Restoration Corner
Bruce Adams

Home Workshop Welding Systems

There are many skill sets required in a complete frame-up restoration project. Tasks requiring some of those skill sets, such as engine machining and finish painting, are best left to professionals who have the experience and proper tools to complete the job efficiently and safely. Some by contrast – disassembly, sanding, and parts cleaning – are obviously done by the cost-conscious “D-I-Yer” because they require little skill and don’t justify the payment of professional shop rates.

Metal fabrication, especially welding, falls in between. On the one hand, it is a restoration skill that requires many years of experience to become an “overnight sensation.” It is an art as well as a science. However, if you are a committed do-it-yourself home auto restorer, you can learn the basics to do a lot of tasks yourself, provided that you have the right tools to do the job properly. Here are a few suggestions to send you along the correct path to success.

Two of the most common welding processes used in metal fabrication are tungsten inert gas (TIG) welding, also known as gas tungsten arc welding (GTAW), and metal inert gas (MIG) with its variation of flux-cored arc welding (FCAW). Each of these processes has its own unique set of benefits and limitations, and each works well in some welding applications, and not well in others. Your project will most likely require a diverse range of welding applications, from sheet metal to frame rails. There’s no one-size-fits-all process that will work on all of these applications, so I strongly recommend careful analysis – supplemented by spending a little time watching a professional at work with these various processes – before investing in equipment and training.

TIG welding 

Tungsten inert gas welding is an arc-welding process that uses a non-consumable tungsten electrode to produce the weld. The weld area is protected from atmospheric contamination by a separate shielding gas (usually argon), and a filler metal. A constant-current welding power supply produces energy that is conducted across the arc through a column of highly ionized gas and metal vapors known as plasma.

TIG welding is most commonly used to weld thin sections of alloy steel, stainless steel and non-ferrous metals such as aluminum, magnesium, and copper alloys. The process allows the welder greater control over the weld than other welding processes, producing stronger, higher-quality welds.

TIG welding is comparatively more complex than other methods, but provides the highest quality precise welds. We use TIG welding, for example, when restoring the aluminum Mercedes-Benz cylinder heads. Jobs requiring TIG welding may best be left to well-equipped shops with considerable experience in the craft.

MIG welding

Metal inert gas welders use a wire-welding electrode on a spool that is fed automatically at a constant pre-selected speed when the welder presses the trigger switch on the wire feed. Like TIG welding, a separately supplied shielding gas protects the weld from atmospheric contamination.

The arc, created by an electrical current between the base metal and the welding wire, melts the wire and joins it together with the base, producing a high-strength weld with great appearance and little need for cleaning. MIG welding is clean, easy and can be used on either thin- or thick-plated metals.

A slight variation of MIG welding – flux-cored arc welding – is similar in that it is also a wire-feed process but differs in that it does not require a shielding gas. This gas-free welding application uses flux-cored wire to shield the arc, and is a simple, efficient and effective welding approach, especially when welding outdoors, in windy conditions or on dirty materials. The process is widely used in construction because of its high welding speed and portability.

Both MIG and flux-cored arc welding are very easy to learn and can create extremely clean welds on steel, aluminum and stainless steel. Both processes can weld materials as thin as 26-gauge and are ideal for auto restoration and working with body panels.

If you’re thinking about getting involved in welding in your home projects, I recommend MIG welding as the best starting point. You can’t do every kind of metal joining required for a complete restoration with a MIG welder, but you can do many specific tasks, which will result in both personal satisfaction and cost savings; learning MIG welding is very worthwhile.

There are large selections of MIG welders suitable for home workshops currently on the market. Some are priced below $500 and appear on the surface to be a good value. However, our recommendation is to spend a little more on the investment – which is true for all shop tools – and stay with the industry leaders known for quality and parts support. These welding suppliers include Miller, Hobart, and Lincoln, to name a few, recommended because as your experience grows with use of your first purchase, you will need to rely on a family of welders, accessories and warranty. All of the major players offer a growth path, excellent options and accessories. And it is much easier to protect your investment in the resale market. A quality welder will be an investment for a lifetime of service and a great opportunity to build your personal skill set.

Selecting your welding system

We use Miller products here in our workshop. The Millermatic MIG line of products as described at www.millerwelds.com/products/ is a good starting point to look at the range of welding machines available. The typical way to classify a welding machine is by how much amperage it can generate in a given “duty cycle.” Duty cycle is the number of minutes out of a 10-minute period a welder can operate. For example, a Millermatic 140 115-volt unit can deliver 90 amps of welding output at a 20-percent duty cycle. It can weld continuously at 90 amps for two minutes, and then must cool down during the remaining eight minutes to prevent overheating.

If you are taking on a restoration project yourself, no doubt you will be saving a significant amount by doing all the welding. My advice is to invest some of that savings into a quality 230-volt MIG machine. The entry point for a 230V welder is the Millermatic 180. This welder has a duty cycle of 30 percent at 135 amps. The listed price is $1,060, and with the 230V power, can weld up to 5/16 inches in a single pass with a smooth, spatter-free start.

We highly recommend the Millermatic 180, which can be purchased at www.cyberweld.com for a lower cost of about $964 that includes free shipping; you can’t beat that. This website also offers all the safety equipment you require. Don’t let the 230-volt requirements scare you. If you have a 240V clothes dryer in your garage, you have your power source. If not, simply hire a qualified electrician to install the connection according to your local building codes.

