[NU_BLUE]

I have a question. Most of you on here are good welders. I was wondering where ya'll learned it? Do you just pick up over the yrs. or were you trained, etc?

I've played around with a stick welder more times than I remember and I've got the basic idea from welding on farm equipment, etc. However, I would like to get into MIG and TIG welding....I'm just curious where to start.

[Norm Peterson]

Couple of things that I don't think anybody has mentioned yet . . .

I really don't know how to put it into words, but the sound that the welding process makes is some indication of how well things are going. I think it was one of the weldors in the maintenance dep't where my Dad worked that told me that one.

Acetylene welding with steel wire. If you don't learn a thing or two about welding and the weld puddle from trying this, you probably won't no matter what process you try.


Mostly, my own learning has come in little bits like that. Dad tackwelded plates together in a shipyard during WWII, and an uncle grew up on a farm and had a little buzz-box, so I at least had a little guidance in the beginning. I wouldn't rate myself as a "good welder", although with only a few exceptions (involving metal of dubious weldability), the things I've welded together have stayed that way, including some frame structure weld repair on one of my cars. It's not always pretty, and likely not good enough to get certified with. Adequate, I guess.


Norm

[prockbp]

I really don't know how to put it into words, but the sound that the welding process makes is some indication of how well things are going. I think it was one of the weldors in the maintenance dep't where my Dad worked that told me that one.

Well, a lot of welders say that and there is some truth to it. But Adjusting by sound does not make a quality weld. The way your MIG welding process sounds is governed by the mode of transfer. Mode of transfer is governed by 'Welding Procedure Specifications'. A WPS is a process that is proven through destructive and non-destructive testing to be an effective weld process.

So, you can not hear if your weld is good quality, but you can tell what mode of transfer you are using.

In MIG welding there are 4 distinctly different modes of transfer:
I. Short-Circuit Arc Transfer - Sound = Sizzle - The sound comes from continuous short circuiting. You are hearing the sound of electric arcs initiating many times per second consistently. This mode of transfer is not allowed in structural applications. It is best suited for sheet metal 1/8" thick or less.

II. Spray Arc Transfer - Sound = Hiss - The sound is a continuous hiss because the arc never extinguishes. This mode is recognized and acceptable for structural welding applications. You can use this mode for thin sheet metal also, but there will be excessive heat input resulting in warpage, burn through and grayed-out welds.

III. Globular Transfer - Sound = Random Crackling and Popping - This mode has an inconsistent sound because molten balls of filler metal are forming at the end of the electrode in random sizes and dropping to the weld puddle. The arc extinguishes and reinitiates at random times. This mode of transfer is unacceptable in most welding codes and must be proven out if it is going to be used. Globular transfer can be very effective, but you need to be very good in order to overcome the inconsitency that is inherent in this process.

IV. Pulsed-Spray Transfer- Sound = Obnoxious Buzz - The sound comes from an electronic on/off switch that is precisely controlled and adjustable. The arc is intentionally turned on/off in order to minimize excess heat input as well as provide a high level of arc control. Pulsed spray is the most versatile way to MIG weld. You can use it in every application very effectively. Unfortunately, you need to have extensive welding knowledge to take advantage of the full potential of this process. Once you have been taugt how to take advantage of proper pulse equipment, you'll never want to go back to constant voltage.

There is a LOT to learn about MIG welding. It seems simple and most people can make it happen, but when it's time to get serious you need to know your sh!t.


In Stick welding there is only one bad thing you can hear. You can hear when someone is "long-arcing". Holding the electrode to far away from the puddle causes porosity, inconsistency, arc wandering and is unacceptable in many applications. In DC stick welding, you should only hear the crackle of flux burning. In AC stick welding, you will only hear the buzz of alternating current.

In TIG welding you should not hear anything other than a light arc hiss in DC welding or buzzing in AC welding. Any other sound comes from dipping the tungsten into the puddle or stabbing the tungsten with filler rod.

Flux-Core welding only has one acceptable mode of transfer- Spray-Arc Transfer. The sound is a constant hiss just like spray arc in MIG with the addition of random crackling from the flux.

This post has been edited by prockbp: Oct 3 2009, 06:13 AM

[robz71lm7]

There is a LOT to learn about MIG welding. It seems simple and most people can make it happen, but when it's time to get serious you need to know your sh!t.

Best quote in the entire thread.



offtopic

One of our power plants, building a new supercritical unit, has been using a modified short circuit process for large, heavy wall P91 main steam and reheat lines:

http://www.millerwelds.com/resources/artic...IG-lead-the-way

It's pretty slick, but time will tell. It makes the old timers nervous though.