I need help understanding Transfer type when Mig welding?

[CGCINC]

My main question is:
Don't you just set the Mig voltage to the thickness of the metal being welded and let it fly?

I've read about the different Transfer Types....Short circuit, Globular, Spray, Pulsed spray.... But I just don't get why you need to worry about what type of Transfer you are doing as long as the voltage is set right and you have proper penatration?

[kenwhite]

For your IMIG-200, you will be doing short circuit, which is really all you need. Each transfer type has advantages and disadvantages, but will also require different gas mixtures and current profiles or levels.

EDIT: Here is a good download -> http://www.praxair.com/praxair.nsf/0...ILE/P-8126.pdf

[CGCINC]

For your IMIG-200, you will be doing short circuit, which is really all you need. Each transfer type has advantages and disadvantages, but will also require different gas mixtures and current profiles or levels.

EDIT: Here is a good download -> http://www.praxair.com/praxair.nsf/0...ILE/P-8126.pdf

Thanks for the download.... Seems there's more to Mig than just pulling the trigger!

In that downloadf it says...

In a gas blend of at least 80 percent
argon (see Figure 5), the electrode
metal transfer changes from globular to
spray mode as welding current increases
for any given electrode diameter

I see a lot of people using a 75%/25% Argon Co2 mix but in this download for welding low Carbon steel, the lowest amount of Argon the show is 80%.
Should the mix be 80/20 instead of 75/25? I'm not sure if you can specify the mix you want at the welding store or you just get what they have?

[zoama]

Performance (Mark) say he uses C18 which is 18% C02 and the balance argon. He says in gives less BBs. I'm gonna give it a try when my current tank is empty.

[CGCINC]

I'm going tomorrow to get a bottle so I'll see what they can do. I might do a 80/20 and see how it goes..

[CGCINC]

Another question about Transfer Type was:

Is it something you change on purpose and for a reason, or is it something that just happens as you lower/raise voltage and wire speed?

[DaveO]

For a while I got (and pretty much still have) my jockeys in a twist over this topic: should I adjust weld parameters to achieve a particular transfer type or adjust weld parameters to the setup required? And I untwisted by following the online weld calculator and letting the transfer type resolve itself, figuring that for the moment I need to concentrate on fundamentals of technique and producing a sound weld. My >guess< is that the different transfer types each have their nuances and applications and that actually choosing one over another comes with experience (that I don't yet have).

[CGCINC]

For a while I got (and pretty much still have) my jockeys in a twist over this topic: should I adjust weld parameters to achieve a particular transfer type or adjust weld parameters to the setup required? And I untwisted by following the online weld calculator and letting the transfer type resolve itself, figuring that for the moment I need to concentrate on fundamentals of technique and producing a sound weld. My >guess< is that the different transfer types each have their nuances and applications and that actually choosing one over another comes with experience (that I don't yet have).

Yeah, I was pretty sure Mig welding was simple and you point and shoot. Then I read all about Transfer types and got all twisted like you.
Guess I need to relax and let the sparks fly for awhile.
Thanks!

[DaveO]

I was pretty sure Mig welding was simple and you point and shoot.

I've heard GMAW referred to as "the hot glue gun of welding" because almost anyone can pick up a MIG gun and a helmet and fuse two pieces of metal together. "Point and shoot" extends the camera analogy because it reminds you of the difference between a photographer (the guy that knows his camera inside and out, and adjusts F-stops and filters and exposures and develops his own prints) and the guy that remembers to take the lens cap off.

If you have time or inclination there's more reading at ESAB University: http://www.esabna.com/EUWeb/MIG_handbook/592mig1_1.htm
The layout is a little confusing until you figure out they show a table or chart on one page and discuss it on another. For instance page 6 of the transfer discussion talks about Globular transfer but shows a table for the Spray method on the next page.

[CGCINC]

If you have time or inclination there's more reading at ESAB University: http://www.esabna.com/EUWeb/MIG_handbook/592mig1_1.htm
The layout is a little confusing until you figure out they show a table or chart on one page and discuss it on another. For instance page 6 of the transfer discussion talks about Globular transfer but shows a table for the Spray method on the next page.

Thanks.. I like to read and learn.

[DaveO]

Then it's worth it to resurface this link:
http://www.esabna.com/us/en/educatio...al-Request.cfm

ESAB will send training material on CD ROM, free for the asking, you don't even pay shipping.

[CGCINC]

Blamo! free is always great!

Thanks again!