Short circuit MIG doesn’t Fail people. People Fail Short Circuit MIG

Short circuit MIG doesn’t fail people.

People fail the process by using cold settings just for appearance sake..and by not recognizing it's limitations.

1. The Real Problem is not Short Circuit MIG

Short circuit MIG is:

Easy to use
Very versatile
Easy to control the puddle out of position
But also very easy to misuse

The danger is this:

There is nothing in the process itself that forces the welder to use enough heat.

For example, for 3/8” thickness, settings should be around 23-24 volts with 450-500 inches per minute of wire speed (using .035” diameter wire)

If you use these settings along with a short CTWD (contact tip to work distance) and weld on clean metal that is free from heavy mill scale, you can achieve good penetration on a 3/8" fillet weld .

And on a 3/8" vertical UPHILL fillet weld, you can get penetration with slightly lower settings,

But for some reason, a lot of folks just won’t use those settings.

For a sake of a prettier weld… Some Folks:

Turn the wire speed and voltage down really low
And often still get a nice looking weld that passes visual inspection
But visual inspection can only detect what is on the surface``

What’s underneath?

A weld made with cold settings can be fused in at the toes with hardly any penetration underneath

So the real issue is:

Short circuit MIG allows you to make welds that look good even when they’re structurally BAD.

2. Why This Happens

As you turn settings lower/colder:

The arc gets weaker
The puddle gets calmer
The bead gets smoother
The weld often gets prettier

But at the same time:

Penetration suffers
Fusion suffers
Lack-of-fusion defects increase
Mill scale becomes a real barrier to fusion
And the weld becomes decorative instead of structural

Cold settings sacrifice strength for appearance

3. Why This Is Especially Dangerous on Thick Material

Once you get to about 3/8" thick and up, a few things change:

The base metal becomes much more of a heat sink
Mill scale is usually thicker on thicker metal
You need real energy to get fusion at the root and sidewalls of a fillet weld
You need arc force and fluidity, not just wire melting off into caulk beads.

4. How Spray Transfer MIG differs from short circuit

Spray transfer requires an argon rich gas mix. (90/10 and 95/5 argon/co2 are two common mixes for spray).

Here’s the beautiful thing about spray transfer:

You cannot run spray transfer cold.

Spray transfer:

Requires a minimum voltage and current to even exist
Produces a high-energy, stiff, driving arc
Literally forces heat into the joint

If you’re in true spray transfer:

You are already above the cold-weld zone
You are already putting in serious energy
You are already getting deep fusion and penetration

So spray transfer acts like:

A built-in protection against cold welding.

You might still mess up technique — but you won’t accidentally be too cold.

The down side to spray transfer is that it is too hot for vertical uphill welding,

That is where pulsed spray mig comes in.

5. Why Pulsed Spray can be a Better choice (In Many Shops)

Pulsed spray gives you:

Spray-level fusion and penetration
But with:

Less average heat input
Less spatter
More control
Better out-of-position capability

Pulsed spray gives you the benefits of spray with the puddle control of short circuit.

But there is a downside: pulse spray requires a machine with pulse spray capability. Whereas spray transfer simply requires the amperage and duty cycle range.

And that is why dual shield flux core can be an excellent choice for some shops.

Dual shield flux core is also called FCAW-G

(Flux-Cored Arc Welding - Gas Shielded)

Dual shield flux core does not require a special mig machine. Almost any mig welding machine that has enough power and duty cycle can be used.

Dual shield flux core uses the same shielding gas used for short circuit mig 75/25 argon/co2 (or pure co2.)

Because it uses flux as well as shielding gas, dual shield does a great job penetrating thru mill scale.

Dual Shield provides characteristics similar to solid wire MIG spray transfer but with the added benefits of flux for strength and quality.

Dual shield flux core is often used for thick steel in several different industries like construction and shipbuilding.

Dual shield flux core wire is available diameters as small as .035” that allows it to be used on small portable mig welders which gives a lot of options to small welding shops.

6. The Bottom-Line Rules of Thumb

Short circuit MIG is a light to medium general fab process.
Spray , pulsed spray, and dual shield flux core are production and structural processes.

When the steel gets over 3/8” thick:

You don’t need prettier. You need good fusion.

Take us up on our FREE welding guides