Tech - The Basics Of Welding
Tackle your own metal repairs on your vintage Mustang project
While the typical vintage Mustang still with us has been on this earth for 40 years or more, many are far from perfect. Years of abuse from less than perfect drivers, northern and coastal rusting, storage in damp locations, and more mean that the typical Mustang project you could be purchasing is going to need some metal work. The metal work needed is often the impetus as to whether a Mustang comes home with a new owner or not. We often recommend purchasing the most solid Mustang project you can find, as it will save you a lot of money in the long run with your project. However, in today’s economy we often have to do more with less, and that often means buying a less than perfect Mustang project, right? That doesn’t mean that you have to shell out more to fix your Mustang if you’re willing to invest a little time and effort to learn how to weld and repair your project yourself.
Often, we see a Mustang and think it’s too far gone or will take many thousands of dollars to fix the rusted and damaged metal, but with a small investment in your own welding equipment and some practice, you could bring a Mustang once ready for the scrap yard back to life and give it a second chance. Once you have a welder, you’ll wonder how you lived without one. From major sheetmetal repairs to fixing the neighbor kid’s bicycle, it will become another indispensable tool in your garage shop.
Where do you start with your welding training? First and foremost is knowing all of the dangers of using welding equipment and the safety aspects of using a welder. Second is actually choosing your welding equipment based on your budget, needs, and work space. Another thing to consider is whether you want to use flux core wire or MIG wire, which requires shielding gas to be added to your welder. You’ll also need to think about the available voltage in your work area. Finally, there’s the education and training needed to use the equipment properly. We only have so much room to delve into all of these areas, but we’ll give you the highlights and show you where you can learn more. Before you know it, you’ll be laying down a serious bead and bringing a once dead Mustang back to life for yet another generation to enjoy.
Just like any other tool in your garage, welding equipment requires a certain amount of skill and training to use and has specific safety aspects to deal with. Welding equipment, and for the purpose of this article we’re focusing on the typical MIG (metal inert gas) process, uses high voltage electricity, creates intense heat and sparks, gives off fumes, produces arc rays (both ultraviolet and infrared), and produces electric and magnetic fields which can interfere with pacemakers. Let’s take a look at these safety issues and how best to protect yourself when using welding equipment.
You’ll find that enthusiast level MIG welders generally use 115-volt household current, though you’ll also find some that use 230-volt current. Like any electric power tool, the importance of grounding is imperative—properly grounding the welder, insulating yourself from the equipment, and using only in dry areas. You’ll also be dealing with the amperage of the wire-fed welder itself when you strike an arc between the welder’s feed wire and the work piece. Amperage is how a wire-fed welder works, by running a current through the feed wire that melts when it comes in contact with the work piece that is in contact with the ground electrode.
Besides the electrical danger, the most important safety aspect is the proper protective gear. We’ve all seen the television shows where somebody is restoring a car or building a motorcycle and they’re welding away in a t-shirt and no welding helmet. As the saying goes, “Don’t do as I do, do as I say.” Whether it’s four hours of hard-time welding on a floor pan or just a few minutes to tack together some brackets, you need to be using all of the required safety equipment.
Protecting your body begins with a full-length sleeve shirt or jacket made from treated cotton or other non-flammable material. Stay away from synthetics, as they can easily melt by sparks or molten slag and burn you. Also be sure to wear heavy work gloves made of leather or other suitable material, and of course a welding helmet. Many welders also wear a “doo rag,” or even an old baseball cap, under the helmet to protect their heads and necks from hot metal. You’ll be surprised how much flies around when welding and it is easy for a bit of slag or a spark to bounce around inside the helmet, so many companies recommend safety glasses to be worn along with the helmet. Arc rays can easily burn your skin (think sunburn, not contact burn), which is why a full-face helmet along with arm and hand protection is so important. Without them, the exposure of your skin to these rays can cause all sorts of long-term issues.
Welding gives off gases/fumes that can be dangerous too. Never weld on a piece of coated metal unless the coating has been ground away. Coatings like cadmium, galvanizing, and others give off toxic fumes. While it is important to maintain the flow of shielding gas for a quality weld, the gas itself can cause problems if allowed to build up in a work area, so always ensure there is proper ventilation when welding.
