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5 things you need to know about modern stick welding

Shielded metal arc welding still plays an important role in metal fabricating

Figure 1
Author Jay Ginder demonstrates modern stick welding at a training event for ironworkers in Ann Arbor, Mich., this past summer.

If it were up to the manufacturing consultants of the world, all welding processes would be automated. Computer programs would guide the robot during the welding process, and other robots would handle part presentation and assembly removal after welding. Welding would be neat, organized, and predictable.

For the most part, however, consultants don’t spend every day in the real world of welding. A fabricator, for example, requires flexibility and portability in some cases. That’s the simple reason that shielded metal arc welding (SMAW), or stick welding, is still relevant for thousands of metal fabricators that work in heavy fabricating facilities, structural steel shops, shipyards, and in the field. That’s saying something for a process that dates back to the 1890s when the first U.S. patent was issued for the use of an electric arc to melt an electrode and have the molten metal fill an open joint.

In some ways, the SMAW process hasn’t changed much over the decades. A welder still strikes an arc to get the process started and lays a bead with the melting electrode. That power source and electrode, however, have changed pretty dramatically over the years (see Figure 1). Here are five things you need to know about modern stick welding if you haven’t worked with the process in years or are new or unfamiliar with it.

1. The power source used for industrial SMAW is very different from a small buzz box available at the nearby big-box store.

If you are involved in SMAW, you are going to be using a constant-current machine. Odds are, however, that the machine is going to be capable of a whole lot more (see Figure 2).

The power source is likely to be based on inverter technology, in which the unit is able to take the AC power from the power lines coming into the shop; change it to DC; and invert the DC power into a stepdown transformer, which allows the welder to dial in specific welding voltages and current. Traditional transformer-type power sources, which might still be used in some places, have been eschewed in favor of inverter technology. The inverter units are much more portable, and it’s very easy to put six to 10 machines on a rack for field work.

Today’s inverter technology allows a power source to run on 220 or 110 volts and switch between single- and three-phase power. Some more traditional units may allow for changing the voltage, but not the phase.

This type of industrial unit has much more power than a welder typically needs to run the SMAW process. Because the inverter power source can run multiple processes, the welder probably will have a unit in the 300- to 400-amp range. This is particularly helpful if the welder needs to do the occasional carbon arc gouging, for example. In reality, a welder who is using 5⁄32-inch-diameter or smaller electrodes on a regular basis needs only about 250 amps for most work.

These industrial units are designed to run for long periods of time as well. In a field test, two stingers with 5⁄32-in. 7025 low-hydrogen electrodes were connected to one of these modern multiprocess power sources, and two welders continuously put down bead after bead on a 2-foot-long plate until about 36 electrodes were consumed over nearly 25 minutes. As any welder knows, stopping in the middle of laying down a bead is never a good thing, but with modern inverter technology, a stick welder doesn’t have to worry about stopping because the power source is overheating.

2. Modern power sources have technological enhancements aimed at helping stick welders.

SMAW power sources don’t grab the headlines with frequent technology advancements like those associated with gas metal arc welding, but that doesn’t mean that today’s power sources are the same as boxes from 25 years ago.

For example, modern SMAW power sources can help even experienced welders from sticking an electrode. When does this happen? If a stick welder has ever applied pressure to an electrode and tried to force metal into the back side of a joint, he has probably stuck an electrode to the metal. The scenario is pretty simple to understand: As the electrode gets close to the metal, the voltage drops, the arc stops, and the electrode sticks in the solidified weld pool. Modern SMAW power sources are equipped with “intelligence” so that they recognize when the electrode is getting close to the metal. At this point, the power source raises the current, so the electrode doesn’t stick. Of course, this type of programming is not utilized all the time, but it is a good example of how power sources have improved to assist stick welders in difficult applications.

Figure 2
A modern SMAW power source has a display that is similar to that found on a tablet or smartphone. It provides very specific operating instructions, such as parameter recommendations, and can even be used to access the unit’s parts manual.

