Farm Implement Maintenance and Repair

Farm Implement Maintenance and Repair

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Weld repairs on the farm are diverse and can come at the worst times. This article details proper welding repair techniques and explores equipment - such as the Bobcat™ 250 welding generator and Millermatic® series of all-in-one MIG welders - that will make welding repair on the farm much easier.

Planting season isn’t just one of the toughest times of the year for the farmer, it’s also one of the toughest times of the year for equipment. And there’s not much that’s as frustrating as time lost to a broken implement.

Whether it’s a bent haybine jack, a crack in a combine hopper or a dozer frame that snapped in two, equipment breakages can be more than a simple nuisance, they can keep you from harvesting your crops and even endanger your safety.

In an ideal world, your equipment would break at the end of the day right next to the shop so you could just take it back into the shop and fix it properly and quickly and get it ready for the next morning.

In the real world, however, metal brackets and jacks are more likely to follow Murphy’s Law than your planting schedule and break down at the most inopportune moment and as far as possible from the shop. In those situations, Chris Roehl, a product manager with Miller Electric Mfg. Co. offers a racing analogy as a general rule of thumb for deciding how to approach the repair.

“In the middle of a race, a pit row mechanic is going to do whatever it takes to get that car back on the track,” Roehl explains. “So if you can get a welding generator out there, make a quick weld and keep harvesting, that’s what you should do. Then, at the end of the day, you should bring the implement back to your shop and take some time making a proper repair. If there is a safety issue involved, though, you don’t want to risk losing a limb or even your life for a couple more hours in the field.”

Joel Ort, a technician with Miller, agrees. He notes that fixing the crack or hole right the first time will save you from having to fix it again next harvest season.

“A lot of times I’ll see equipment that developed a crack and people will think there is something wrong with their welding skills or their welder when the crack reappears,” Ort said. “Usually, though, that happens because they failed to properly prepare the piece before welding.”

In order to avoid having to deal with recurring cracks, Roehl and Ort offer these suggestions for getting the repair right the first time.

Clean the Surface

“One of the most common problems farmers have in making good, solid welds is that they don’t grind the dirt, oil, paint and corrosion from the metal before welding,” Ort explains. “Stick welding is more forgiving of dirt than MIG or TIG welding, but you still need to have the metal relatively free of foreign material.”

The points on this lift system began to wear almost clean through the tube, so it was taken apart and the grooves were filled in to make it as good, and possibly better, than new.

A common hand-held die grinder, wheel grinder or wire brush should suffice for most repairs. It is also important to clean off the area around the crack or hole so that contaminants don’t make their way into the weld puddle or heat-affected zone and thereby weaken the weld.

Cleaning the material to be welded is extra important when welding aluminum, which might look clean but still have a layer of aluminum oxide on the surface. “Aluminum looks nice and shiny because it doesn’t rust, but it forms a layer of aluminum oxide, which will make it very difficult to weld and trap impurities in the welds,” Roehl said.

Establish a Good Ground

Welding equipment relies on electrical current making a complete circuit from the power source to the material and back to the power source. The stinger and electrode (in Stick welding) or just the wire (in MIG welding) provide one connection from the power source to the material; the ground clamp provides the other connection.

In addition to cleaning the material being welded, it’s important to remove any paint and corrosion from the piece where the ground clamp will attach. “A lot of guys will have problems striking an arc and keeping it lit when it’s simply a result of not cleaning the material enough to establish a good ground,” Ort said. A better grounding connection is also achieved by placing the clamp as close to the weld location as possible.

Grind out Cracks and Holes

This is perhaps the most important and frequently overlooked step in making a lasting weld. “Typically, if something breaks or forms a crack, a lot of people will just take their MIG or Stick welder and just pull the trigger and weld over the crack,” Roehl said. “Well, unfortunately, that crack may be a half-inch deep. When you just put a little weld over the surface, it might only penetrate 1/8-in. deep, so you’re not penetrating all the way to the root.”

Several portions of this no-till drill were ground out and rewelded in areas that are prone to cracking or breaking at high stress points.

To ensure adequate penetration and a lasting weld, Ort recommends grinding or drilling the crack out all the way to the other side of the metal, as well as just beyond the length of the crack on each side. “There are people who will say that completely drilling it out isn’t necessary,” Ort said, “but I would recommend it. Even where it’s not cracked, there can be stress within the metal that could cause it to crack somewhere down the road.”

Roehl noted that a similar procedure is advisable for holes worn or cracked into buckets and other implements that use thinner metal. “Let’s say you just take a welder and fill in a hole the size of a half-dollar, but you don’t do anything about the little spider cracks that form around it,” Roehl said. “What happens is that those cracks continue to grow and cause other holes and problems.”

