How can you weld with a car battery and a coat hanger?

Using the battery as a power source and the coat hanger as your filler rod, you can successfully weld. However, it’s better to link more than one battery together. This will allow you to achieve the proper amount of amperage needed to start and sustain the arc. And while it’s possible to weld with a car battery and coat hanger, it’s not advisable under normal circumstances.

The process of welding contains within it a variety of safety concerns. From the white-hot light of the arc to the intense heat of molten metal, there are dangerous conditions every time you weld. Attempting to weld with a car battery and a coat hanger further intensifies these safety threats.

However, because it has been successfully done—and it’s pretty cool—we’d like to introduce you to welding with a car battery and a coat hanger. Keep in mind that we don’t condone you try this at home. In fact, we strongly urge you to be as safe as possible when you weld. Just know that if you do get into a sticky situation, a little bit of metal rod and a power source could get you unstuck pretty ingeniously.

Why Learn to Weld with a Coat Hanger and Car Battery?

After reading the title of this article, you might have wondered why. Why would I want to do that? Why would I need to weld on-the-go and use a car battery and a coat hanger?

While these are all valid thoughts, there are many reasons why. For instance, knowing how to weld with the resources at your fingertips could mean the difference between life and death. On a less dramatic note, knowing this welding trick could get you home or at least to safety if you’ve broken down.

Like any other life skill that serves us well only in that one very specific, very crucial moment, welding in this manner may seem trivial and irrelevant to everyday welding. But think of what you could do if you didn’t want to buy a welder but needed to do just a few spot welds. Or how you could finish up a project if your welder broke and all you had was a car battery and a coat hanger. There are many more applications for welding in this manner than you might first think. Keep it in mind and we hope you find it useful someday. You may never know when you’ll need it.

Basics of a Welding Circuit

Before we discuss this crazy welding method any further, let’s first consider the basic process involved in welding. This will help us to better understand what’s going on between the car battery and the coat hanger. Really, once you know which component takes the place of which traditional pieces, the rest is nearly self-explanatory.

We all know that welding requires intense heat in order to melt metal together. That’s the quick definition of welding. But do you know what the individual components are?

First, you’ve got the power source. Most often this is the welder itself, which includes within it a positive and negative source. Depending on what type of welder you’ve purchased, it could be spitting out either direct current (DC) or alternating current (AC). Whichever it may be, the welder itself creates the electricity needed to bring heat to the work piece.

An electrode cable brings the electricity from the welder to the electrode, which directs the welding arc to the workpiece. Technically, it is to the ground that the arc connects but since that ground is connected to the workpiece, power disperses here instead. The work cable, i.e. the ground cable, connects back to the welder for a complete circuit.

And there you are, in the middle of it all, welding away happily.

Now that you’ve got a better idea of what the cycle looks like, let’s take that model and turn it on its side. Can you guess which components the car battery and coat hanger will replace? How do you think the circuit will look? Keep reading to find out if you’re right.

A Poor Man’s Welder: Explained

We really should have called it the MacGyver’s welder. In any case, let’s get down to the nitty-gritty. How exactly do you weld with a car battery and a coat hanger?

As far as materials goes, you’ll need:

• A charged car battery
• A coat hanger
• A set of jumper cables

It’s also a good idea to have some sort of welding helmet, gloves, and a flat surface to weld on. You’ll obviously need the part you’re attempting to weld (back) together, too.

Once you’ve gathered these materials, gear up. The welding will begin momentarily. But first, link the negative battery terminal to the piece you’re going to weld. Then, attach the coat hanger to the positive terminal. You’ve nearly completed the welding circuit. The last step is to strike an arc on the piece you’re welding and initiate the flow of energy from the battery to the workpiece. If you’d like to see another video of this process, check out this Popular Science article.

