Welding on the Farm: Selecting a Welding Unit for the Farm or Ranch

Welding repair and fabrication on the farm 

Typical farm/ranch welding applications include:

• Welding the steel frames (tubes) in place for a milking parlor
• Patching the sheet metal on combines and other equipment
• Repairing aluminum irrigation pipes 
• Mending wagons, seeders, spreaders and other machines that can break down in the field
• Repairing the flighting on augers
• Welding together the self-locking panels in the feeding alley of a free stall barn or the slats for a hog's holding pen
• Constructing fences
• Hardfacing skid loader buckets and tillage equipment
• Reattaching an A-frame hitch on a cattle trailer
• Repairing stainless steel sprayer tanks
• Fixing aluminum engine manifolds

Because different applications sometimes call for different welding processes, selecting the right welder for your operation is important.

The most common welding processes used for fabricating metals are stick, MIG, flux-cored and TIG welding. Note that MIG and flux-cored welding can be performed by the same machine, and that TIG machines can usually stick weld, too.

Unfortunately, there is no single welding process suitable for all welding situations. For this reason, it is necessary to weigh the advantages and disadvantages

What size welder should I buy?

One way of classifying the "size" of welding power sources is by how much amperage they can generate at a given duty cycle. Duty cycle is the number of minutes out of a 10-minute cycle a welder can operate. For example, the Millermatic® 252 MIG welder can deliver 200 amps of power at a 60% duty cycle. It can weld continuously at 160 amps for six minutes, and then must cool down during the remaining four minutes to prevent overheating.

Next, consider that thin metals require less amperage and thicker metals require more amperage. For example, to MIG weld 18-gauge steel in a single pass takes roughly 70 amps, where welding 1/4 inch steel in a single pass requires roughly 180 amps.

The phrase “in a single pass” is the key, because multiple passes can be made to weld thicker material. However, this takes more time, so you may exceed the machine's duty cycle and spend more time waiting than welding.

For light repair work on steel, stainless steel and aluminum — from sheet metal to material 3/16-inch thick — a 130- to 150-amp MIG unit with a 30 percent duty cycle can perform many of the welding jobs a farm or ranch requires. For heavier repair or fabrication jobs — trailer hitches, axles, hardfacing — consider a 200- to 250-amp MIG unit with a 40 to 60 percent duty cycle, or consider a 175- to 250-amp stick machine.

Remember, you need sufficient amperage to ensure proper penetration on the root (first) pass, and you cannot make up for a poor root pass with subsequent passes. Actual amperage used depends on the type of weld (butt, lap, fillet, corner), welding position (flat, vertical down, vertical up, overhead), electrode diameter, type of shielding gas, and other factors. 

Portability

Can you bring the work to the welder, or does the welder need to go to the work? And if you bring the welder to the work, is power available? Small welders, like the Millermatic 211 MIG unit, weigh about 38 pounds and operate off 120 or 240 volt household current. By running a flux-cored wire, you can eliminate the need for a shielding gas bottle for added portability. Small stick welders are also portable.

For repairs or breakdowns that occur far from an electrical outlet, consider purchasing an engine-driven welder/generator, such as the Miller Blue Star® 185 or Bobcat™ 225 welder/generator. Not only do these machines provide their own welding power, they also provide auxiliary power to run tools and lights. Many people keep the generator in a truck bed, enabling them to drive to wherever repairs are needed.

While basic engine drive units like the Blue Star can only stick weld, the larger engine drive units are often multiprocess machines capable of stick, MIG and TIG welding by adding the right accessories.

Should I buy a stick, MIG or TIG welder? 

Stick

Traditionally, most farms and ranches have a small AC stick welder, primarily because they cost a few hundred dollars. While stick welders are great for general repairs on steel or for hardfacing, they do have drawbacks:

• Welding thin materials may be difficult or impossible. Even skilled welders would hesitate before attempting to stick weld sheet metal (18 ga. steel).
• Marginal for welding aluminum (and takes a lot of skill).
• You must clean the slag off the weld, a messy and time-consuming job.
• Stick is a slower process than MIG.

Stick does have its advantages beyond its lower price tag. Because the electrodes are self-shielding, they are better suited for windy, outdoor conditions than MIG or TIG. Stick is also more forgiving than MIG when welding on dirty or rusty metal. (Still, it is always advisable to scrape or grind off paint, rust and other debris; welding on the cleanest material possible produces a stronger weld.)

If you plan to purchase a stick welder, try to buy an AC/DC welder. For most applications, DC reverse polarity welding offers advantages over AC, including: 

• Easier starts
• Fewer arc outages and sticking
• Less spatter for better looking welds
• Easier out-of-position welding
• Easier to learn
• Smoother arc
• Welds thinner metals better

MIG

While an old stick welding pro may disagree, learning to MIG weld is easier. With a little practice, even a first-time MIG user can achieve a good-looking weld. This means that anyone can use it.

For the farm or ranch, a MIG welder probably offers more advantages than any other welding process. The advantages of MIG welding are:

• Easiest welding process to learn. 
• Welds light-gauge material or thick plates.
• Welds all common metals —carbon steel, stainless steel and aluminum.
• High welding speeds can be obtained — up to four times faster than stick welding — reducing repair or construction time. 
• Increased efficiency: 50 pounds of MIG welding wire yields 49 pounds of metal deposition, where 50 pounds of stick electrode rods yield approximately 30 pounds of deposition.

A further advantage is that the same equipment used for MIG welding also performs flux-cored welding. Rather than running a solid wire coupled with a shielding gas, flux-cored welding uses self-shielded wire with flux inside.

The advantages of flux-cored welding are:

• Less affected by drafts, so better suited for outdoor work.
• Works as well as stick on rusty or dirty material.
• Continuous wire feed process, which minimizes starts and stops.
• Deep penetration for welding thick sections.
• Increased metal deposition (two or three times that of stick welding), which is beneficial for hardfacing.
• Can eliminate need for a shielding gas bottle, which increases portability.

Between its MIG and flux-cored capabilities, a wire welder can perform any task a stick welder can and do it more efficiently. While a good quality wire welder costs $450 to $4,000 (depending on its size), the costs for wire and gas are much less than that for stick welding rods. Coupled with the ability to weld aluminum and sheet metal, a wire welder can pay for itself very quickly.

TIG

This welding process uses a non-consumable tungsten electrode and a shielding gas that protects the welding area from contamination. The concentrated heat and precise control of the TIG arc allows thin material (.010 inch) to be welded. The advantages of TIG welding are:

• Precise welding on thin materials is easily accomplished, plus there is less distortion overall.
• Provides the highest quality work, as well as highly aesthetic weld beads.
• Allows the welder to adjust heat input while welding by using a foot or hand amperage control.
• Welds steel, aluminum and other metals with just a single gas, argon.

Although TIG welding is a relatively slow process, it provides high quality welds. Typical applications are for aluminum irrigation pipes, stainless steel sprayer tanks and aluminum engine parts.

Another factor to consider is that TIG machines also have stick welding capabilities (they are often referred to as TIG/stick w