Instead, Roehl recommends grinding out the metal around the hole to determine how fatigued it is. “If you’re grinding and chips are flying all over the place, that means the metal was very brittle. To repair a half-inch hole you might need to weld a three-inch coupon over it.

Use Multiple Passes

Another source of recurring frustration for farmers is that, hoping to save time, they will weld slower thinking they are achieving greater penetration into the base metal. Not so, Roehl says.

“Don’t hesitate to make multiple passes,” Roehl advises. “What can happen when you have a deep crack to fill in is you go real slow so you put more filler metal in, but you’re actually going to be welding on top of the puddle instead of getting into the base metal. The filler metal is just sitting on top of the base metal then; it’s not penetrating it.”

Stick welding produces a layer of material called “slag” that must be chipped and brushed off the weld after each pass. One of the biggest benefits to MIG welding is that it doesn’t create slag that must be chipped off after each pass and the farmer can make multiple passes without any additional preparation.

Self-shielded wire, which can be fed through a MIG welder but has the advantage of being impervious to wind, also produces slag that must be chipped off before attempting multiple passes.

The main frame on this John Deere 4430 dozer head cracked in two, so it was ground out, re-welded and this extra plate was added for strength.

An important step to remember when welding aluminum is to fill in the concave crater at the end of the weld. If the crater is left too concave, it will start cracking up the length of the weld. To avoid crater cracking, Roehl recommends letting the puddle cool for two seconds when you get to the end of the weld and pulling the trigger again briefly to fill in the crater until it is flush with the rest of the weld or even sits a little higher.

Use the Right Welding Equipment

“Quarter-inch steel is like sheet metal on farms,” Roehl notes, “so they’re really not going to be adequately served by a 135 or 175 amp machine. A farmer would be able to use a smaller machine like that for multiple passes, but what will happen is they’ll exceed its duty cycle and have to wait several minutes for it to cool down before they can make another pass.”

For MIG welding, Roehl recommends a machine with a 200 or 250-amp output with a duty cycle of at least 40 percent at the rated output, such as the Millermatic 210 or 251.

This farmer is using a Bobcat™ 250 welding generator to power a Millermatic® 175 MIG welder equipped with flux cored wire for this hitch repair.


If you want to be able to weld out in the field, a multi-process welding generator, such as the Bobcat™ 250, is able to Stick, MIG, flux cored or TIG weld (with the correct accessories) while at the same time providing 10,500 watts of power for lights or virtually any other tools you might need in the field.

Take Care of your Welding Equipment

It’s tough to keep your machinery in good shape if your welder isn’t. Because welders vary by make, manufacturer and the type of welding they do, the best way to ensure your welder is operating at its peak is to follow the manufacturer’s recommended maintenance schedule.

There are, however, some general tips that will help keep all welders and accessories in good condition.

For engine-powered welding generators, Ort said the oil, oil filter and air filter should be changed at least every 100 hours of operation. Somemodels require oil changes every 50 hours.

Farms that don’t use their generators that much in a single year should change the oil, oil filter and air filter each spring. Spark plugs should be checked roughly every 200 hours of use and cables and hoses should be checked and replaced if broken every 500 hours. Farms who don’t use their generators very much should also add a conditioner and stabilizer to the gas tank, or in the case of diesel engines, an anti-gelling agent in the winter.

For most welders, both engine powered and not, it’s a good idea to take the cover off a couple times a year and blow off the dust and dirt that can build up inside. Due to the sophisticated components in most modern welders, especially MIG and TIG welders, specific problems with a welder should be sent to a certified technician for repair.


Welding can be a great solution to many common problems on the farm, but appropriate safety precautions — many of which are common sense — need to be taken to avoid injury.

Working with electricity is always a potential safety hazard, so before you weld, make sure all of your outlets, wires and electrical connections are in good working order and away from any water sources.

If you’re making field repairs or your shop has hay or other combustible material on the floor, it’s a good idea to wet it down or lay down a special welding blanket before welding.

While not exactly life threatening, burns from sparks, spatter or chipped slag are still far from fun, and arc flash from insufficient eye protection feels like sand in the eyes or can even blind you temporarily. Appropriate safety apparel should be worn at all times.

Know when not to Weld

Last but not least, there are also times when it just isn’t practical to repair the part with a welder.

“Some hard facing repairs, such as a skid plate on a haybine, will cost more for the box of electrodes than it would cost to buy a new skid plate,” explains Ort. “Hardfacing it would definitely help the part last longer, but it can get expensive, even when you do it yourself.”

While no one wants to need a welder, particularly during the long days of the planting season, the reality is that metal does wear out and crack and being able to repair your own equipment can save you time and money compared to hiring a weld shop to perform the repair. Although you’re likely to find yourself back in the shop with new cracks and holes next season, following these few simple guidelines should ensure that it won’t be because of the same cracks and holes you tried fixing this year.

Published: April 1, 2008
Updated: October 25, 2018