While not as serious as electrical or arc ray damage, hearing damage is also something to be considered. Long-term effects are the issue here, as the constant “sizzle” of the welding arc can take its toll when welding constantly over the years. Of course, when welding on sheetmetal during a restoration project, you’ll often encounter hammering, cutting, grinding, and other noisy jobs, so we always stress to “put your ears on” and wear protective ear muffs, or at the least in-ear protection, during your time when working on your project in your home garage or shop.
One last thing to consider is the electrical and magnetic field (EMF) produced by the welder in use. Anytime an arc is struck, an EMF field is created around the welding equipment and metal being welded. Any person wearing an implanted medical device, like a pacemaker, should seek consultation with their doctor before using the welder. Things you can do to limit your risk include ensuring the welding cables are to the side of you and not one on each side. It is also best to tape or tie-wrap the cables together as well. Do not coil or hang the welding cables on your body. Secure the work piece clamp as close to the welding area as possible. Finally, do not sit or lean on the welder while using it.
Buying a Welder
As we mentioned, we’re concentrating on MIG welding for this story, as it’s the most popular welding process for automotive repairs and fabrication. It’s also one of the easiest forms of welding to learn. We’ll also briefly discuss TIG welding for those who like to work with aluminum and the plasma cutter for those situations where you need to cut metal fast and precise. We understand everyone has a budget limitation, but don’t buy a cheap welder. You’ll only be hurting yourself in the wallet, as you’ll most likely end up buying a better welder down the road. It’s okay to buy used equipment if it was taken care of and checks out. This is one of the few areas where it is best to buy name brand, as it is infinitely easier to find service parts and consumables for popular welders like Lincoln, Hobart, Miller, and others than it is something from a lesser available and known brand.
While we’d all love to have a shop full of welding and fab gear, generally starting off with a good MIG welder is going to get you pretty far with your project, especially if all you plan to do is weld in new metal to your Mustang project. TIG welders are great for aluminum fab work if you’re making your own oil pan or aluminum brackets, but otherwise isn’t critical for sheetmetal work. The same goes for a plasma cutter. Much of the bad metal you need to cut out can be done with a reciprocating saw, cutoff wheel, or even an air chisel, so you don’t necessarily “need” a plasma cutter. As such, we’re going to concentrate on MIG welder choices and just touch on other equipment that would be beneficial to rust repair and metal work as your budget allows.
MIG welders are available in several styles, including stationary, mobile, and even some with built-in power sources for remote job site work. For the typical home shop, we’ll concentrate on stationary and mobile units. Most small workshops can get by with a stationary MIG welder that you carry to the job location and set on the floor (optional rolling carts are available). These welders usually can be powered by 115-volt household current, making them easy to use anywhere around the house. The downside is often duty cycle, or the amount of time a welder can be used at a certain power level in ten minute increments. For example, if a certain setting says it has 70 percent duty cycle, that means the welder can be used for a solid seven minutes and then must be left to cool (with its internal fan on) for three minutes before being used again. For most welding where you’re placing a tack here and there and then a few one-inch stitches, duty cycle may not be a factor, but if you plan long stitches of welding, then duty cycle is something to consider.
Mobile welders have built-in wheels and a handle to allow easy movement around the shop, but due to their larger size and capacity they are often tougher to fit in smaller shops/garages and usually require 230-volt input voltage. So unless you have the proper wiring into your workshop space to power it, you’ll have to do some wiring upgrades to your garage. Or course, the duty cycle on 230-volt welders is higher as well. Lastly, the larger 230-volt welders allow you to weld thicker materials. If all you expect to do is automotive sheetmetal and raw material up to about ¼-inch, a 115-volt welder will suffice, but if you plan on welding thicker materials, like frame rails, crossmembers, and subframe connectors, then you should seriously consider the 230-volt machines.
So you’ve boned up on all the proper safety precautions, you’ve researched your equipment, and you’ve setup your new machine with some welding wire and shielding gas. You’re ready to melt some metal together right? Hold on a second there skippy; you’ve got more learning to do. Creating a good weld that is safe and securely bonds your work pieces together takes some training and knowledge.
