mig wire and tips - easy ?

You surmise correctly. No need for larger tips. Just match em up and fly. Make sure you get the right tip for your gun though!

Just remember that when mig welding Aluminium, that you get the tips that are meant for Aluminium, usually are marked with an 'A' after the size as they are slightly larger ID, and if used on Ferros welding will arc and stick to the wire.

Match the tip to the wire. For years, though, I have had good luck using a larger liner than the wire. It doesn't clog up nearly as fast and lasts at least twice as long. YMMV.

Steve

Thanks to all.

Don't know what YMMV is, though. "You Might Move Vertically?" "Your Money May Vary?" "You Made More Viscosity?"

Your Milage May Vary

HTH HAND

Here To Help

Have A Nice Day

Drats.

I thought HTH was, "Hope That Helps."

Live and learn!

"Todd Rich" wrote:

You are probably right...I tend to twist them a bit in my mind.

here's another mig question.....I'm 75% of the way through rebuilding the body on my '88 volvo 240dl and the last 10% I'm dreading since its on the under side. I've already done a couple patches on the underside and I was appalled by my results(and more than a little discouraged at my amateur-ish skills manifesting such shody work...that and I started under the car first) Now, it dawned on me that the globby nonesense that I was spattering all over the swedish underbody might have something to do with gravity pulling the droplet back on itself causeing to flare and vapourize in a very pretty way but leave a mad woman's scat all over the metal. I then did what I could from the inside (with great success and pretty beads) to patch the floor and such, but there are some places that will require an "up angle" of weld, and others that are plain and simply overhead. now I though most welding processes could be done overhead to some degree. am I wrong in MIG's case? I'm using .023" wire w/ Argosheild Lite at about 15-20 cfm on a Decastar135e 85 amp unit.

could it be something a simple as switching the polarity(clam/torch)?

now I know that purists will think that my little yellow Italian machine is shyte, hell I know its not that good, but its its what I got and it allows me to weld stuff to other stuff and I don't have the luxury of a massive rolling jig so that I could invert my car and weld the underside to my hearts content. so all that being said: suggestions? comments? querries?

TIA,

-mark, (ottawa, ON, CAN)

Hi Mark,

Overhead welding with MIG is routine and should not cause too many problems.

1. Try turning the heat down a little. That will allow the puddle to harden quicker.

Or:

1. Try increasing the MIG torch's travel speed. If you are getting "mad woman's scat all over the metal," it could be because your travel speed is too slow, allowing metal to build up.

As for DC+ or DC-, I am not sure. I know with SMAW (i.e. arc welding), DC+ produces greater penetration and DC- will not penetrate as much, but it may be different with MIG. I haven't spent time with a MIG unit in over 15 years, and I'm just now getting back into it.

On a MIG unit, you can turn both the amperage and wire speed down low enough that individual "dots" fuse to the surface as the wire contacts with the surface, arcs, and melts away. I believe this is called "stitch welding," but I could be mistaken.

Good Luck! ~Joe