Reverse Polarity or Straight Polarity? Which one is in your wallet
When welding with the SMAW process, it is a good idea to have an understanding of what type of polarity is best suited for the electrode you are using. There are three types of choices we can have, depending on the machine, which should be based on the choice of electrode we are using. These three are Reverse Polarity, Straight Polarity, and Alternating Current.
With the first two (DCRP and DCSP) they are only available as a choice if we are using Direct Current. Alternating Current is a stand alone choice because the polarities are alternating between DCRP and DCSP at 60 hertz.
SMAW machines come in forms of:
1. A/C machines only
2. DC machines only
3. A/C DC machines
The A/C only machines are usually the cheaper of the three in terms of cost to buy. They typically produce current outputs for welding up to 225 amps. The DC only machines are more expensive to purchase simply because of the rectification needed to convert A/C input power to DC output. They produce welding currents similar to A/C but sometimes less output at the upper range. The A/C DC machines typically have higher AC welding currents. They are also common with most upper-end GTAW machines. Remember both SMAW and GTAW share the same type of power source (Constant Current).
Anyway, while you are in the DC mode, you can choose to either weld in Reverse or Straight polarity. What am I talking about?
Electrons naturally travel from the negative terminal of a DC power source (Battery, welding machine) to the positive terminal. By changing the orientation of what our electrode is hooked up to verses our work, we get different responses from the electrodes. Reverse Polarity can be thought of as “Electrode Positive” and Straight Polarity can be thought of as “Electrode Negative”. Most electrodes these days state that they can be used in either polarity including A/C. However, they do respond better to the polarity they were designed to be used in. Why do the electrode manufacturers state they can be used on both polarities and A/C? Whereas, in the past, the containers specifically stated the preferred type of polarity. I don’t know and I don’t like it. I will give you the best polarities for a few electrodes. They are:
1. E6010- Reverse Polarity
2. E7018 – Reverse Polarity
3. E6011- A/C
4. E6013 – Straight Polarity
5. E7024 – Straight polarity
Much more will be said concerning this but I will save that for part 2