Bugout4x4

Honestly, I have only been in a situation once or twice where I had to do this with a gap like that. And both turned into a mess for me. Is it better to try and run the first side a bit cooler and then burn a little hotter on the second side to get a little more penetration having the first weld already backing it up a bit in the gap? Or the opposite? or burn them the same?

Rogue4x4

Well, you can't always hit the second side...which is why open root is important. You need proper penetration and fusion from the get go when you can't burn the other side. More important in pipe welding, but trust me, you need to have all your bases covered in the working world. Things don't present themselves on a silver platter all the time, haha

You want proper penetration and depth of fusion at ALL times. In the working world, a lot of the parameters are there on the work order, follow them, and you should be good. Not only are the processes controlled, but the people working it as well, which is why certs and quals are so important. Certain joints and fitments are qualified in advance on a process level, then the people who work those are also qualified.

Bugout4x4

So let me get this right, When running the first side you have to penetrate all the way through the gap to also be completely penetrating and filling in the backside of the gap at the same time? Then the second side run is just penetrating into the already closed up gap to add secondary strength?

Rogue4x4

For the first question, yes. Needs to penetrate all the way through, fill the gap. Properly. On most industrial jobs, they are subject to inspection, but you can't see the inside on a visual, so the welds are inspected either with xray (rare, mobile xray isn't cost effective) or with ultrasonic testing (more feasible and a great indicator of voids)... Second one, depends, if you can't run a pass on the backside, the first pass on the OUTSIDE needs to do the job. Think of it this way...You need to run a bead on a 4" pipe to connect it. The pipe run is 20' or so between ends. How do you run a second bead on the inside?

You don't.

You need to run a sufficient bead in the first place.

Bugout4x4

Yeah I understood that part, especially pipe. But wasn't sure if in this particular "T" off situation where you can get to both sides whether that first side was just as critical because you do indeed have the ability to come and finish up a solid penetration with the second side weld. So I'm going to guess it is just common practice to go ahead and make it all solid to the back side with the first run on one side.

Just trying to learn here.

Please tell me you are allowed to bevel the "T" off piece on the first run side and didn't have to burn back through a flat butt cut to get penetration all the way through? lol

Rogue4x4

On the stuff I've been working so far, no. But material thickness comes into play here. You can bet that anything greater than 3/16" is beveled, when doing the MIG process. The next round of stuff I'm working is 3/8". The open root is 1/8", with a 35* bevel on the plates to be joined, for a total of 70* bevel angle. Now, the root joint also gets a root face of 1/8". All of this is part of fitment and prep to weld.

Like this...

Rogue4x4

Now imagine a second plate mirrored like the first, the root gap is set at let's say 1/8", which means the open root gap is 1/8" on all sides. You need to fill that gap sufficiently with weld bead. Then the rest of the bevel is filled with multiple passes...until you get a sufficient cover. There's a lot involved.

Rogue4x4

I'll try to get some good and bad pics this next week.

Rogue4x4

Got some from earlier projects...here you go

First pic is bottom side of open root. Second is topside cover pass

Rogue4x4

Notice on the top pic...fusion is good between both plates. Bottom pic is just cleaning up the weld on top...

Bugout4x4

Lol, yep it would be a huge pain to try and burn all the way back through thicker material without a bevel prep.

Bugout4x4

Looking forward to it!

Basslicks

Damn Roni.... you're gonna be taking all of us to school by the time you're cert'd! Not that I had any doubt in your skills to begin with, but you're kickin' ***!

XJwonders

Forgot to post this a week ago. But here it is

Welding 304SS for DuPont









Note the feathering (that's how you are supposed to finish off the end of the weld.



Enjoy the pictures

TeXJ

Hey question for the masses:
I have a Hobart Handler 140. I'm currently using flux core and I went through the first spool that comes with the welder and then I installed another one I got from like Home Depot or something. So now when I hit the trigger to get more wire out of the gun it works for a short time then it just stopped and the wheel inside the welder that feeds the wire is just siting there spinning and had a bunch of metal shaving around it.

Not sure what's going on. It was working for a few passes then this happens.

Any ideas on what the issue could be? I did try and tighten the tension down, but that didn't seem to help any.