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EVERYTHING YOU NEED TO KNOW ABOUT THE E7018 WELDING RODS

The E7018 electrode is one of the most popular welding rods out there. It is one of the best electrodes for industrial uses and can even be used by beginners. But there is a lot to know about how to correctly use the electrode. No matter how easy to use it is, there are a lot of complications associated with it. I have compiled a full guide about everything there is to know about the 7018 electrodes, and I hope it helps you out.

The E7018 has a tensile strength of 70,000psi and can be used in almost all positions. It works on AC and DC+ polarity while also being a fill-freeze, medium penetration rod. Because of low hydrogen iron powder coating, you will have to be very careful storing 7018 electrodes not to ruin them.

e7018 in use

CHARACTERISTICS OF THE E7018 ELECTRODE

First things first, the 7018 electrode is considered to be one of the most versatile electrodes out there and it works best on low and medium carbon steels. The electrode also has a very low hydrogen content in its flux coating which means that the weld puddle gets very little amounts of hydrogen. (Excess hydrogen in the weld can lead to brittleness, delayed cracking, or hydrogen-induced cracking.)

The usability of this electrode is great, even beginners will have no problems operating it. The 7018 electrode also produces some aesthetically beautiful weld beads while also being structurally sound, it is a very good choice for working on buildings and pipelines. Even external welding is a good option because of its eye-pleasing beads.

The iron powder compounds present in the flux also protect the weld pool from contaminants such as moisture, hydrogen, and dirt while also increasing the deposition rate of the electrode. It is considered as a fill freeze’ electrode which translates to its versatility in terms of positions. But I would not recommend that you use it on a downward slope because of its thick and fluid slag.

The spatter formation is minimal, although the slag is a bit on the heavier side. The slag can be removed pretty easily, and is often self-peeling when the weld is done right.

WHAT DO THE NUMBERS ON THE ELECTRODE INDICATE?

The first thing which you should know about any electrode is what do the numbers represent. An electrode is not named after random numbers, each number represents a specific characteristic. One basic thing to keep in mind is that the letter ‘E’ simply denotes an electrode and nothing more.

  • The first two digits of the electrode represent the tensile strength that you can expect from the weld. In this case, the first two digits are ‘70’ which equates to about 70,000 psi tensile strength on the final weld. This high strength is one of the reasons why this electrode is preferred for industrial uses.
  • The third digit represents the positions in which you can use the electrode. In this case the ‘1’ means that the 7018 electrode can be used in all the positions but I would not recommend that you use it on a downward slope.
  • The last digit is a bit more complex, it denotes a lot of characteristics of the electrode including the flux coating, its penetration capacity and the polarity on which it should be used. The ‘8’ here means that the 7018 has a low hydrogen coating with a slight mixture of potassium and iron powder compounds.

You might also come across some types of the 7018 electrodes with some specific suffixes attached to them. For example, the 7018-1 equates to an increased toughness and ductility. While the ‘M’ indicates a military-grade electrode. Some other suffixes you might come across are the H4, H8, and H16 which indicate the diffusible hydrogen limits. The H4 would mean 4ml/100ml grams.

As a hobby welder, you don’t need to worry about these suffixes if you are going to be using the standard E7018 electrode. Most of the time, home users will never need a specific version of the electrode. Even in industrial applications, the standard version is used unless the job demands something different.

E7018 ELECTRODE SPECIFICATIONS

I have compiled the specifications of the 7018 electrodes discussed above in the following table:

Welding RodFlux compositionPolarityPenetrationTensile strengthWelding positionMotion Type
7018Iron powder low hydrogenAC, DC+Medium70,000psiAll but difficult to run vertical downDrag

MOST COMMON 7018 WELDING ROD USES

Because of the high tensile nature of the welds and their crack-resistant properties, the 7018 is most commonly used in industrial applications such as pipe welding, welding of pressure vessels, boilers, heavy equipment, ships, bridges, and manufacturing.

The 7018 also works pretty well on hard-to-weld metals which increases this electrode’s versatility.

Some of the hard-to-weld surfaces on which the 7018 electrodes can perform include surfaces such as simple low alloy steels, low-quality steels with a higher presence of sulfur. Surfaces that might face high levels of impacts over a long period of time, any weld that might face an impact at a low temperature, or joints with very complex designs.

HOW DO YOU USE THE 7018 ROD?

The 7018 is considered to be a drag electrode, meaning that it should be dragged along the surface while performing the weld.

There are a lot of finer points here to keep in mind.

One thing to keep in mind is that the 7018 has a high deposition rate, this means that the electrode will be depositing a lot of material during the welding stage. This is the reason why you should maintain a tight arc close to the welding joint. If the arc is loose or if it is too far away then the filler material will start going all over the place. This will give you a very weak and ugly-looking final weld.

