How to set up a mobile welding rig

Dec 22, 2023

Exploring different truck options in conjunction with application needs will help you to determine the best possible option. Images: The Lincoln Electric Co.

When out in the field, mobile welders can encounter a range of different projects and applications. It’s important to set yourself up for success. With so many different types of technology and equipment available, it may be hard to know where to start.

Kristina Yamaguchi, product manager of commercial engines and Theo Facaros, manager, construction and rental sales at The Lincoln Electric Co., Cleveland, Ohio, break down what you need to consider and explore in order to properly set up a mobile welding rig that works for you.

The type, style, and size of a work truck will dictate many features, particularly equipment capacity, of a mobile welding rig. It’s important to start with the basics, but also plan for future growth and expansion.

“Real estate on the back of a truck is going to play a significant role on how the mobile rig is set up,” said Facaros. “In many cases, size of the welder will take priority over functionality. The space on the truck will dictate not only the size of the welder but also what other equipment can be included.”

Oftentimes, a bigger welding power source will include more functionalities, but it also will be heavier and take up more space. However, the trend is to make the truck as small and as light as possible, which will undoubtedly save money. If you believe that a lighter, gasoline-powered, aluminum body truck makes the most sense for your fleet, understand that trucks like this, are best suited for smaller, lighter power sources; while others require more equipment options, which typically leads to a heavier truck.

Truck configuration also matters when adding an air compressor. According to Facaros, the majority of mechanics’ trucks will have an air compressor on it somewhere. Looking for a truck that has air compressor under mounts, some connected straight to the engine, can be beneficial and eliminate the need to have the compressor sitting on top of the truck bed, making space for other equipment.

Beyond that, it is important to know exactly what to add to the truck. Do you want a crane, welding power source, and/or generator? How much weight will these pieces of equipment add to the truck? This will determine how heavy and what class the truck needs to be.

Exploring different truck options in conjunction with application needs will help you to determine the best possible option.

Beyond the truck weight and size capacity, one of the first things you need to know is what you are welding. The majority of today’s welding power sources have multi-functionality, meaning that they have both welding output and power generation capabilities.

“These are really the simplest options you can go with,” said Facaros. “You typically won’t find a mobile welder without some sort of generator power. It can get a lot more complex as more functionalities are added, like an air compressor, battery jumper or start, or hydraulics. You can really go from a two-in-one to upwards of a six-in-one.”

Look for something that is easy to set up and is feature-rich without being too heavy or expensive. This Lincoln Electric Ranger 330MPX welder/generator offers multi-process capability for stick, TIG, MIG, gouging, and pipe applications. It has a 20 percent smaller footprint and is 25 percent lighter than other machines in its class.

It is important to ask questions like what will the mobile welding unit typically be used for? Are you going to be doing light welding using a small stick electrode? Or, will it be heavy gouging? For example, a truck that is used on railroads will need a lot more welding output and maybe some type of compressor, like air or hydraulic, built into it like air or hydraulic.

“The challenge is that the majority of mobile welders don’t know what they are going to weld on a day-to-day basis,” said Facaros. “They are called out to a site to be able to weld, let’s say on heavy steel because maybe a bucket on a bulldozer broke, all the way down to some light work on a fence railing. So having a sense of the type of work that can be expected is essential to setting up that rig.”

There are a handful of major welding processes, but two are mostly used on service trucks: Shielded metal arc welding (also known as stick welding) is generally the most common due to its versatility and simplicity, and a wire process like flux-cored arc welding (FCAW) or gas metal arc welding (also known as MIG welding), which needs wire and potentially gas but can help increase productivity.

“The key is to be as productive and flexible as possible,” said Facaros. “But we typically recommend starting small and working your way up. For example, you could start with a 260-amp welder which will offer flexibility on the welding side and include a generator, enabling you to perform the majority of work needed.”

Do you have a preference on fuel type? Gasoline-powered welding machines tend to be smaller and lighter. Depending on your truck capacity, this might be of value based on space availability.

A diesel-powered welding machine typically is heavier. It’s important to note that machines below that 300-amp range are usually gasoline-powered. While you might find a gasoline option in the 300-amp range, anything in or above the 300-amp range is where you will find diesel-powered machines.

While diesel power sources tend to cost more up-front than their gasoline counterparts, they tend to be more fuel-efficient and can last a long time with preventive maintenance.

When deciding between the gasoline and diesel-powered machines, size and weight matters.

“Truck class and size might determine or eliminate which welder to go with,” said Facaros. “A 300-amp diesel welder is going to weigh between 750 to 1000 lbs., whereas a gasoline 300-amp welder is going to weigh around 450 lbs., which is how light our Ranger 330MPX welder is.”

On top of that, adding functionalities not only increases the machine’s price, but its size and weight as well. The benefit of a multi-functional power source is that if it has built-in capabilities, for example a compressor or battery jump that might eliminate the need for secondary machines and equipment.

Evaluating the size and weight is essential.

“Start small and work up,” said Facaros. “This is especially important in the introductory phase, where piecemealing equipment tends to make the most sense. An air compressor is generally one of the cheapest accessories and can be added to almost any truck, so that’s a good starting point. When deciding on the right welder, it’s important to look for a machine that helps you do your job fast, easy, and well.”

Look for something that is easy to set up and is feature-rich without being too heavy or expensive. There are some welding-focused features that may be more beneficial than ancillary capabilities like battery charge or the like.

“For example, a feature like Ready.Set.Weld is a intuitive push-and-turn digital control for operators that might not know exactly what type of work they will be welding from one job to the next,” said Facaros. “It allows operators to set the machine based on what they are welding, and it will tune in the welding procedure. It will also determine the amperage based on the thickness of the material being welded or type of alloy you’re welding on. If one day you are welding thick carbon steel with a 5/32-in. electrode, then the next day welding stainless steel with a 3/32-in. stainless steel electrode, it will determine the different set of parameters.”

In mobile welding applications, you might work closely to the truck or be hundreds of feet away. Portable wire feeders are generally available in two configurations: basic across-the-arc or those equipped with an added control cable.

“CrossLinc Technology feeders and remotes enable voltage control at the feeder, while eliminating the extra cable,” said Facaros. “This allows the operator to control the amperage, voltage, or welding parameters remotely without having to walk across the site to the welder to readjust it. This is beneficial not only for ease-of-use while helping improve productivity but also for operator safety.”

Beyond that, field equipment must be robust enough to handle rugged environments. However, that does not mean that you can ignore preventive maintenance practices.

“This is why we’ve added a maintenance screen on some of our welders,” said Facaros. “This digital user interface on the front of the machine will send out reminders and alarms when oil, fuel filters, air filters, and spark plugs are due for a change. It is an easy way to send reminders out, so that when you are out in the field, you have an efficiently working welder that is up for the task.”

The Lincoln Electric Co., www.lincolnelectric.com