Different techniques for welding??

[85mudblazin]

What is the strongest way to weld with a mig welder??
Such as methods as welding tiny u's or back tracking the weld and other such methods??
Thanks
-Chris /forums/images/graemlins/thumb.gif

 

[84_Chevy_K10]

According to all that I have read, you are not supposed to weave with a MIG welder.

Although I'm far from a skilled fabricator, I tend to agree. I have never done anything but point, shoot, and drag with a MIG with good results.

There was a long, heated discusson on Pirate4x4 about this very subject. A number of people stated that a weave will not produce as much penetration and that a stronger weld would be produced with the gun pointed at the root of the joint for the duration of the weld.

There are points to using both methods though, let the discussion begin.

 

[84gmcjimmy]

You're only supposed to weave when you are welding thicker metal-wider area heated and welded

 

[Esteban86K5]

I have used many different techniques. I use a J-stitch when wleding different gauge metals, I use a u-stistch when a larger than norm gap is present, a drag method on most thinner metals, I've even used the series of tack welds.(although never on something structural or load bearing) But the one I use the most is the basic back stitch. It works well for me and I am able to produce some nice looking and well penetrating beads.

/forums/images/graemlins/thumb.gif

 

[84gmcjimmy]

How do you do the back stitch?

 

[85mudblazin]

just weld forwards then go back into the puddle about a 1/4 of a inch or so then continue on and do that after each one.

 

[84gmcjimmy]

hmmm, I will try that/forums/images/graemlins/woot.gif

 

[tRustyK5]

I push not drag...no 'puddle manipulation'. Dragging is best with flux cored wire, seems to cause lack of fusion with microwire though.

A weave is only 'OK' as a cap on a vertical weld. Other than that multiple stringers are stronger than any weave.

Rene

 

[85mudblazin]

anyone??

 

[84gmcjimmy]

I just skimmed through my book again, and how about tiny little circles?

 

[84_Chevy_K10]

As Rene said (and he's the expert) there is no reason to manipulate the puddle with a MIG welder. A weave will often just spread the heat out and give you poor penetration and a weaker weld.

If you've got a thick piece, do it in multiple passes.

 

[BSav]

I took a frabraction class this last semester in mostly wood but we got in to some metal. We used a mid size Lincon mig (wire feed) welder and I got taught to pull back and do that while making cursave "c's". It worked for me you can tell when you inspect the weld, it looks nice like one seen on a factory weld or a motercycke and mountain bike. Thats just what I was tought.
Brian Sav

88 GMC Jimmy, 350, stock and rusty chrome wheels for speed

 

[tRustyK5]

[ QUOTE ]
I got taught to pull back and do that while making cursave "c's".

[/ QUOTE ]

That is a crutch and a cheat, but not necessarily wrong. MIG is pretty forgiving...and without a little movement it can be tough to guage your travel speed. A big weave I wouldn't do, a conservative 'whip' I will occasionally do.

Most important is to keep the wire pointed into the throat of the joint. If you move out of that zone you're not getting as much penetration as you could.

Rene

 

[BadDog]

Lots of different things, depending on what I'm dealing with. A simple stringer is often used, but it depends on metal, orientation, etc...

For instance, this is something I do when pieces meet sorta flat. I generally bevel the edges on anything of 1/4" or so and up. Then I use a sort of tear drop pattern and run it hot. Direct the arc into the bottom of the "V", let a puddle start to build, letting the arc cut into the steel on both pieces moving forward slowly while the puddle builds behind. This is usually a "drag" orientation. Then move back in a loop to sort of cap it off and take care of any undercutting.

For right angle joints welding vertical, I now often use a similar "triangle" up weld that I saw on one of the boards (PBB, or Hobart?) some time back and found it worked well. This is "push" to reduce fallout and pile-up.

And for thick-to-thin, I keep the arc and puddle mostly on the heavy side, looping up and digging into the thinner stuff with the "J" pattern.

I'm still working on getting a strong but nice looking weld in round tube to round tube...