In another example, SMAW power sources can be set so that striking an arc doesn’t result in a big knot at the beginning of the weld. This type of “hot start” function increases the welding current for an adjustable time at the start of the weld, which reduces the risk of poor fusion when beginning the weld.

3. Today’s electrodes are more moisture-resistant when compared to electrodes used 10 years ago.

Hydrogen cracking used to be a real concern for stick welders. Earlier generations of electrodes released hydrogen at a greater rate than those of today, which contributed to cracking at the joint at a later time. Cracks in ship hulls were a particular problem in the middle of the 20th century.

The debut of low-hydrogen electrodes meant that cracking was less of a concern for welders, but it also posed a storage dilemma. If exposed to general atmospheric conditions where they can pick up moisture once their hermetically sealed containers are opened, these electrodes could introduce hydrogen-induced cracking to the joint. These low-hydrogen electrodes needed to be used quickly or stored in an oven at a temperature around 250 to 300 degrees F.

Now these electrodes can be exposed to general atmospheric conditions for up to nine hours without too much worry of introducing too much hydrogen to a weld. They go by the designation of E7018 H4R (see Figure 3). (“E” stands for electrode. “70” means the electrode meets minimum tensile strength requirements of at least 70,000 PSI. “1” indicates that it is designed for flat, overhead, vertical, or horizontal welding. “8” indicates the electrode’s has an iron-powder, low-hydrogen coating and should be used with DCEP. “H4” denotes that the maximum diffusible hydrogen limit is 4 mL per 100 grams. “R” means that the electrode meets the minimum requirements of the absorbed moisture test.)

Stick welders used to a traditional premium 7018 electrode will find that E7018 H4R electrodes offer similar performance. Engineers, however, find the evolution noteworthy because they can specify this type of electrode for jobs in which properly storing electrodes and keeping track of just how long low-hydrogen electrodes have been exposed to the environment can be tricky; if the electrode can be exposed for nine hours, that’s a full working day for most welders, and no special handling instructions are needed on work orders.

4. Electrodes are tailored to special applications.

It seems like stick welders today might be able to find an electrode for almost any application. Do they need an electrode for military applications where the joint has to demonstrate greater yield strengths than typical welds? Are they working on projects where the workpiece will be stress-relieved for as many as 24 hours? Do they require a special electrode that is compatible with alloys used in some pressure vessel fabrications and has to demonstrate good impact resistance and stand up to low temperatures? There are electrodes for all of those applications.

Electrodes even have been developed to help new stick welders. These electrodes exhibit better stability and arc control, and the burnoff is better when compared to traditional low-hydrogen electrodes. This novice-friendly electrode is especially good for welding out of position because the new welder doesn’t have to manipulate or control the electrode as much. Because the electrode delivers a fast-freezing slag behind the weld puddle, the beginner stick welder can build up the weld more confidently when working in the vertical-up position.

5. SMAW still requires skill.

SMAW equipment and electrodes may be more user-friendly, but a person still needs to have some skills to be an effective stick welder.

Consider a welder using a 6010 electrode in a general repair scenario. The electrode is very aggressive and runs very hot. A welder needs to keep the arc-to-metal distance pretty consistent, because if he creates an arc that is too long, pop-outs can occur. (Pop-outs are when voltage drops, which is the result of an electrode being too far from the base metal.) Pop-outs can create weld defects. The goal is to create a complete weld with no stops and, of course, no pop-outs. That requires a consistent weld movement.

Conventional transformer machines are still widely used, especially in heavy industry. But for portable applications, smaller fab shops, repair use, rental departments, and home use, compact inverters are becoming the norm. Welders of all skill sets owe it to themselves to test-weld with one to experience their advanced performance capabilities.

Figure 3
A low-hydrogen 7018 H4R electrode is used during a stick welding demonstration.

About the Authors

Dwight Myers

Product Business Manager, Filler Metals, North America,

800-372-2123

Jay Ginder

Senior Sales Application Engineer

Filler Metal Manufacturing Center 801 Wilson Ave.

Hanover, PA 17331