I'm a bit confused about MIG welding techniques. First off, everyone says if you're doing it right, it should sound like "sizzling bacon." But this sound only describes one welding technique, which seems to produce less appealing welds.

For example, here is what I've been experiencing:

Method 1:
With the gun held further from the work piece, the weld is produced through rapid cycles of arcing as the wire nears the base metal and shorts. This is what creates the "sizzling bacon" sound. It also produces those big, ugly, stereotypical MIG welds that sit way too high.

Method 2:
With the gas turned up a bit and the gun held closer to the work piece, the arc is constant. The weld is created as the melting feed wire creates a big molten drop which falls onto the work piece. This does not result in a sizzling sound - it's perfectly quiet except for the sound of the transformer. This method results in beautiful looking welds - they sit 50% lower than the welds in Method 1, and they look very similar to TIG welds (i.e. "stack of dimes").

So from what I can see, Method 2 is better, but I'm confused because I've never before seen MIG weld look like what I'm producing with method 2 - all the ones I've seen are like method 1.

Also, there is a bit of a drawback to method 2... I'm still trying to perfect it, but as of now, I can't stop fusing the feed wire to the tip. I've smoked about 20 tips so far.

Anyway, what gives? Is method 2 wrong?

 

How far is far and how close is close? Go the the post labeled "weld info" near the top of this forum. I do believe Jaydmcrx kindly posted a sound bite of "sizzling bacon"

Method 2 is closer to the right way to do it is what I gather from your description of the weld.

Now for what I do.

I mig weld on a Millermatic 250 or a Lincoln STT-2 Surface Tension Transfer system(it's an entirely different sound. it kind of just hums)

Anyway..

On the Miller I weld 16g mild with 75% argon/25% co2 gas at about 19 volts, 290 ipm with .035 wire. (yes I weld faster than expletive) This is almost all done vertical down. I hold the tip about a half inch away from the basemetel most of the time. I'm just guessing at the distance since it's just kind of a feel thing.

http://www.millerwelds.com/edu...r.php

plug in what you are doing and go for it.

 

The second method you talk about is not 100% good.
You are not running enough wire if it is burning back onto the tip, and that is why you get that look like TIG.
Always keep the nozzle close to the work, it allows the gas to do it's job.
The weld should not be overly convex, but you can play with inclination and electrode angle to get the desired look.
Don't forget that the wire is what gives you the bulk of your penetration with MIG welding. If you don't have enough, it can be just as poor penetration as way too much.
Get a bunch of 1/8" plates and weld them in t-joints with a small fillet weld, then hammer them over to break them. You'll quickly find what works for looks and function. Look for the parent metal to seperate, and not the weld.

 

look in my tig welding article post there is an article on mig welding it might give you some insight
-matt

 

You can achevie the stack of dimes look without doing method number 2, honestly what you are looking for is something inbetween method number 2 where your wire speed is too slow and method 1 where your wire speed is to fast. You will keep melting tips with method number 2 no matter what. You definetly will not want to try method number 2 welding upside down either...

knowing your doing it right is not something that you can learn right away either, even though it seems rather easy.