MIG Stainless to Mild Steel?

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SteveHGraham
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Re: MIG Stainless to Mild Steel?

Post by SteveHGraham » Sun Aug 18, 2019 9:17 pm

I don't recall whether I was man enough to post a photo of my stick welding effort. I was trying to fix a bush hog that had some broken welds. I looked for information, and somehow I was led to believe that AC was the way to go. I used E7018.
08 20 17 bush hog weld up close small.jpg
I ground it out and managed to use my MIG with a generator. By my standards, the results were very nice. But I sunburned my legs.
10 01 17 bush hog welded with MIG and generator small.jpg
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choprboy
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Re: MIG Stainless to Mild Steel?

Post by choprboy » Tue Aug 20, 2019 3:56 pm

SteveHGraham wrote: ... I used .025" L308, because I had it. I am not a great welding guru. I assume the settings for .030" are too hot for .025", right? Anyway, I used a .030" setting from the chart on the welder, and I made the mistake of picking the larger of the two likely looking metal thicknesses. I guess I should have started two steps down and turned the welder up if necessary. I did lay a bead on a sheet of thin steel first, and it looked fine.
What did it sound like? I have done lots of 16ga sheet and square tubing now, some to 1/4" plate and tube, using .030. Once I switched to .025" it became so much easier. You can leave the heat setting where it is, just remember to crank up the wire feed speed. Start with the same setting as the .030 wire, increase the speed by about 20-25%, and then keep increasing the speed until the arc changes from a stutter to a continuous crackle. If it seems like the wire speed is too high and the wire is jabbing into the weld and trying to turn the speed dow a little bit doesn;t really help... turn the speed up a bunch.
SteveHGraham wrote: ... I was trying to fix a bush hog that had some broken welds. I looked for information, and somehow I was led to believe that AC was the way to go. I used E7018.
Depends on the 7018. Most is DC+. Lincoln makes a 7018AC (often found in HD) that will run DC+ or AC. Your stick weld looks like a combination of wrong polarity (or running AC with a DC stick) and moving too fast. Stick welding puts down lots of material, but tends not to move too fast (until the rod and base metal get hot).

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SteveHGraham
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Re: MIG Stainless to Mild Steel?

Post by SteveHGraham » Tue Aug 20, 2019 6:20 pm

The rods were probably "Lincoln Electric 1/8 in. Dia. x 14 in. Long Fleetweld 7018AC-RSP E7018 Stick Welding Electrodes (5 lb. Box)," because I got them at Home Depot, and that's what their website lists.

Yesterday I found a local metal supplier and bought 8 feet of 1/8" x 2" hot-rolled for practice. I also got me a Vulcan welding cart from Harbor Freight. Much nicer than the one that came with my Lincoln MIG.
Every hard-fried egg began life sunny-side up.

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warmstrong1955
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Re: MIG Stainless to Mild Steel?

Post by warmstrong1955 » Sat Aug 24, 2019 1:38 pm

A few notes on your weld with 7018.
I had nothing but a Lincoln buzz box for few years, and 7018 will weld fine on AC. 7018AC is even better.
I see paint, rust, and who knows what. Clean up where you are going to weld. Grinder & a wire brush. 7018 is not tolerant of dirt & rust like 6011.
7018 likes a short arc. You also don't oscillate forward & back like 6011. Slow & steady with 7018.
Angle of the rod should be about 10 degrees off vertical to work.
Your speed looks erratic, and too fast. Use two hands. Steady yourself by leaning one hand or arm on something. I keep all kinds of short blocks around for that.
Learn to read the puddle. Trick is to know the difference between the puddle of molten metal, and the molten flux. Not being able to differentiate the two, can cause you to travel too fast. Too fast, move too far away from the puddle, and the arc will not be smooth and consistent.
What amps were you running? You may have been on the low side too.
Today's solutions are tomorrow's problems.

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SteveHGraham
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Re: MIG Stainless to Mild Steel?

Post by SteveHGraham » Sun Aug 25, 2019 4:38 pm

That weld is two years old. I have no idea what I was doing. I'm sure I used a knot wheel on the metal before I welded, but the crud from the flux covered up the clean bits. The MIG welds that went over it looked very nice.
Every hard-fried egg began life sunny-side up.

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warmstrong1955
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Re: MIG Stainless to Mild Steel?

Post by warmstrong1955 » Sun Aug 25, 2019 5:15 pm

SteveHGraham wrote:
Sun Aug 25, 2019 4:38 pm
That weld is two years old. I have no idea what I was doing. I'm sure I used a knot wheel on the metal before I welded, but the crud from the flux covered up the clean bits. The MIG welds that went over it looked very nice.
Well....I can see that! ;)
If you cleaned things prior to welding....I don’t see that.

With MIG & solid wire....it’s pretty easy to see the puddle. No flux involved.
With dual shield wire, it gets more interesting, because part of the puddle is flux.
With stick welding, all the shielding is done with flux....it’s a bigger deal, and the flavor of rod makes a big difference as well....and until you figure out the difference between molten metal, and molten flux....ya’ll got a problem.
Self shielded wires, are more similar to stick....but none I have used, are as good. In a word....yuck. I still pass on that stuff.
Today's solutions are tomorrow's problems.

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