In this video, I tested the PrimeWeld MIG180 recommended settings for 11ga steel and then also tried those same settings on 1/4" thick carbon steel.
I used the pigtail adapter and plugged into my garage 115volt wall plug and I was so impressed that I immediately added this welder to my store at weldmonger.com
The Term "Short Circuit" sounds weird doesn’t it? I mean when something short circuits, that’s usually bad. Right?
Well when it comes to mig welding , the term “short circuit” is just a mode of metal transfer where the wire short circuits while it melts into the molten puddle.
While the wire is short circuiting, amperage builds to the point where the wire melts back and creates a monetary arc that provides the heat.
This short circuiting and arcing happens somewhere around 90-200 times per second depending on settings used.
This article and video are strictly about short circuit mig welding but we have to at least have a basic understanding of the other modes of mig welding in order to avoid confusion.
There is another version of the mig welding process called Spray transfer mig. Aka spray mig.
Spray transfer is where much higher settings are used along with a different gas mix to achieve a very hot arc where instead of the wire short circuiting to melt into the puddle, fine droplets of molten metal spray into the puddle.
Short circuit mig welding is used on anything from thin auto body panels, to medium duty fabrication.
Spray transfer is too hot for something as thin as auto body sheet metal and is used more for hot production welds like railroad box cars.
There is a third version of mig welding called globular transfer that is sort of what happens when settings are too high for short circuit.
Globular transfer is sometimes used intentionally but also sometimes just happens when voltage and wire speed settings too high for short circuit transfer or when someone is trying to achieve spray transfer with the wrong shielding gas.
Think of it like this...
Consumer mig welding machines that you might see in big box stores like Home Depot, Lowes, or tractor supply, are made for short circuit mig welding. (and flux core)
While large industrial machines with 300 amps or higher ranges are made for spray transfer but can also do short circuit mig.
What is short circuit MIG used for?
Because short circuit mig welding has a lower heat input than spray transfer mig, its an all position process that lends itself well to general fabrication, open root passes in pipe, and motorsports chassis welding where wall thickness is usually under 1/4” .
Short circuit mig welding is considered a light duty welding process and because of a tendency for lack of fusion on thicker metals, is discouraged for thicker structural welds in welding codes like AWS D1.1
Did you know that when you use a longer stick out, your amperage actually drops?
Thats why I prefer to use a short stick out with short circuit mig welding. I notice less spatter, a crisper arc, and the puddle is noticeably hotter.
Some contact tip and nozzle setups have the contact tip recessed a bit more than I like for short circuit mig welding.
A recessed tip works great for spray transfer mig, but I'm not going to be doing any spray with this welder.
I prefer the tip to be flush for short circuit mig so I trimmed about 1/8" off with a grinder.
What weld defect is most common with short circuit MIG?
The most commonly seen weld defect with short circuit mig is lack of fusion. Especially when mill scale coatings are not removed prior to welding or when welding downhill.
What is the difference between short circuit and spray welding?
The term “short circuit” is just a mode of metal transfer where the wire short circuits into the molten puddle.
This happens somewhere around 90-200 times per second depending on settings used.
Spray transfer is where much higher settings are used along with a different gas to achieve a very hot arc where instead of the wire short circuiting to melt into the puddle, fine droplets of molten metal spray into the puddle.
What are the 3 types of MIG welding?