A Guide to Hot Start, Arc Force, and Anti Stick in Stick Welding
Welding technology advances and more inverter stick welders come with the hot start, arc force, and anti stick features. These features are beneficial for both beginners and more experienced stick welders.
This article explains each one and how they help make stick welding (SMAW) more comfortable and productive.
Table of Contents
- What is hot start in welding?
- What is arc force (or dig) in welding?
- What is anti stick in welding?
- Conclusion
What is hot start in welding?
Hot start is a feature that pumps up the amperage for a short time when you start the arc. Higher amperage helps to start the arc easier without sticking the electrode to the base metal. Hot start also helps to warm the base metal fast to achieve deep penetration at the bead’s starting point.
Difficult arc striking, sticking the rod, and low penetration occur when striking the arc. These happen because the electrode and the base metal have low temperatures.
These “cold starting” problems are more noticeable on the first arc strike because everything is at room temperature.
Without hot start, you must use special electrode (or rod) manipulation to achieve the same results.
Some other cases where hot start helps
Hot start helps when you weld with rods that are hard to start, such as the low-hydrogen E7018 rod.
When rods are left unprotected, the flux is affected by the air’s moisture. When the flux has excess moisture, it is slightly harder to strike the arc. Moisture contamination is more critical with low-hydrogen rods, especially if they weren’t stored in a welding rod oven.
Hot start also helps when the base metal is not very clean. Surfaces with mill scale or rust, resist electricity but also make the puddle less fluid.
How to use hot start?
You set hot start on most welders with LCD screens as a percentage of the amperage you want to weld.
- Set this percentage initially to 120% or by the welder’s default setting if there is one. Some stick welders might have a range of 0-10. If so, then set this to 2.
- Some, but not all stick welders, have a time duration for the hot start, set it to 0.5 seconds.
- Weld with these settings on scrap metal and tweak them if necessary.
When the settings are satisfactory, and you can start the arc with low effort, weld your project.
What is arc force (or dig) in welding?
Arc force (or dig) is a feature that senses the drop of the arc’s voltage caused by arc length shortening. Arc force compensates for the voltage drop by increasing the amperage. Increased amperage ensures that the heat stays the same and that the electrode will not stick to the base metal.
When stick welding, it is vital to maintain a steady arc length all the time. The arc length must not be longer than the rod’s diameter.
However, keeping a steady arc length is not easy. A new welder might not have enough experience or might not have steady hands.
If the arc length shortens for whatever reason, the arc’s voltage decreases too, but the amperage stays almost the same.
Despite that the amperage stays about the same, the puddle’s heat (volts*amps) will drop.
As a result, the arc extinguishes, and the electrode sticks to the base metal resulting in frustration.
Sticking the rod is one of the most common stick welding problems, and by many, where its name come from.
Arc force detects the arc length shortening and increases the amperage to keep the heat high enough to maintain the arc and prevent sticking the rod.
Some stick welders might mention arc force as dig or arc control.
Some other cases where arc force helps
Arc force is especially useful for welding in vertical and overhead positions because keeping a short arc is even more important.
Electrodes that have excess moisture or light cracks in the flux will tend to stick. Arc force offers a stronger arc and helps if you want to weld with these rods.
How to use arc force?
Depending on the stick welder, you set arc force as a percentage or a range between 0-10. The higher you set it, the more intense the effect will be.
Cellulosic rods such as the E6010 work better with a higher arc force setting of 60% or more. A high arc force value creates an aggressive arc, also called a crisp arc.
Low-hydrogen rods such as the E7018 work better with a lower arc force setting of 30%. A lower arc force value creates a smoother arc, also called a soft or buttery arc.
Expensive stick welders with an LCD screen have preset arc force settings for each rod type. These settings are a good starting point.
Test the arc force settings on similar scrap metal until they are satisfactory.
When not to use arc force?
One possible side effect of welding with arc force is that the temporary amperage boost may burn through thin metals.
Another drawback of arc force is when welders want to control the puddle’s heat the traditional way.
For many welding situations, welders want to decrease the puddle’s heat when shortening the arc or increasing the heat by lengthening the arc. Arc force will work against this since it auto-adjusts the amperage.
What is the dig function?
Dig is the same thing as arc force. Sometimes welders use this term to describe the intentional usage of arc force from the bead’s start until the bead’s end. This is done on purpose to ‘dig’ deeper into the workpiece and not just to autocorrect an accidental shortening of the arc length.
For more demanding work, for example, when welding in the overhead position, you want to keep a very short arc length for all the bead’s length.
At the same time, enough amperage must be present to maintain the arc and achieve deep penetration.
Keeping a very short arc length all the time is very hard, and there is no room for error. Arc force or “dig” ensures adequate amperage for the entire bead’s length.
What is anti stick in welding?
Anti stick is a feature that will take action when the electrode sticks to the base metal. It will detect the short circuit and automatically cut the current. This prevents the electrode from turning red-hot and the welding machine from overloading. The anti stick feature is embedded in the welder. There is no control to set it.
If your stick welder doesn’t support anti stick, you want to act fast and twist the rod off with some left and right movement to break it free.
If the rod is permanently stuck, you can press the release lever on the electrode holder to release it. Keep in mind that there will be some sparks. Leave the rod on the metal to cool for a little while, and then remove it.
Finally, you can turn off the welder, but don’t pull the plug. The welder’s fan needs to work until it cools down.
Keep in mind that many affordable stick welders mention that they support hot start and arc force, but what they do is embed them with preset values. These welders don’t have dedicated controls to set the values yourself.
Conclusion
Hot start, arc force, and anti stick are modern features of inverter stick welders. All of them help against one of the disadvantages of stick welding, which is sticking the electrode.
- Hot start increases the amperage when striking an arc.
- Arc force increases the amperage when shortening the arc length.
- Anti stick cuts off the current when the rod sticks to the base metal.
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