The slag formation with 7018 is on the higher side, having a looser arc will worsen this situation.

As with all the stick welding electrodes, they tend to get shorter as the weld goes on. This is where you have to pay attention while maintaining the proper arc distance. My advice here would be to conduct a lot of practice rounds if you are a beginner. This is one of those factors which you will only master through ample practice. I would also suggest that you play around with different welding angles as well.

WELDING FILLET WELDS

Fillet welds are one of those techniques that look quite easy in the beginning, but the final welds often turn out to be very jagged and not aesthetically pleasing. One piece of advice here would be to keep the weld pool very close to the edge of the metal.

If you need to make multiple passes then you can try overlapping the passes over about 2/3 of the weld. Doing dry runs over an area which you will be welding will also make sure that your final weld looks clean.

REMOVING SLAG POST WELD

Even though the 7018 electrode is known for this aesthetically pleasing weld beads, it does leave quite a bit of slag. The slag can be very thick but the good news is that it is pretty easy to remove. My tip here would be not to chip away the slag using a hammer. This can ruin the quality and look of the final weld. I would suggest that you drag your chipping hammer along the slag, this should do the trick.

If some parts of the slag are a bit more difficult to remove then you can always resort to chipping.

HOW TO CORRECTLY HANDLE AND STORE THE 7018 ELECTRODE?

A lot of beginners think that welding rods are just metal pieces that can be handled roughly as they are meant to be burned anyway. But welding rods are the product of their environment. What I mean is that the way you store and treat your welding rods will reflect the quality of your final weld.

The 7018 electrode is especially susceptible to storage issues. This is due to its low hydrogen content which is very sensitive to moisture, water, and other contaminants. So what actually happens if the electrode comes into contact with moisture? Excess hydrogen and water will get introduced in the weld. This moisture gets heated during the welding process and forming small bubbles on top of the weld. This will heavily influence the quality of the weld both in terms of its integrity and strength but also its looks.

The 7018 electrode is so susceptible to moisture that you cannot leave it outside or near water for more than a couple of hours. I have come across a lot of people who either don’t store it at all or do something which they feel will work, but it never does.

Most of these ‘home remedies’ rarely ever work. Not storing your electrodes properly will not only destroy the integrity of the weld but will waste all of your remaining electrodes.

SOME HOME REMEDIES WHICH YOU SHOULDN’T FOLLOW

There are some common mistakes that people make while storing their 7018 electrodes, these mistakes or myths have been around for a really long time. More and more people are getting educated about the correct way to store their electrodes. Let’s take a look at some things which you shouldn’t do.

  • The first thing that a lot of people do is wrap their electrodes in plastic and store them in the freezer. I don’t know how this practice started but this is exactly the opposite of what you should be doing.

The moment you take out your electrodes from the freezer, the cold electrode will come in contact with the warm air and introduce moisture to the flux.

  • Another thing that is very widespread and not just with amateurs but even in industrial usage is using an old refrigerator as a welding oven. Usually, people will fit a light bulb inside it to create some heat and that’s it. I don’t know about you but I have never come across a light bulb that can create temperatures of up to 250-450F?
  • The third most common practice I have come across is using a home oven to re-bake the electrodes. This sounds very logical in the beginning, you can use a home oven to take the moisture out of the electrode. There is one problem though, re-baking electrodes require temperature of about 500-600F and if you try this with your home oven then you better make sure you have a fire insurance.

HOW TO CHECK IF YOUR ELECTRODES HAVE BEEN EXPOSED TO MOISTURE?

If you don’t know the signs of moisture exposure then it can be difficult to know if your electrodes are still in good condition or not. There are different levels of damage that can happen at different levels of exposure.

If your electrode has only been left outside for a few days but there has been no direct contact with water then you might see some porosity in the final weld. It is difficult to know if there is any damage at this level of exposure. The only way would be to conduct an X-ray test or through destructive testing.

Some “minor” exposure to moisture will result in visible porosity along with internal porosity. You may also see some cracks and a rough bead structure. The slag might become more fluid and it could become much more difficult to remove.

If the moisture exposure is severe then, there will be some under-bead cracking and external cracking, severe porosity, and a poor weld appearance.

SOME OF THE STORAGE OPTIONS YOU CAN GO FOR

There are a lot of storage options in the market at the moment, ranging from amateur use to professional ovens. You can find one in your budget and you won’t have to spend a lot of money on it. This is one of the most important investments you can make in your welding career. The money spent on a decent welding oven will easily make up for the destroyed electrodes you will have without it.

First things first, if you cannot afford a welding oven or any other storage solution then only buy the amount of 7018 electrodes you are going to need.

