by Jason Becker
Stick Welding, or as it is more commonly referred to as Shielded Metal Arc Welding (SMAW) is one of the oldest forms of welding still in use today. It is often said that Stick welding is the hardest welding process for beginners to learn. I must say that I completely agree.
It requires the most skill, patience, focus and technique to master. I have always told my welding students that I teach stick first, if you can master stick welding, you will have no problem learning the other processes.
By breaking SMAW down into 5 basic steps we can gain a better understanding of the process. By understanding the process and the variables of what effects produce a good stick weld, we can make better welds.
Remember the acronym CLAMS which stands for Current, Length of the Arc, Angle, Manipulation and Speed. These are the driving factors behind a successful weld utilizing the SMAW process. These variables also transfer into other welding processes. By understanding CLAMS and applying them to your welding, you will be able to reliably produce sound welds in many processes.
Starting out with the appropriate current is probably the single most important variable to producing a sound weld. The most common problem new welders face when starting out is the rod sticking to the plate. We have all been there. By selecting the correct amperage, we can help to prevent sticking the electrode. Additionally, if our amperage is set too low we run the risk of not getting adequate penetration into the base metal and the weld not wetting in at the toes of the base metal.
On the other hand, if we set the amperage too high, we can experience a weld puddle that is too wide and too fluid. A puddle that is too fluid is very difficult to control. We also run the risk of developing undercut along the toes of the weld and excessive spatter. Excessive amperage can also cook different elements out of the flux coating of the electrode and ultimately change the characteristics of the electrode entirely.
When we use the appropriate amperage, we find that the weld flows smoothly and we do not get discontinuities related improper amperage.
Many manufacturers of electrodes typically give a wide range of acceptable amperage for each of their electrodes. For instance, one electrode manufacturer recommends their 1/8” E7018 electrode to be ran between 90-160 amps. That is a 70-amp difference. Granted the electrode will run pretty decent at any of those amperages but, we are looking for optimal results.
A good rule of thumb to find a good starting amperage for low-hydrogen electrodes is to use the decimal equivalent for diameter of the electrode. For instance, if we are using a 1/8 E7018 we can take 1 and divide it by 8 which will give us .125 so we will use 125 amps as a good place to start.
Similarly, a 3/32” E7018 would have a decimal equivalent of .093 so we would use 93-amps as a good place to start.
Length of the Arc
Once we strike the electrode against the material, we have to make sure we have the appropriate arc length. A great technique for this is to keep your arc length no longer than the distance of the diameter of your electrode. If you are using an 1/8” electrode, keep your arc length no further away than 1/8” the same rule applies for any other diameter of electrode you may be using.
If the arc length is too short, you run the risk of sticking the electrode, and that’s no fun. If the arc length is too long, you run the risk of the arc extinguishing, excessive weld spatter, and even undercut. As the arc length increases, so does voltage.
When this happens, the puddle gets wider than needed and the edges of the extended arc cut into the base metal and erode the sides of the puddle creating undercut. With the electrode so far away, the inner core cannot fill in with the base metal to fill the eroded edges. I like to keep as tight an arc as possible especially when getting out of position.
When it comes to welding, angles make a huge impact on the outcome of your weld. The two main angles you really need to pay attention to are travel angel and work angle. First let’s discuss the travel angle. With stick electrodes, we want to drag the rod in the direction we are welding. With the tip of the electrode touching the base metal, we need to angle the opposite end of the electrode at 20°-30° in the direction of travel. This will ensure we are getting a fluid puddle, and good penetration into the base metal. If the travel angle is ,less than 20° we run the risk of creating weld spatter (buckshot) due to the energy at the tip of the electrode causing a disruption in the puddle. Once we start passing the 30° angle we start running the risk of decreasing the weld penetration into the base metal.
The second angle we need to focus on is work angle. The work angle is going to dictate the placement of the weld. We want to ensure that the weld ties in exactly where we anticipate it to be.
For a bead on plate or butt-weld, we want to ensure the work angle is 90° perpendicular to the plate. For any fillet welds, you will want to use a work angel of 45°, this will ensure that you get an even bead placement between the two pieces of material.
For multi-pass welds you will want to bisect the toe of the previous weld with the electrode to ensure 50% coverage on the previous weld and 50% tie-in to the base metal.
While welding in the flat position, you typically will not need much manipulation if any. You really want to keep the manipulation within 1-1/2 to 2 times the diameter of the electrode. Most of the time you can just do a slow steady pull across the base metal and the electrode will do all of the work for you as long as the correct travel and work angle are maintained. If you are welding in the vertical position, a slight oscillation is typically used, each welder has their own preference, some move side to side, some make a Z pattern overlapping the weld pool each time they come across. I prefer a U-shaped movement and keep the pool ¼” of an inch in size. Whichever technique you decide to use, keep your focus on the sides of the weld. I tend to hold for a split second on each side and move quickly through the middle of the joint. Because you are working against gravity, the center of the weld will take care of itself. Moving too slow through the middle will cause excessive build-up in the center of the joint.
The last thing we will discuss is speed. To develop a good speed, strike the electrode and establish the arc, pause slightly to give the puddle time to develop. Once the puddle has reached the desired size, maintain a slow steady pull across the joint maintaining the same puddle diameter throughout. You will know if you are going too slow because the weld will become wider and start to build-up higher than needed. Moving too slow will cause a larger weld with shallower weld penetration. It is better to use multiple welds for areas requiring more fill than to travel slowly and make a wider pass.
If you are traveling too fast, then the weld puddle will become narrower than the anticipated side. The weld will also develop a higher crown because the electrode will not have sufficient time to melt in with the base metal. Traveling too fast will result in a high ropey bead profile, lack of fusion along the toes of the weld, little to no penetration, and overlap. All of which you want to avoid to produce a sound weld.
If you are just learning, measure out your plate into 1” segments and draw lines with a soap stone, it should take about 5-6 seconds to get from one line to the next as you are traveling down the joint. Count it out in your head as you go. Eventually you will be able to go off of site, sound and muscle memory.
By utilizing the techniques listed above, you will be well on your way to becoming proficient with the SMAW process. The key to developing the necessary skills is practice, practice and practice. Welding is not an easy skill to learn and will take a lot of patience to master. Go in with a clear head and relaxed, don’t get tense when welding. You want to remain calm cool and collective with each weld. If you make a mistake (and you will) just relax. Analyze what caused the mistake and use that information to prevent it from happening again. You want to evaluate each weld and ask yourself, what went right, and what went wrong. Then use that information and apply what you’ve learned to the next pass. Thanks for reading and until next time, Make Every Weld Better Than Your Last.