctly, take your nickel rod and press it into place with a hammer. You should see sparks fly as it melts into both pieces of metal! |
| Step 5 | Once everything has cooled down, remove any excess nickel from around your joint using an angle grinder with a wire brush attachment so that there aren’t any sharp edges left behind; this will help prevent any future rusting problems from occurring over time. |
Limitations of Stick Weld Cast Iron
When it comes to the limitations of Stick Weld Cast Iron, there are a few things you should know.
| No. | Subtitle | Description |
| 1 | Not Smooth | The welds that stick weld cast iron can make is not quite as smooth as those made with other welding techniques, and they have a tendency to crack when exposed to extreme temperatures. |
| 2 | Not Recommended | Stick welding cast iron is not recommended for high-stress applications because it does not have high tensile strength. |
| 3 | Non-strong | Stick-welded cast iron is not as strong as other types of welded materials like steel or aluminum. |
| 4 | Non-ductile | It is not very ductile, so if you need to stretch it out to fit into a space, it will break. |
| 5 | Poor Tensile Strength | It has poor tensile strength, so it can’t take much force before it snaps or breaks. |
| 6 | Low Thermal Conductivity | It has low thermal conductivity, so if you use it for cooling down parts like water or oil pipes and pumps, the pipes will burn through quickly and cause a fire hazard. |
Benefits of Stick Weld Cast Iron
Stick weld cast iron is a high-temperature material that has excellent corrosion resistance, low thermal coefficient of expansion, and high tensile strength.
It is commonly used in many industries, including the construction industry, as a structural material.
I will mention some of the following benefits to sticking weld cast iron:
Excellent corrosion resistance:
The material has good resistance to most acids and alkalis, as well as anodic reactions with oxygen and halogens.
Stick-weld cast iron can be used at temperatures up to 1,200 degrees Celsius for long periods of time without dissolving in water or corroding in salt solutions.
Low thermal coefficient of expansion:
The thermal coefficient of expansion (TCE) of stick welded cast iron is less than one percent per degree Celsius, which means it expands only slightly when heated or cooled compared to other metals such as steel and aluminum.
This reduces stress on joints during thermal changes and makes it easier to work with during fabrication processes like welding or to cut into different shapes for custom applications like building structures.
High tensile strength:
The tensile strength of stick welded cast iron (ASTM A48) can reach up to 900 MPa (megapascals), which is almost double that of mild steel.
Precautions During Weld Cast Iron with Stick Weld
Cast iron is a very hard, brittle material that is prone to cracking when heated. When welding cast iron with stick welding, be sure to take precautions to avoid cracking and other damage.
Cast iron is subject to thermal stress during welding. The thermal stress can cause cracking when the weld cools down.
To prevent this, I recommend that you use a high-quality filler rod that melts at a lower temperature than the parent metal. This will help prevent thermal stress and crack formation in your weld.
When welding cast iron with stick welding, you should also ensure that the surface of your workpiece is free from oil or grease. These substances can cause oxidation during the heat-up process and interfere with your weld bead formation.
Always wear protective gear, and make sure to clean your work area before you begin. Make sure you have a solid surface on which to weld, or else the hot metal can burn your table or floor.
Final Verdict!
So that’s the full-fledged guideline on how to weld cast iron with a stick welder. It’s really not too difficult. It just depends on the level of work you’re willing to put in. But little by little, you’ll start to see some great results.
In fact, the finished product might actually surprise you in terms of how good it actually looks. Plus, anything created by hand is always special to those who use and appreciate it. Good luck with your welding project!
FAQs:
What kind of welding do you use on cast iron?
There is only one kind of welding for cast iron, and that’s shielded metal arc welding (SMAW). You can also spot weld cast iron using SMAW.
Can u weld cast iron with 7018?
7018 is a great low-hydrogen electrode perfect for welding cast iron. It has a high resistance to slag, which makes it easy to identify possible porosity in your weld.
How hot should cast iron to be before welding?
Cast iron is one of the few materials that melt around 400 to 1100°F. Because of this, there are not many ways to prevent other sections from melting if welding at this temperature. The easiest way is to use cast iron with low-carbon steel, which melts at lower temperatures than pure iron.
What is the best rod to weld cast iron?
It’s important to use the right rod for your application as it will affect how well and easily you can weld. Nickel-based rods are ideal if you need to weld cast iron since they have the highest resistance to oxidation. But these rods also contain hazardous fumes, so make sure you get proper training before using them!