Some of the rod ovens have a built-in thermostat through which you can exactly control the temperature. These rod ovens come in all sizes. Starting from the portable options, I would suggest that you go for these if you don’t have a lot of storage needs. They are not only cheaper (you can get a decent one for less than 200$) but they can also be transported very easily.

The next level is the bench electrode oven, they have a much higher capacity and can be about the size of a small fridge. You probably won’t need this unless you are a professional welder.

Welding flux ovens are the grandest and the biggest of them all, they can range up to 10,000$ and are strictly meant for industrial uses.

You can also use the Lincoln hermetically sealed containers, they are pretty cheap and are perfect for storing small amounts of electrodes. Once they are opened you will have to store them at 250-300F.

portable rod oven

7018 ELECTRODE STORAGE TEMPERATURE AND RE-HEATING

The moment you open the container of 7018 electrodes, you are working against time. you have to be quick and store the electrodes at temperatures ranging between 250-300F while keeping them away from any kind of moisture.

The complicated part comes in re-drying the electrodes if they have been left out in the open or if they have come in contact with any kind of moisture. So what is re-drying? If your electrode has come in contact with moisture or air then re-drying will restore it to its original or near original level.

If the moisture exposure has been severe then even re-drying might not bring back your electrodes. If after re-drying you notice the coating to be fragile or flaky or if there is a change in the arc characteristics then you might have to discard the electrode.

There are two levels of redrying, when the exposure is minimal and when the exposure has been significant. In the latter, you will have to do pre-drying as well. Remember that you don’t need to pre-dry for more than 2 hours. This process will minimize flaking or oxidation of the coating.

Another piece of advice would be to spread the electrodes in the oven evenly as all the electrodes will need to reach the re-drying temperatures. Below is the temperature chart for re-drying 7018 electrodes.

Level of exposurePre-drying temperatureFinal re-drying temperature
No direct water contact, exposure to air for a week or lessNo need700-800F (370-430C)
Exposure to high humidity or direct water180 to 220F (80-105C)700-800F (370-430C)

HOW TO SELECT THE RIGHT AMPERAGE FOR YOUR ELECTRODE?

This is one of the most contentious topics among welders, even regular welders can have a hard time selecting the right amperage for the job. There are a lot of factors to take into account like the thickness of the base metal, the welding rod size, type of electrode, and even the position you are going to be welding in.

Remember that the suggestions I am going to be making are just an estimate. You will have to experiment a little to see what suits your job the best. If you have access to the manufacturer’s recommendations then keep those as the baseline suggestion.

The first factor is the electrode selection which in this case is the 7018. The second factor is the size of the electrode you are going to be using which will depend on the job at hand.

As the welding rod’s diameter increases so do the amperage requirement. As a general rule of thumb, you should increase the amperage by 30Amps for every 1/32 increase in diameter.

Following is the amperage selection which you can keep in mind with different thickness electrodes:

SizeAmperage range
¼” or 6.4mm320-400
1/8” or 3.2 mm110-165
3/16” or  4.8 mm200-275
3/32” or  2.4 mm65-100
5/32” or  4.0 mm150-220
7/32” or 5.6mm260-340

Choosing the right amperage is something which you will learn through practice and experience so don’t be disappointed if you are unable to get it right the first time.

More welding rod tables & charts here

RELATIONSHIP BETWEEN THE WELDING POSITION, AMPERAGE AND ROD SIZE SELECTION 

Your welding position can affect the size of the rod you are using and it will also affect the amperage that you will be running.

If you are welding in an overhead or a vertical position then you want a weld puddle that is easier to control and therefore you should go for a smaller electrode size compared to the flat position.

Your amperage settings will also change. If you are using the same electrode size for horizontal and vertical welds then you have to remember one thing. The change in amperage is not meant to create different levels of heat. You will need to change the amperage so that the heat created is the same. Let me explain.

If you are welding in the overhead position then heat will rise and collect on the base metal. This will increase the heat and you will have to lower the amperage to compensate for this. You should reduce the amperage on an average by 5%.

Similarly when you weld in the vertical up position then lower the amperage by about 10% as the heat will increase near the top of the metal.

RELATIONSHIP BETWEEN THICKNESS OF THE BASE METAL, SIZE OF THE ELECTRODE AND AMPERAGE SELECTION FOR 7018

A general rule of thumb to follow here, a lower amperage is preferable for the thinner base metal. This is simply because thinner pieces cannot tolerate a lot of heat and they tend to warp Similar is true for the opposite.

The base metal size heavily influences electrode selection as well (this rule is only indicative and the real-life usage can change a lot). There is a general rule here, for single side single pass butt welds up to 3/16” thick, you can go for an electrode that is a step thinner. For example if the metal is 1/8” thick then you can go for a 3/32” electrode.

