What About GMAW and FCAW? Nothing on These Processes?

Some of you are probably wondering why in the hell I have not mentioned GMAW/MIG - Gas Metal Arc Welding and how to teach that process to high school students and the closely related Flux Cored Arc Welding process. I am not trying to down play the the value of GMAW and FCAW I just don't put a lot of time into teaching GMAW/FCAW and this is my theory as to why I go that direction. 

What you say? Surely the Great and Powerful OZ must have a long winded in depth 10,000 word dissertation stashed away that explains the everything in painful excruciating detail on how to teach high school students to wire feed weld with GMAW or FCAW.  Nope I got this one covered in about 1000 words plus or minus.


I hate to disappoint anyone reading this blog post, but sadly I don't have a lot to say on this subject other than I fully realize that both of these welding processes are extremely valuable in industry, and are used a lot.  Their value is due to the higher deposition rates and the greater productivity that comes with these processes compared with SMAW/"Stick Welding. That being said in my opinion it is much more difficult to teach someone to "Stick Weld" than it is to teach someone to  wire feed weld using GMAW or FCAW, so I don't focus on  teaching these welding processes other than the academic side. 

This is not to say that my students didn't learn anything about GMAW or FCAW. Towards the end of the school year usually in April and May my students would cycle though the few weld booths that were set up for GMAW. And the response from all of the students was - "That is so easy." And my reply was - "Does it make sense why we don't focus on teaching MIG welding?"

In my opinion if a student can Stick Weld it will take them about 20 minutes to figure out how to wire feed weld. That is the crux of my theory on teaching GMAW/FCAW welding. My basic theory is to teach Stick Welding - going heavy on the Stick welding instruction and do a little bit of wire feed welding with the students, let them pull the trigger weld a little bit and call it good. Time to get back to perfecting stick welding.

On the academic side I do go much deeper into the parts of the process including the guns, liners, contact tips, wire feed rolls, shielding gases and the general theory of how the GMAW and FCAW processes work. I spend more time showing the students how to take apart the welding guns replace consumable parts like the tips, diffusers liners etc. than I do showing the students how to use these welding processes to deposit weld metal in a joint. 


What part of a typical welding gun is shown in the picture?

a - Diffuser

*b -Nozzle

c - Liner

d- Contact tip

With questions like the one shown above I really try to focus GMAW instruction on the parts, pieces and process side of welding. Getting the students familiar with the parts of the welding gun, what the different transfer modes are, machine and gun maintenance etc. I do this because even thought the skill set to deposit sound weld metal is not as great as it is with GTAW or SMAW (Stick) the knowledge needed to get a GMAW machine up and running when things go sideways is much greater. For GMAW the welder has to assume the duties of repair mechanic just in case there is an issue with the welding machine.

I also go heavy into the different transfer modes for GMAW - I explain the differences between short circuiting transfer mode, globular transfer mode, spray transfer mode and pulse spray transfer mode. This might seem like overkill for high school students but I think if they hear it over and over for three years it does eventually sink in.


What type of GMAW welding occurs when relatively low welding currents are used. It also used electrodes wire sizes under .045"?

a - Spray Transfer
b - Pulsed Spray
c - Globular Transfer
*d - Short circuiting

Another crucial component that I work into the GMAW lessons is welding defects, especially overlap, cracking and porosity.


Moisture, rust and dirt on the surface of the welding wire/electrode is likely to cause:
 a - cold lap.
 b - Undercut
 c - slag inclusions
 d - Porosity.

As explained in a previous rant - I think that it is very important that the people teaching welding use technical vocabulary with the students and keep reinforcing that vocabulary. Especially in the form of 8 or 10 question quizzes, this use of repetition helps the student build a technical welding vocabulary that will be of use later on. 

So that pretty much sums up in about 1000 words my theory on teaching Gas Metal Arc Welding. Those 1000 or so words pretty much cover my whole belief system on GMAW. Teach SMAW and hit that hard - give the students some GMAW/FCAW practice with a ton of academic work in those processes and then call it good. Because if the students are proficient with stick welding they will figure out GMAW/FCAW pretty quickly.

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