Requirements for Welding with a Coat Hanger and Car Battery

Though the phenomenon of a car battery and a coat hanger creating welds sounds great, there are a few catches. First and foremost: a lack of sustainable power. One user on the GarageJournal.com forum states, “Yeah, one battery @ 12V DC is not quite enough voltage to run a welding rod. Two batteries in series @ 22-24V DC is close to what a ‘typical’ 3/32-1/8 inch SMAW/stick welding rod runs at (close, but not quite). Three batteries @ 33-26V DC is a bit too much voltage.” Intense heat lies at the core of welding. If your car battery isn’t able to produce a high enough temperature in the arc, penetrable welding won’t happen easily. At the same time, having too much power can force your hand in the opposite direction. Your welds will melt too far and you’ll have an entirely new problem on your hands.

That is one of the drawbacks of welding this way as well. Whereas a typical welder allows you to adjust settings depending on what your application is, this makeshift welder isn’t so forgiving. In fact, you’re limited to what the DIY welder is capable of at that time. And if you find that your car battery isn’t fully charged, your welding time could go from minutes down to seconds.

Another requirement necessary to welding with a car battery and a coat hanger is the coat hanger itself. While welding rod is really what we’re after, a coat hanger will suffice for the filler metal needed to support the weld. Since many coat hangers are plastic nowadays, it may be harder to find a metal coat hanger in the first place. Also under consideration should be the coating on the hanger, which may burn up and release chemicals during use as a welding rod.

Safety Tips

Working with unpredictable conditions, like those found in welding with a car battery and a coat hanger, requires an extra bit of caution. Keep the following in mind as you weld and be sure to keep safety at the front of your mind.

• Weld with two batteries for steel that’s less than ¼” thick. If you’re attempting to weld anything bigger than that, you’ll need at least three batteries.
• “Amperage of the batteries is going to be very important. If you have larger batteries from a truck with higher cranking amps you are going to get a better result.” The more power you can give the arc, the better your welds will be.
• You will not have any control over the voltage/current. You will be welding “on the fly,” as it were.
• Find yourself without a welding helmet? Simply look away from the arc. If that’s not as easily done as it’s said, put on a pair of sunglasses. While these may or may not reduce the arc light enough to be bearable, they will at least provide some protection.
• Loop the coat hanger around a magnetic object for a smoother arc. It should boost the welding circuit with a smidge of inductance.
• If you want to increase your welding time, link the batteries in parallel. That means each terminal is connected to the corresponding one on the next battery (negative to negative and positive to positive). For a higher output, “you want to wire the batteries in series.”

Before you attempt to weld using the MacGyver-like car battery and coat hanger method, take a moment. Research the topic more and watch tons of videos. The more you know about how to safely recreate this welding life hack, the better.

Your Next Welding Purchase

Welding with a car battery and a coat hanger will definitely get you some respect. However, is it really practical to be welding this way all the time?

If you think about it, “it is just as reasonable to buy a generator that also lets you weld. Or buy a small arc welder to use along with a portable generator.” Most entry-level welders are reasonably priced and you can easily pick them up at your local hardware store. They’re rated for use from home and hobby to professional. You won’t have to worry about electrocuting yourself and they’re much more reliable than any car battery and coat hanger. So while it may seem good to stow these materials in your car for a rainy day, there are alternatives.

For example, Popular Mechanics recommends Trail Weld. “Trail Weld is a portable welding kit, containing cables to connect two or three 12-volt car batteries in series, which will allow you to make welding repairs from anywhere.” This handy grab-bag of DIY welding tools may well find its place next to your first aid kit. All you have to do is supply the welding safety gear, such as gloves, and you’re set. Best of all, this could be the Christmas present you’ve been looking for to surprise the welder in your life.

The bottom line remains: a commercial welder theoretically ranks higher when it comes to safety than this car battery and coat hanger welder you can rig up in a few minutes. That being said, it does have its place. There’s nothing wrong with trying your hand at welding with a coat hanger and car battery. Just be sure you’re practicing safe behaviors and do us a favor. Keep a fire extinguisher on-hand, for peace of mind if anything.

Further Welding Hacks

We’ve shared with you one of the ways you can create a welder in a hurry. But if you’re looking for more when it comes to welding, check out the other articles we’ve posted. You may find something you’ve never even heard about before. Better yet, you could learn new techniques and skills that will get you one step closer to becoming a master welder. After all, it’s the first step—or should we say weld?—that counts.