Polarity: When should it be reversed? Part 1
Any one that has been around welding for a short period of time knows a little about the term "Polarity".But quite a few new comers find the correct use of polarity a confusing issue, though it need not be. A lot has been written on the internet about polarity, and this blog will undoubtedly add to that information. But, hopefully it’ll be easier to understand than some of the other ponderous articles written about it.
Polarity is simply a term to describe the whether the electrode is a cathode or anode. Quite simply it refers to whether the electrode is emitting (negative polarity) or receiving electrons (positive polarity). These terms are related to DC welders only. Welders that output AC current have no need to refer to polarity. So if you are welding with an old AC buzz box welder, polarity is of no consequence to you. But if you are welding with new inverter welder, or even an old DC transformer welder, it is. Sometimes you may see the terms DCEP or DCEN. These refer to Direct Current, Electrode Positive, or Direct Current Electrode Negative. Polarity is always marked on a DC welder and will usually bear a simple negative (-) or positive (+) sign. Whenever a polarity change is required, the electrode (sometimes referred to as a torch) should be inserted into the side with the marking that corresponds to the polarity recommended.
Simple huh? Well, not that simple. A lot of old texts and "old school" welders will often refer to the terms of "Straight Polarity" and "Reverse Polarity". Straight polarity refers to negative polarity. Reverse polarity refers to positive polarity. While that may seem to make sense, if you think about electrons always flowing from negative to positive poles, it is confusing when it is applied to several different welding processes such as stick and MIG welding.