Rust and cracks in auto panels can be easy to fix, but people often skip these repairs. They think of them as costly or time-intensive. But with the right tools and guidance, it can actually be a very simple process. Welding might seem like an intimidating skill and many professional and home-repair techs avoid it. But it doesn’t have to be a challenge. Technology has improved, and now anyone can learn the basics.
This isn’t to say you will learn overnight–good welding takes plenty of practice to perfect. But it’s definitely not something you have to avoid or ignore.
When Do You Need to Weld
Welding is most useful for bodywork and larger structural jobs. As a car owner, you’ve probably run into some these problems already: a cracked panel, a rust patch, or a puncture in the body of the car. Maybe you discovered a cracked chassis, a cracked muffler, or a rusted oil pan. These repairs are easily accomplished with a MIG welder and a bit of know-how. You’ll save time and money by fixing the problem itself instead of replacing entire parts.
Welding will give you more control over your repair process. You’ll be able to accomplish more tasks and more intricate projects. It’s a must-learn skill for vintage car restorations. If your project is rusted through, patch it instead of replacing panels. Patching a leaky oil pan with materials you already have on hand will save time, money and materials for any job.
Types of Welding and What’s Best for Automotive Sheet Metal
There are a few main types of welding that could be used in automotive repairs. Let’s look at three, but the last will be the most important for you to learn.
TIG stands for “Tungsten Inert Gas” welding (Also known as Gas Tungsten Arc Welding or GTAW). The tungsten is used for the electrode that creates the welding arc. This isn’t usually the best type to learn for a beginner but can be great for very fine projects. Filler metal is usually used to create the fusion between the parts you’re joining. In this case, two hands are required – one for the welding nozzle and one for the filler. Also, a shielding gas is pumped through the nozzle to keep the arc steady and strong.
Stick welding, also known as Shielded Metal Arc Welding or SMAW, used to be the most common form of welding. It also uses a filler metal, like TIG. But it’s not as precise. The high heat of stick welders makes this process unsuitable for thin metals. It’s also ugly, leaving a lot of splatters. It’s great for construction but not so much for anything on a car.
MIG, or “Metal Inert Gas” welding (aka Gas Metal Arc Welding or GMAW) also uses a gas shield and filler material. However, in this case, the filler is a wire fed directly through the welder. That makes this a one-handed process. So you can keep the other hand free for manipulating your materials and other tools. MIG welding is quicker than most other welding methods. It’s not as precise as TIG but is still relatively clean. It’s also much easier to learn and can be a great place to start learning.
MIG is going to be your go-to welding type for most auto-body repairs. It works best because it is good for many types of metal and is suitable for quick repairs. It can handle a wider range of thicknesses than TIG or Stick. MIG can handle the materials used in auto bodies without sacrificing strength or clean appearance.
The newer MIG welding machines also have tons of options that make it easy to avoid distortions. It’s also one of the easier processes to learn. For seasoned veterans and new welders alike, it’s the best choice for auto repairs. MIG welders are by far the go-to welders for beginners because of the simplicity and ease of use.
What Kind of Tools Do You Need?
There are a few tools you’ll need to start welding. Some of them have come up already, but I’ll give a few examples to help figure out which things you’ll need to get started.
The Welder itself is the first and most vital part of your welding toolset. Plenty of companies offer MIG welders which come with presets to give you the proper voltage, gas, and temperature for any project. This makes it easy to use right out of the box. These tools have the knowledge behind them to hold your hand as you learn.
It is a big investment (although less than a TIG machine), but picking the right MIG welder means you’ll be investing in more than a “beginner” tool. It also is one that will excel even when you’re at the point of mastering the skill.
To run your MIG welder during a project, you’ll need a couple of consumable items that you want to keep well-stocked. There’s nothing worse than doubling your project time because you need to run out for supplies!
One is the filler wire. The type of wire you’ll want will depend on the metals you’re working. It comes in various materials and weights. Match the wire to the base metal.
Shielding Gas is also crucial. A gas made up of 25% CO2 and 75% argon will cover most weld projects. But look into different options to see how they’ll affect your welding process
There are also other tools that will be a big help when you’re patching sections of your project. You probably already have most if not all of these. Not all of it will be necessary for every project, but these tools will be very useful to have around.
- Angle grinders for cleaning up welds
- Pneumatic saw for making thin cuts and lining up fits
- Aviation snips (clockwise and counterclockwise) for cutting patches
- Locking welding clamps for keeping the metal in place while you weld
- Dollies for hammering out metal or heat sinking during and after welds
- Body hammers for evening out metal
- Sheet metal gauge for matching your patch size and your MIG settings
Spot weld drill bits are also useful. They can remove previous spot welds when disassembling the pieces you’re going to patch. They’ll prevent doing excessive damage to good metal.
And finally, and most importantly, safety gear. Please, don’t try to weld without the appropriate protective gear. Not only will you endanger your own health and wellbeing. At the very least you’ll need:
- Welding gloves
- A welding coat to prevent burns
- A welding helmet to protect your face and especially your eyes from the intense light of the welding arc
Some Tips for Auto Welding
If you’ve haven’t done any welding before, practice making and breaking different types of welds. This will help you learn the techniques and also show the feel and strength of good welds. Use scrap metal in different sizes so that when you get started on your car, you feel confident in your skills.
When you’re finally working on real cars, remember to take your time getting set up. A good setup is the key to the best weld. Make sure all your materials are ready to use. Keep your station free of any potential fire hazards.
This also means taking your time focusing on the steps that lead up to the weld itself. Sizing your patch is an essential skill. It may add some time in the beginning, but it will save you hours of cleanup and patching later. Remove ½ to ¾ of an inch of good, clean metal around the area you intend to patch. Keep corners rounded to prevent heat buildup which will cause distortion. Check your metal gauge. When it comes time to cut, precision is key (This is where that pneumatic saw is useful!). A flush weld is going to look and hold better than a lap weld. Measure twice, cut once!
When placing your pieces, tacking helps keep things lined up well and in place as you work on the rest of the weld. A single tack will keep a piece flexible in the event that you need to move it out of the way. Use tacks at several different points when you want to hold a piece in place. This will keep it stable as you fill in the weld, and also prevent some distortion.
And finally, always be careful of distortion. Poorly distributed or excess heat in your metal causes the metal to bend out of shape. Move your welding point and keep the heating time short. This will reduce distortion, keep your patch looking great and save hours of frustration.
Welding is a rewarding new skill for anyone who works on cars. It has its challenges, but hopefully, you can see that it doesn’t have to be frightening or mysterious. I hope that this breakdown of MIG welding components makes you feel prepared to give welding a shot. With the few tips outlined here, you’ll be miles ahead of most people just starting out. The ease of modern MIG Welding means that, with a little guidance and a lot of practice, you’ll be breezing through tricky welds in no time.
Greg Sanders is the owner of Cromweld.com, a website devoted to all things welding. Greg is semi-retired from welding but likes to keep learning, as well as sharing his knowledge through his website. You can also find him on Facebook.