First, you have to know the type of metal you are welding, as well as the thickness of the metal, so you can properly setup your MIG welder’s wire feed speed and voltage to produce the best welds. You also have to determine the best way to approach the work piece (not everything is a straight weld on a work bench), including positioning the MIG gun, electrode extension, and gun travel speed. No two welding jobs are the same. Every time you fire up your welder it is recommended to test your settings on a scrap work piece to ensure your settings are correct. Just assuming your welder is properly set because the job is similar to something you’ve done in the past can mean poor weld penetration, excessive spatter, burn through, or porosity of the weld.
It has been said that applying a good MIG weld sounds like sizzling bacon, and while this is true, it is not something a beginner should rely on by sound alone. During your initial use, and until you are comfortable with your new equipment, it is best to pick up some scrap metal in the thickness you intend to weld (damaged fender from a body shop, some old angle iron brackets, etc.) and practice on these parts, learning what your welder can do and the proper settings, before striking the first arc on those pretty new quarter panels.
After speaking with various welders, pulling from our own experiences, and reviewing the massive amounts of training materials you’ll find on our sources’ websites, we’ve come up with these additional tips to consider before you strike that arc with your new welder.
- Keep the MIG wire feeding mechanism at the right tension and clean of any dirt or grease.
- Some welders prefer to push the gun, others pull, but both methods are correct in specific circumstances. Pushing the gun will give less penetration but a wider bead, while pulling the gun will do the opposite (narrow bead and more penetration).
- Keep the gun tube/liner as straight as possible to minimize wire feed speed issues.
- Use both hands to steady the gun for better looking welds.
- Tack weld pieces first and then finish weld, being sure to move around to prevent heat warpage.
- Use the proper shielding gas. Typically an Argon/CO2 mix is used for thinner steels in automotive work.
- Know your machine’s duty cycle for the settings you are using and let it cool for the proper time frame.
- Don’t let people watch you weld without the proper safety equipment in use on them as well.
A complete safety rig like this Lincoln Electric Ready-Pak offers everything you need to be safe while welding in one convenient package. The kit includes a Viking auto-darkening welding helmet, welding jacket, leather and traditional MIG gloves, safety glasses, and “doo rag.” You can be all set and ready to go for under $300.
Over the years many of us have sourced heavy work gloves for grinding, perhaps even a work jacket, so you might have much of what you need to get started welding safely, except for the welding helmet itself. A nice auto-darkening helmet, like this Viking 2450 series, will fit the bill nicely. Lincoln Electric carries a full line of helmets, including some trick licensed graphics from Chip Foose, Iron Man, Captain America, and others.
While the majority of those reading will be using a MIG welder for panel replacement and light on-car fabrication, if you find yourself making lots of small parts or repairing small items, you may wish to invest in a welding table, like Miller’s Arc Station. The Arc Station provides a secure welding surface with material clamps, yet easily folds out of the way when not in use.
Welding metals together takes knowledge of your machine’s settings, but there are also general rules of thumb to go by for material thickness, type of gas, and wire size. One quick way to get close to the optimum settings is with a welding calculator. You can find them on numerous welding supply sites, and Miller even has an iPhone app to put a calculator right in your pocket.
Thanks to our friends at Lincoln Electric, here’s a visual representation of what a good weld looks like, along with a whole lot of bad welds due to various improper settings and user error. These welds were produced using short circuit transfer mode and a typical weave pattern bead. From left to right: -Proper wire feed speed, voltage, electrical stick out, and gun travel speed -Wire feed speed too slow -Wire feed speed too fast -Electrical stickout too short -Electrical stickout too long -Gun travel speed too slow -Gun travel speed too fast -Not enough gas coverage (low bottle pressure, regulator set too low, etc.
Welding wire comes in several diameters, each of which is capable of welding a range of material thicknesses. As you can see by this chart (courtesy of Miller Electric), .035-inch wire has the greatest range and what you will normally find in most machines at body and fab shops. However, for those just starting out, .030-inch wire is easier to weld on thinner metals like sheetmetal. So if you’re planning on a lot of sheetmetal/panel replacement work, you might want to consider spooling your machine with .030-inch wire.