MIG Welding Input Needed

[DanStokes]

I finished welding up my oil pan mods today. It went OK but I know not all is as it should be. I did a pretty good job of making my scallops but the welds were very "humpy". I'll repost the pic from a couple of days ago in hopes that it shows.

I ground them down somewhat but now there's a ridge from the edge of the weld bead to the original material. It works but it's ugly.

The heat seemed about right - good penetration but no burn-thrus. It was hard to set as I had two different thicknesses and the scallop had a coating on it of unknown composition. Tried to clean it off but there might have been some left. I think the wire speed was too high but the wire seemed to stay about the right distance out of the gun as I was welding.

Any ideas?

Dan

[Dan Barlow]

Looks alot better than when I tried making a V8-S10 oil pan for a four wheel drive. Using a 4.3 and a sbc. I think yours looks great.

[Barry Donovan]

looks quite hot.
all bolt up?
all good.
my ridge ground would be more like a rope..yours looks like argon'd butter.

[Deaf Bob]

Cheaper or different brands of wire feeds will have power fluctations... Try welding car doors shut..
When I was working at the tower building factory, no weld grinding allowed.. except to reweld...
My son can lay beads like a professional, and is always on me to "weld nice".."I don't want it to look like crap" ...I'm the one who taught the little shit how to weld!!

I use a small piece of scotchbrite clothespinned to the wire inside the box just before it goes into the liner/ gun.. Be sure the wire is in the big hole of the pin.. And is not slowing down the wire..
I find 0.023 works best with 110v machines... Beauty is you can use the larger tips with smaller wire..

Your welds may be the result of restarting after cooling or repositioning... Thick metal with 1/2 inch rod is more forgiving.. Helps to preheat a little..

[Huskinhano]

I have a MIG welder too. It's been a while since I did any welding with it. I'm no means a welder either but I think too fast, too hot and I'm thinking your wire is too big. Running .032"?

I actually like gas welding exhaust pipe and items like your pan over MIG.

[fabricatordave]

did you weld for long bursts or start and stop if you start and stop like in short bursts you can run hotter with out blowing holes and will kinda look like tig and lay flatter

[MR P-BODY]

There is another style of sheet metal welding known stitch
welding... run the machine a little hotter and you give it short
hits with a 25% overlap... if you do it right it will look like a tig
weld... this is the process we use on sheet metal replacement
(replacing 1/4 panels and such)... just jump around so you dont
over heat any one area

[JeffMcKC]

Looks cold from to big of wire. Thinner wire same heat or less the weld should be flatter than it is. to much wire You could turn the heat up and less wire but move fast or its going to make a hole. On things like this if I am not making a hole once in a while its not hot enough.

[DanStokes]

Thanks guys. I was using my little Lincoln 100 amp and 0.023 wire with the standard argon mix gas. I've done a TON of body panel welding but its been a while and I'm pretty rusty. The pan is HEAVY gage and the scallops are parts store exhaust pipe. I was attempting to stitch weld but I'm thinking not doing such a great job of it.

I considered gas welding the whole deal but went for the MIG because it's SO quick. I'll keep working on it. DB - maybe I should tack weld the next one together and send it to your boy!

Dan

[JeffMcKC]

I would slow my wire then

[anotheridiot]

I just use .o35 flux core wire here so your welds look great. Going to very thin sheetmetal left over after stripping and grinding its not always the heat that has to be adjusted, its how much wire you allow outside of the gun. longer length from the tip will not be as hot and burn thru. we just stitch or spot weld, its basically hit it for a second, let the glow just start to go away and move up and hit the next spot. seems to keep it cooler too. if you get to heavier metal let the wire stick out less from the tip. Its at least a way we use to not constantly change wire from welding sheet metal to 1/4 inch angle.

The only way to really know how good that weld is would be turning that pan over and showing us the color on the inside.

[DanStokes]

I didn't take any pics of the inside - shoulda done that. I brazed the inside as a leak seal so I can't show you the MIG results now. It was fairly uniform with mostly a small bead showing penetration and some discoloration. So the inside looked better than the outside.

Dan

[TC]

I would slow my wire then

Yap usually when it's getting lumpy the wire speed is to high......

[SuperBuickGuy]

the weld looks perfect, Dan. Welding thin-guage, outside corners will look like that because you're adding wire to a weld that, with gas or TIG, wouldn't need filler. You can slow down the wire, but then you'll get holes; you can increase the heat with the same result. You could do two things: 1) you could leave a gap before you weld (up to 1/8" and then do the tack/fill method), or 2) next time weld it from the inside with more heat and a bit more wire - it will weld through. One of the tricks we used to use on large, flat seams was to weld from the back with a chill bar on the front - when you do it enough, the back-side weld will have scallops just like the front - but it will be flat.

Really Dan, It looks good, bask in its glow

[CDMBill]

You are already at the right wire, gas etc. so it's going to be down to technique and that balance of wire speed and heat. Your brazing on the inside obviously solved for any potential leaks so you are really down to the cosmetics. I probably would have run a bead from the back side as I have no brazing skills and then ground the whole thing for appearance sake knowing there would be plenty of material.

Part store muffler tubing is usually alumized and I remove that with a flap wheel before welding as it will ply havoc with the weld.

This is such a cool project. I know you have the build thread in the project section, but is this a Bville effort only or will you run El Mirage too?