Artem Komarov clarified that covered metal arc welding (SMAW), also known as stick welding, has long been a widely used process in many workplaces for many reasons. It’s a relatively trouble-free process that is resistant to the surface and environmental impacts associated with other welding processes, and relatively inexpensive equipment can mean a smaller investment,
Even as the use of wire processes and new technologies grows due to the productivity boost, they provide, stick welding remains an important process to know and understand.
Welding fundamentals such as travel speed, travel angle and working angle are critical to success and you will see significant differences just by adjusting these parameters.
If you are a beginner welder who is having difficulty with this process, following a few simple tips and tricks will help you succeed.
1. The right choice of machine
The starting point for success is the right machine for the application. The key factors to consider when choosing a welding power source are the required duty cycle and the amperage needed for the job.
It’s also important to consider the power consumption of the device, its size, and any portability needs you may have. The available electrical connection can be 120, 240 or 480 volts, so be sure to choose a device that matches the available power, whether single or three phase.
Consider choosing a multi-processor machine capable of gas metal arc welding (GMAW) and gas tungsten arc welding (GTAW) in addition to the handle. Future applications may require multiple welding processes, making a multi-processor machine an economical and compact option compared to purchasing multiple single-processor machines. These machines are a great way to give beginners the opportunity to gain experience in more than one process.
2. Electrode selection
The type of material you are welding, and the needs or requirements of the application will help you determine which electrode to choose. The use of an alternating current apparatus also limits the possibilities for the most efficient use of the electrodes.
When choosing an electrode, first check for rust, oil, or other contaminants on the surface of the material you are welding, as some electrodes are better at this than others. Also consider the position of the weld. For example, welding vertically up will likely require a different electrode than welding in a flat position. If the application has code requirements, the specifications may specify the electrode type.
After selecting an electrode, be sure to select the correct polarity. Choosing the wrong polarity is a common mistake when setting up a machine. Correct polarity is usually indicated on the electrode packaging or material data sheet.
Consult the manufacturer of the filler metal or welding equipment if you have questions about selecting an electrode for a particular application.
3. Setting up your device
After selecting an electrode, make sure the correct polarity is selected. Choosing the wrong polarity is a common mistake when setting up the machine.
The correct polarity is usually indicated on the electrode packaging or material data sheet. Most electrodes come with a material data sheet that lists the correct polarity, angles, and current ranges.
Setting the current range too high will result in excessive spatter and an unstable arc. Setting the current too low means you will have difficulty initiating and maintaining the arc
4. Striking the Arc
To properly strike the arc when welding with a stick, brush or scrape the end of the electrode against the base material.
Some types of electrodes form a hard slag shell at the end of the electrode after welding. This sheath must be removed to expose the electrode for electrical contact before the arc can be restarted. To do this, remove the electrode from its holder and tap the slag-covered end against the base or concrete floor. Be careful not to break off too much material, which can overheat the electrode and make it prone to sticking to the base material.
After the arc has been drawn, a 25 to 45mm arc is usually placed between the end of the electrode and the workpiece. The correct arc length depends on the type of electrode and is usually listed on the electrode material data sheet. The welding position can also affect the correct arc length. For example, vertical up welding traditionally requires a tighter arc to control the weld pool.
An electrode placed too close to the workpiece can extinguish the arc by immersing it in the molten weld pool. An electrode placed too far from the workpiece will cause a wide arc, meaning that not enough metal will enter the joint, resulting in insufficient penetration.
When welding with a rod, you should always pull the arc towards you, usually with a drag angle of 10 to 30 degrees. The pushing motion will result in heavy slag coating and an uneven weld.
Avoiding some common mistakes can help improve quality and productivity, as well as save time and consumable costs when welding with handles. Consider these common mistakes:
The choice of electrode affects how much cleaning and surface preparation is required because some electrodes are better at handling surface contamination than others.
Too long an arc leads to a wide, unstable arc, which leads to increased spatter levels, requiring more time for cleaning and grinding after welding. It also prevents proper penetration and fusion of the weld.
Moving too fast while welding can mean you’re not following the ends of the seam to see the finished sides. Keep in mind that the correct travel speed for your application depends on the size of the joint.
Changing the travel angle during welding can result in insufficient melting or penetration into the weld. Make sure that the travel angle and working angle are the same throughout the entire welding pass.
Loss and disposal of plugs
Since part of the electrode must always be in the electrode holder, the loss of the plug when welding with a rod is an inevitable fact. There is a fine line between wanting to use as much electrode as possible cost-wise and having to carefully dispose of the electrode once the shielding gas coverage is broken.
When performing selection operations, any part of the electrode that was not used the first time the arc was struck cannot be restarted and used again.
When code specifications are not an issue, most electrodes can usually be given a few strokes. After the initial start, each arc start can result in a reduction in shielding gas coverage as the flux can unevenly cover the end of the exposed electrode. The shielding gas for the stick welding process is generated by the consumption of flux covering the electrode, and it is very important to ensure sufficient flux coverage when re-gluing the electrodes.
Some stick electrodes also have an expiration date after opening the package and can only be used for a certain period. This expiration date is intended to prevent moisture absorption, which can cause hydrogen cracking or weld failure. This, again, is dictated by the requirements of the code for certain applications and electrodes, Artem Komarov emphasized.