When upgrading welders, which is better?
Welding has advanced since the 1930s, when stick (electrode) welders, using an AC power source, began making their way to farm country. Today there are other options, such as TIG and wire welding, but stick welders remain the go-to form of welding to tackle many farm tasks. Here are several tips from experts to help you use your stick welder more effectively.
Because farm equipment manufacturers use metal inert gas (MIG) welders to assemble machinery, many farmers assume a MIG welder is the optimum welder for a farm shop.
However, experts say that an A/C or A/C-D/C welder that uses stick-type electrodes might be a better choice.
"For general repair and maintenance work, where you’re going to be welding rusty or painted metal, maybe outdoors in the wind, stick [welding] is a better process," says John Leisner of Miller Electric Mfg. Company. "MIG is good for fabrication, where the metal is clean, unpainted and the environment is wind-free."
MIG welders produce beautiful, liquid-looking, spatter-free welds, but require stringent conditions. Metals at the weld point must be completely free of corrosion and paint. Ground clamps must be attached as close to the weld point as possible. Any wind (even the breeze from a shop fan)can disrupt the shield of inert gas around the welding arc and create weak, ugly welds.
"Metal preparation is always recommended for any welding process, but with stick welders you can weld rusty painted metal outdoors in the wind with good results," Leisner says. "You can connect your ground clamp to the machine 20' from where you’re welding and still get a good arc. I’d say 80% of the time, stick welders are a better fit for farm use [than MIG welders]."
The downfall with stick welders is welding thin metal. Conventional A/C stick welders tend to "burn through" when welding metals thinner than 1⁄8", while MIG welders can weld metal as thin as 24 gauge (0.0239").
Dan Klingman, a technical trainer with Lincoln Electric, says using a stick welder with a direct current (D/C) option can reduce "burn-through" when welding thin metals.
"You can use straight- or reverse-polarity on a D/C welder, which changes the direction of flow of electricity. Straight-polarity reduces the tendency to ‘burn through’ when you’re welding thin metals," Klingman says.
Farmers who try a modern A/C-D/C stick welder are often surprised. "Somebody who goes from the welder their grandpa bought 30 years ago to a new welder will notice a big difference," Klingman says. "The new electronics make it a lot easier to strike an arc, and they produce a smoother arc that minimizes spatter."
Chad Schincke of Dakota Dunes, S.D., won a trip to the 2009 Miller Welding University, hosted by Farm Journal and Miller Electric Mfg. Co., and noted the advantages of welders equipped with modern technology.
"Compared to the old A/C welder that I was used to at home, the newer welders seemed to have more power. They didn’t stick all the time when I was trying to start an arc, and it was easier to maintain an arc while I was welding," Schincke says. "That made it easier to do vertical and out-of-position welds that I wasn’t really comfortable with when I used our old welder."
Alternate options for MIG. While stick welders are the most versatile welders for farm use, there is an option that makes MIG welders more flexible under farm conditions. Converting to flux-cored wire can increase a MIG welder’s ability to weld painted, corroded metals outdoors in the wind.
Conventional MIG welders use an inert gas to shield the arc from atmospheric gases that contaminate welds and create uneven, bubbly welds. Flux-cored wire has shielding flux inside the wire. The flux vaporizes in the heat of the welding arc to shield the arc from atmospheric contamination.
"You have to change the spool of wire from regular MIG wire to flux-cored wire, and you absolutely have to reverse the lead connections inside the welder to reverse polarity, but flux-cored wire is a way to make a wire welder work well under field conditions," says Scott Rozmarynowski of Hobart Welding Products.
"Flux-cored welds have to be chipped and cleaned like stick welds, but flux-cored welding is more forgiving [than MIG welding]," he adds.
"Flux-cored wire welding is an option somewhere between stick and MIG," Rozmarynowski explains. "MIG is hard to beat for welding clean metal under controlled conditions, but stick welders are still probably best for all-round farm use."
Pros and Cons of MIG and Stick Welding
Metal Inert Gas (MIG) Wire Welding
- can weld metal as thin as 24 gauge (0.0239")
- produces beautiful, smooth, slag-free, nearly spatter-free welds
- welding is never interrupted by the need to stop working in order to replace the electrode (stick)
- even a minimal amount of rust, paint or contamination can create porous weak welds
- ground clamp must be on bare metal and must be near welding point.
- any breeze, even a shop fan, can disrupt shielding gas and result in porous weak welds
- pressurized bottles of inert gas necessary for MIG welding are clumsy for field repairs
- must change entire spool of wire to weld special metals—aluminum, cast, etc.
A/C or A/C-D/C Stick Welding
- less sensitive to paint and corrosion at welding point
- ground clamp can be attached far from welding point
- not affected by wind
- easy to change rods to weld special metals—cast, stainless, etc.
- welders with direct current (D/C) option can alter polarity of electrode to reduce burn-through in thinner metals
- the slag must be chipped from the welds prior to painting or subsequent welding
- some spatter is inevitable; D/C stick welding has less spatter than A/C welding
- welding is interrupted every time a welding rod must be replaced
- welding metal less than 1⁄8" thick is difficult