This rule can vary a lot, you can select a smaller electrode and still perform the weld. The only thing to keep in mind is that you should rarely go for a rod that is thicker than the base metal. The exception being very thin base metal, like 17 gauge or 1.4mm.

The following table will give you a good idea about the relationship between the size of the base metal and the electrode size to use with it. Remember that these are just indicative and you might have to experiment a bit with the electrode sizes.

Electrode diameterMetal thickness
1/16”Up to 3/16”
3/32”Up to ¼”
1/8”Over 1/8”
5/32”Over ¼”
5/16”Over ½”
3/32”Up to 1/8”
Electrode size vs metal thickness

EFFECT OF TEMPERATURE OF BASE METAL ON AMPERAGE

If the metal you are going to be working on has a very low temperature then you might have a hard time starting the arc, or it might stick to the base metal. There are two things you can do here, either increase the amperage slightly or pre-heat the base metal.

SIGNS THAT YOU ARE WELDING WITH A LOW AMPERAGE

A lot of welders out there, especially the cheaper ones display the amperage differently. There is a possibility that you set the amperage at 100Amps but the real output is 85Amps. In this case, how do you find out if you are welding with lower or higher amperage settings? There are a few signs including the look of the arc, the welding pool, electrode behavior, and weld quality.

Some of the most common signs of lower amperage setting can be:

  1. Difficulty in striking the arc
  2. The electrode will keep sticking during the weld
  3. The arc might look dim or weak
  4. Inconsistent sound of the arc
  5. The weld puddle might be too small or narrow
  6. Poor weld bead quality, not enough deposition
  7. Slower travelling speed

SIGNS THAT YOU ARE WELDING WITH A HIGH AMPERAGE

Some of the most common signs of a high amperage setting can be:

  1. The weld bead might be too wide
  2. The travelling speed can be much faster
  3. The arc will look brighter than usual and sound erratic
  4. Hard to control puddle
  5. Higher amounts of spatter

COST OF THE E7018 ELECTRODE

The prices of any electrode can vary depending on the region you are in. If you go to Amazon (Affiliate link alert!) then currently the Forney 7018 30685 1/8” electrode set of 5lbs can set you back by 15$. The same electrode from the same brand of 3/32” will cost around 14.5$ and the 5/32” will cost about 15.5$. As you can see there is not a lot of difference among different sizes.

The Forney 30805 E7018 rod in 5lbs packages cost about 23.75$ for the 1/8”, 21.88$ for 3/32” and 26.31 for 5/32”. While the Hobart 770474 E7018 1/8” costs about 32.77$ for the 5lbs package. So there will be some differences in the same electrode offered by different manufacturers.

Forney 6011 and 6013 1/8” in 5lbs packages cost almost the same as the 7018 but there might be some slight changes in your region or in your local store.

FREQUENTLY ASKED QUESTIONS

There was a lot of information we just went through and naturally it can get a bit confusing at times. I have addressed some of the most common questions that people have related to the 7018 electrodes. I hope this will help clear some things up.

WHAT IS THE OPTIMUM STORAGE TEMPERATURE FOR THE E7018 ELECTRODE?

You should ideally be storing the 7018 electrodes between 250-300F in a welding oven.

WHY SHOULD YOU KEEP THE 7018 ELECTRODE AWAY FROM MOISTURE AND AIR?

The low hydrogen coating of the electrode is very susceptible to moisture which can lead to porosity and poor quality welds. You should not keep the electrode out in the open for more than a couple of hours.

WHAT IS THE TENSILE STRENGTH OF THE FINAL WELD OF THE 7018 ELECTRODE?

The first two digits of the 7018 electrodes denote the final weld strength. In this case, it would be 70,000psi.

WHAT IS “RE-BAKING” AN ELECTRODE?

If your electrode has come in contact with water or has been left out in the open for some time then re-baking helps to restore the electrode to its near-original state. This is done by heating or “baking” the electrode at about 600-700F to remove the moisture.

WHERE SHOULD THE 7018 BE IDEALLY USED?

The 7018 electrode is perfect for structural industrial use like pipeline welds, bridges, containers, and complex joints. If you get your hands on AC 7018 rods and you also have the storage capacity, then it can also be really great for home or farm repairs

CONCLUSION

The E7018 electrode is one of the most popular welding rods out there. This is because of its ease of use combined with its excellent weld quality which is not only aesthetically pleasing but structurally sound as well. You also need to be very careful while storing these electrodes as the low hydrogen coating is very sensitive to moisture and water. Coming in contact with water can ruin the quality of your welds. Also, pay attention while selecting the amperage settings for the job, but don’t worry if you don’t get it right at the first attempt.

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