Tools & Fabrication - MIG welding wire thickness for 16 gauge exhaust pipe, contact tip question

I've been doing some welding on 16 gauge exhaust pipe for turbo plumbing kit fabrication. I have a Hobart Handler 140 welder, .035 wire, and C25 shielding gas. I mentioned to someone else I had to be really careful to watch what I was doing, because I was having issues burning through the metal when I was getting the welder dialed in. They mentioned I should try smaller wire (.030, or even a little smaller) because it won't require so much heat. The quick reference chart in my welder lists settings for .035, .030, and I believe .024.

I was just wondering what everyone thought about going to a smaller diameter wire for the exhaust pipe I've been using. My welder came with a spool of .030.

Also, I picked up some longer, tapered welding tips at the metal shop that I've been using since I began learning how to weld. I tried switching to the more stubby flat-nosed tips, and had a real hard time adjusting. The longer tapered tips allowed me to really watch my angle and make sure I was staying on the seam of the metal, but the blunt nosed tips were a good bit shorter, and made it harder to see my work past the end of the gun.

I've only been able to find the longer tips in one place, so it seems they aren't as common and I can only assume most people use the shorter tips. Just wondering what your thoughts were on that too.

I've had good luck with the .024 wire for exhaust pipe. The .035 and even .030 gave me problems with burning through.

you have to crank up the wire speed with the .023.

You can do it with .035 but it is much easier with the smaller wire. Would go .025

How about the contact tips....do you all use the shorter ones that are much more common?

I use the shorter tips. The longer ones keep your weld puddle a little bit farther away from the shielding gas. You should see better results with the shorter ones assuming you're able to maintain control of your gun.

I haven't had a problem with lack of shielding gas that I can tell...I've been welding inside my garage with the door open, but not an excessive amount of wind. I could see it being an issue outdoors or something.

The problem with the shorter tips is that a lot of my welds are on the inside of a 180* bend or so, and the gun makes it hard to see the seam.

I'm going to try a .025 ish wire and see how it works. I'm hoping it'll be a bit easier without having to worry so much about a burn through.

I use .023" and it works well on steel up to 1/4" thick. Use the long tip with the shield about 1/16" past the tip. Practice control and burn-throughs wont be as much trouble unless you're bridging a gap without a filler

I can't find a "long tip" anywhere except in .035...maybe my google-fu is weak.

Burn thru "dingle berries" are deadly in a turbo application. Use care to clean all the welds on the inside...Ask me how I know this!!

Ask me how I know this!!

Please post pics of said carnage.

don't need to keep garage door open when MIG welding.