Welding Tips and Tricks

I am very new and am practicing MIG welds. Using mfg settings on 11 ga and the weld looks ok but when I slice it open I see cracks. Looks like a cold weld but I am very inexperienced. Any help would be appreciated.
Pete

In order to get a better examination of that saw cut section, you need to polish the cut end to a bright shiny finish. Then use some etching fluid (like navel jelly) to develop the weld/base material finishes. That enables you to see exactly the weld bead profile and penetration results.

With MIG, T joints can be tricky because travel speed and contact greatly influence results. You really need to aim the tip directly at the seam at a 45* angle to the work, and maintain a slight angle forward or back relative to your travel direction.

Without seeing the fully developed results, the right side “appears” to have better penetration but also a lot more weld bead (tells me your travel speed was slower). Left side looks like correct profile, but wrong angle/distance resulting lack of penetration. Etch it and see what’s what.

Thanks. I will get some better grit and polish.

Still waiting on my finer abrasives. I welded some more T joints with 11ga. Lincoln 215MP .030 using Mfg. settings and I can still sometimes make out some straight lines in the cross section cut. I increased the wire feed and left the voltage the same at 19 but it still looks like I need to get the bead to "dig" into the plates deeper. Not sure where to go from here. If I go slower, the bead just seems to build up without any deeper penetration. Any suggestions?

Torch angle? Torch distance to your work? How much wire is sticking out past the contact tip?

The MOST frustrating aspect of MIG is: it looks easy but it’s very difficult to get truly good welds as a new welder. There are so many very subtle aspects to welding, and MIG is no exception. Too many new welders thin, “Oh, point the gun, pull the trigger, and I’m welding!” Well, you are, but you aren’t welding well.

Jody has published dozens of really good videos on his YT channel for MIG. Settings, motion, distances he’s holding, and then he cuts and etches to show the results. If you haven’t, watch about a dozen of those. Keep practicing, and make small adjustments in your technique versus tweaking the machine.

Gun angle 45* at the joint. Maybe a 5-10* angle pushing the puddle. Feed the wire at the leading edge of the molten pool. Watch the puddle size grow to consume the vertical and the horizontal material equally. Count out loud (it helps) 1, 1, 1, 1… Every count move forward slightly, pause, count, move, pause, count, move… See if that cadence helps you get the results you need. More pictures too!

Here is a picture with a better polish. Mfg settings and 1/2" stickout. I have looked at Jody's videos and will keep adjusting.
Thanks

From what I can see, it looks solid. Without using an etching compound it is hard to see the actual penetration of the weld bead.