Porosity and Otherwise Lousy Welds

[OkieDave]

I'm building a smoker, and I welded the hinges on this afternoon. I'm not particularly happy with the quality of my welds, and I was hoping to get some feedback from the more experienced members.

Background info: the pipe is 3/8", the hinges appear to be made of 1/4" material. Yes, the pipe is rusty, but I wire-brushed the weldment site thoroughly (knotted wheel on a handheld grinder). MM252, .030 ER70S6, 24.3V/500ipm (recommended setting), 25CFH of C25.

The pictures:

 

[Shield Arc]

I'd back the gas off to about 18 to 20 CFH.
How much stick out are you running?

 

[OkieDave]

Initially, so little that I welded the wire to the contact tip! After that little mistake, I think I probably had 1/2" to 3/4", but don't hold me to that; I'm inexperienced enough that I had my attention full just trying to keep the puddle in generally the right place.

 

[Shield Arc]

For Mig welding I run about 3/8" stick out.
What brand of wire are you running?
For .030" wire I would try 22-volts. Wire speed around 400.

 

[OkieDave]

I'm using Radnor right now. It was what the LWS carried.

 

[Shield Arc]

First chance you get, buy some Lincoln L-56 wire. Lowes carries it.
This is some L-56. vertical up hill, and a flat fillet weld.

 

[sdef]

I had a similar problem with my Miller 211 using flux core .035. Fought it for awhile before I gave up and switched to a different wire and brand and my porosity issues went away. It seems the wire I was using was contaminated in some manner.

 

[Mysfyt]

Well, I'll shake up the cart a bit. On a MM 252 with .030 wire, I'd be at 18.5 volts and about 225 wire speed with ShieldArc's gas recommendation. This is using straight Co2. Even with 75/25, I wouldn't be much higher than this. Grab a piece of scrap and give it a try. I just did a job at a place with this very same welder and wire size and I think my final settings were 18.8 and 230. The people who use the machine (they're assemblers, not full time welders) just couldn't believe how smooth it welded. Miller recommendations on their machines has ALWAYS been way over what I settle on for a sweet spot. I've owned about a dozen Miller machines going back to the mid 80's because they are built only about 30 miles away from where I live.

 

[Shield Arc]

Here is a fillet weld on 3/8" thick material. Made with Lincoln's .030" L-56 Mig wire. 29-volts. 224-amps.

 

[sdef]

Here is a fillet weld on 3/8" thick material. Made with Lincoln's .030" L-56 Mig wire. 29-volts. 224-amps.

Only in my dreams...