Our shop uses Miller equipment. Based upon our experience, the overall reliability and performance is second to none. Our most versatile machine is the 252 using 0.035 steel wire with an additional 30-amp spool gun using 0.047 aluminum wire for all types of aluminum repairs/fabrication.

Safety first

Honey, I think I just set the house on fire! All do-it-yourselfers know not to take shortcuts with personal safety when getting up and running with welding. The national Occupational Safety and Health Administration (OSHA) reports an estimated 1,000 eye injuries occur in American workplaces every day; mechanics (experienced and novices alike) share the majority of risk.

Professional auto repair instructors recommend that home mechanics get used to wearing a pair of safety glasses any time they’re in the garage workshop. Protective eyewear is inexpensive and can even be stylish. If you wear eyeglasses, ask your optician to make a set to OSHA eye-protection safety standards.

For metal fabricators, eye protection is only part of the picture. Welding safety in the workshop starts with equipment that is set up properly. Any time you’re welding, you should also be wearing protective attire.

Proper set-up

Ensure your welder is on a flat surface away from any water or flammable materials, including paper, cloth rags, oil and gasoline. Avoid working in wet conditions because water conducts electricity. Verify proper grounding. A metal-on-metal connection that is unimpeded by paint or other foreign material is the proper ground. Never use chains and wire rope as grounding connectors.

When using gas cylinders, chain them securely to a stationary, upright support or cart at all times. When moving or storing a cylinder, fasten the threaded protector cap to the top of the cylinder. Use only gas hoses designed for welding.
Keep your work area free of clutter. This promotes safety and helps increase efficiency by making necessary equipment and tools easy to find. Cables and hoses can create a tripping hazard; organize the workspace to minimize the number of cables underfoot. Coil up excess hose when finished to prevent kinks and tangles.

Examine hoses regularly for leaks, wear and loose connections. A quick spray with a soap and water mixture will create bubbles indicating a leak or loose connection. Immediately replace any faulty gas hoses with new hoses. Duct tape has many workshop applications, but it is never the solution for a leaky hose.

Welding fumes can be hazardous, so ensure your workspace is properly ventilated. In smaller workshops like a home garage, it’s a good idea to leave a door or window open and run a box fan as an exhaust, sucking fumes away from your breathing area. Better yet, install an exhaust fan in your workshop to exhaust harmful fumes. Sparks fly as you weld – again, clear all flammable materials. Never leave your workshop immediately after welding. Provide a safety window of at least one hour to prevent smoldering sparks from flaring up and burning down your garage or worse.

The welding equipment includes a ready reference chart that shows the correct specifications for welding time and materials required for each type and thickness of steel being welded.

Proper welding attire

Arc welding produces sparks and metal spatter and emits intense visible and invisible rays, all of which pose hazards to unprotected skin and eyes. Shorts, short sleeves and open collars all leave you vulnerable to burns from both flying sparks and the arc rays. Wear only flame-resistant work clothes and button your cuffs and pockets to prevent them from catching sparks. Pants cuffs, too, can catch sparks and should be avoided. High top leather shoes offer the best protection in footwear; tennis shoes and other cloth shoes are inadequate because they can catch a spark and smolder unnoticed.

Always wear proper gloves when welding or handling recently welded material to protect you from sparks, arc burns and the heat from the work piece. Mechanic-style gloves are not recommended for welding, as they are not flame resistant. Use heavy-duty welding gloves and avoid picking up or holding hot metal with your hands.

Even a quick tack weld requires the use of a welding helmet. Any exposure to the arc’s radiation may cause symptoms such as a burning sensation or eye irritation commonly referred to as “arc flash.” Repeated exposure can lead to permanent injury, so always wear proper face and eye protection – including safety glasses underneath the welding helmet – when welding or when exposed to a welding arc. Again, safety glasses should be a requirement in your workshop, especially whenever you are grinding and cutting; get accustomed to putting them on each time you enter the shop.

Auto-darkening helmets offer the best solution if your welding needs require different processes, i.e., MIG, stick, and TIG. Auto-darkening helmets vary greatly in their response times to the light of the arc, generally between 1/2,000 to 1/20,000 of a second. Helmets also differ in the level of lens shade. Inexpensive helmets stay at a fixed No.10 shade, but good ones are adjustable between shade No. 9 and shade No. 13.  The nice thing about adjustable shade is that you can get set up and maintain the right welding position without having to flip up your helmet. This is also nice while welding in a tight area where flipping a helmet isn’t possible.

A quality welding helmet and gloves are essential. This setup includes a “corrective lens” that can be inserted into place quickly to aid the welder in seeing a magnification for close-up work.

Tips for Welding Success

• Build a base of knowledge before tackling your own projects by taking a welding class or watching online videos.
• Practice on spare sheet metal before tackling expensive body panels on the car.
• Talk to experienced welders for their pearls of wisdom. The smallest tip can go a long way.
• Get to know your local welding supply shop for supplies, gas rental, and warranty service. They can always provide invaluable advice.
• Be aware of fire hazards associated with welding in your garage. Make it a habit to clean up the shop before leaving. A clean shop is a safe shop and clean-up allows time to detect any smoldering from stray sparks in unexpected spaces.
• Hear me now, think about it later, and believe me tomorrow when I say, “Safety First.”

Expert metal fabricator and welder George Carling at work on the undercarriage of a 190SL.