Arc welding is one of the most common welding types, and its simple mechanism and reliance on electricity instead of gas give it some interesting benefits and uses. It’s incredibly versatile, and you can do it virtually anywhere.
That brings up a few more questions, like what exactly arc welding is and how to do it. And, more importantly, what do you need and how do you use it? It’s time to answer those questions.
How Does Arc Welding Work?
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The official term is “Shielded Metal Arc Welding,” often shortened to SMAW. For simplicity, we call it arc welding or stick welding, due to the electrical arc shooting out of a stick-shaped electrode.
Arc welding uses electricity to heat the metal to its melting point and fuse things together. As the filler metal and electrode attach to the material and then solidify, you get a strong welded joint.
The electricity comes from a constant-voltage power supply which typically operates on DC, although AC options do exist. This power supply connects to the welding rod holder and to a grounding clamp which you attach to the metal. Striking the area with the electrode ignites it and starts melting the filler.
Essentially, electricity comes out through the welding rod and arcs to the metal, which creates temperatures of up to 7,000 degrees Fahrenheit. Since the power supply has a constant voltage, only the amperage fluctuates with the arc length.
As the electrode melts and sprays onto the metal, it nestles in and creates a welded joint. Thanks to its protective coating, oxygen won’t contaminate the weld and make it brittle. That’s why we call it “shielded metal arc welding.”
Necessary Arc Welding Equipment
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Arc welding setups are simple, and there are only four main parts:
- Electrode holder
- Power supply
- Grounding clamp
- Stick electrode
Regarding power and maximum thickness recommendations, these are guidelines and manufacturers often play them up to sell you more expensive things than what you need. About 140 ampere is enough for practically anything you’ll encounter, and even 120 or 130 will be enough in most cases.
However, those may take longer or require more than one weld, so 140 is a good target.
Next, you’ll need safety equipment. These items are NOT optional or anything you can compromise on. Welding is hazardous without proper equipment, so make sure that you have the following:
- Welding mask helmet
- Leather welding gloves
- Long-sleeve non-flammable jacket
- Non-flammable pants
- Fire-proof boots or shoes
- Fire extinguisher
- Proper ventilation or a respirator
Now, with these items on hand, you’ll have everything you need. Just make sure that you get high-quality gear, or you may end up seriously injured.
What Can I Do With Arc Welding?
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Arc welding is an ideal option for industrial construction, pipe welding, farm equipment repairs, and structural steelwork. However, it’s not very good for sheet metal or anything thinner than one-sixteenth of an inch.
This is especially true for aluminum. For such tasks, you’ll want a MIG or TIG welder.
As for materials, arc welding works great on steel. You can even weld regular and stainless steel together. Nickel-based alloys and chrome work fine too. Although aluminum can be somewhat tricky, it works as long as it’s not too thin.
What’s more, arc welding works even in rain and windy conditions, which isn’t true for gas welding. Also, it does a great job on rusty and painted metal.
Arc Welding Pros & Cons
It’s easier to understand the capabilities of arc welding in a broader context. So, let’s look at its advantages and disadvantages against other welding methods.
- Simple, inexpensive equipment
- Works in all weathers
- No need for shielding gas
- Works well on most metals
- Changing electrodes is quick and easy
If you’ll be tackling many different metals and alloys in different conditions, arc welding is an excellent choice. Plus, the simplicity of changing electrodes makes it easy to adjust to different metals in quick succession.
- Ineffective on thin metal
- Uses many electrodes
- Leaves some slag
- Takes longer than other welding methods
Arc welding can be a slow process sometimes, and welding rods don’t last very long. Also, it doesn’t work with reactive metals like tantalum, titanium, and zirconium.
How Long Does Arc Welding Take To Learn?
The learning curve is relatively steep, but it depends on what your goal is. If all you aim for is the ability to do basic repairs around the garage, you may only need a few hours of practice before you can lay a functional weld.
However, it probably won’t be pretty, although you’ll improve steadily over time.
For an entry-level welding job, you’ll need proper training for at least 500 hours. Make it double for intermediate positions. If you’re looking for a well-paying career as a welder, you’ll need a year or two of training.
Basic Arc Welding Safety
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As any experienced welder can tell you, welding is not something to take lightly. Without proper care and safety equipment, you will doubtlessly have accidents. In fact, you risk serious injuries or even death, but respecting safety removes those risks.
Firstly, you’ll need to wear your protective clothing. Next, you must ensure proper ventilation if you’ll be welding in an enclosed space because welding fumes are very toxic. A ventilation fan is an excellent solution to this.
Then, there’s the issue of what we call “flash burns.” Flash refers to the ultraviolet light radiation coming from the welding flame. That’s the same stuff that causes the sun’s rays to burn your skin, and flash burns do the same thing but much faster.
You may not notice flash burns right away, but later you’ll notice blisters and irritation. It’s even worse if you expose your eyes to the flash, which will cause severe discomfort or even damage your eyesight.
Also, you may still experience stray metal droplets and sparks that can catch onto your clothes and burn your skin. Therefore, wearing something thicker like a leather jacket and boots is wise.
Next, be careful in hot and rainy conditions. Welding while wet can lead to nasty electrical shocks. Plus, both these shocks and the aforementioned stray sparks become very dangerous if you don’t keep everything flammable at a safe distance.
Setting up for arc welding
Before you begin arc welding, you should clear the area you’ll weld of rust, paint, scale, and water. These elements can worsen even the finest of welds, and welding tends to draw water in from the rest of the surface. Drying and grinding the area an inch or two back until shiny is a great rule of thumb.
There are many different stick electrodes for arc welding, and they have codes on them that let you know what each is for. However, that requires understanding the designations.
The two you’re most likely to come across are E6010 and E7018, although the E isn’t always present these days. The 6010 is a good all-rounder that works well on rough and dirty metal and is ideal for open root welds. This electrode gives a deep penetration that burns off lots of rust and junk and welds nicely at all angles.
The 7018 is a milder option with a lower penetration that’s better-suited for finer welds. It’s the go-to electrode when you want a nice-looking joint on clean steel.
For stainless steel, you’ll probably want to use E308L-16 or E309L-16. The former is better for joining stainless steel pieces together, and the latter is better for fusing stainless and regular steel.
If you want to arc weld aluminum, you’ll typically use an E4043. However, you’ll want to preheat thick pieces of aluminum to help them weld, but don’t overheat and melt the target area.
What do these numbers mean, then? The first two numbers refer to the tensile strength of the filler metal. Using the earlier examples, a 6010 has a minimum tensile strength of 60,000 pounds per square inch while a 7018 can withstand 70,000 pounds. That’s about twice as strong as your typical A36-grade steel which can take 36,000 pounds.
As for the last to digits, they indicate the flux or shield of the welding rod. Higher numbers indicate a more substantial deposit of flux and metal when you weld. In other words, the 6010 has far less shielding than the 7018.
Striking an arc
Firing up the arc is the first hurdle you’ll face when arc welding. You strike it like a match, so it’s pretty simple, but the arc will sometimes go out when you’re new to arc welding.
Sometimes, the rod will stick, and flux may chip off and ruin part of the stick. That’s part of the normal learning curve, and you’ll only get past this with practice. You can fix a damaged rod by using it on a piece of scrap metal, keeping the arc about a quarter-inch long to burn off the chipped flux.
It’s easiest to strike a good arc if you wear good welding gloves.
First, make sure they’re dry. Then, place the rod over it and use it to balance it as you strike. When the arc fires, place your supporting hand back on the handle.
Welding machine setup
Now it’s time to configure the welding machine. This is easiest if you let the crackling sound of the burning rod guide you. Strike an arc, and then adjust the amperage until you get a nice crackle. The rod should burn evenly.
If it’s sticking, it’s not hot enough. If it turns red, it’s overheating.
Now, the welding process itself isn’t something you can learn by reading. So, here’s a video that’ll help you get started.
Ready For Arc Welding?
That’s all you need to know about arc welding. Are you looking to get your first arc welding setup? If so, we have information on picking the right stick welders and affordable welding helmets.
Do you have any comments or questions about arc welding? Feel free to leave a comment below.