welding thicker steel to thinner steel?

[shott8283]

i ran into this problem a while ago and with out the knowledge i couldnt figure out how to get a really good beed.

i was welding 20 or 22 ga sheet steel to 1/8" thick angle steel.. obviously i cant run the power i would normally for 1/8 to 1/8.. so what would be the correct method of joining these two different peices of steel?

this was a frame for some electric fans i put on my truck.

[standles]

I am by far an expert. Much more of a hack. However, when I run up on that problem I set the heat a little higher than for the thin and angle the puddle to favor the thicker pc.

I have run decent beads like that.


I am sure more expert opinion will be along shortly.

Steven

[tacmig]

Burning holes suck!

Most pro welders have developed their own method for this problem and for pro's it should only be work at this point and not a problem. In any event the idea of cranking it up just past the thinner materials weld level and focusing on the heavier material is good advice. All situations are going to be different based on the material. I usally for the most part weave with emphasis on the heavier material at the level for the heavier material. I'm sure you'll get some other great info from others on this. Oh by the way, this is why a lot of people prefer tig'n for output control. Basically with tig, this is not even a problem!

[Jolly Roger]

Actually this is what a mig was made for, but using sticks I leave the amps set for the thicker stuff and concentrate the heat in the heavy side and let the puddle flow into the thinner (flow into, not on to). I could show it to you and it would be oh wow, but I can't figure out how to explain it. I actually learned the technique from my dad as a kid using an o/a welding torch and later he showed me how to do it with sticks. I use the same technique with a mig as well (mig was almost nonexistent back when dad was teaching me this stuff).

Ok, I will try and give an example of what you want to see in the puddle. This will only work if you know how to weld with o/a. When welding with o/a can you see the way a drop of filler metal that got dropped a little too soon flows into the puddle when the heat and puddle get to it? If so this is what you are looking for, the fluid flowing of the metal. I don't know any other way to try and explain it.

[Jolly Roger]

Oh, don't even try it with 7018, use 6010 or 6011, size 3/32. I would recommend 6011 as it doesn't have quite the dig and is a little more forgiving than 6010.

[welder_one]

do that just the way jolly roger said and you can weld the world, and pass tests as well. only problem is, i caint explian it either. but with mig, you can set heat for the thicker of the 2 pieces and dont favor the thicker metal, keep the bead centered between the 2 pieces, just spend less time on the thinner stuff in your weave. make sure to pay attention to your puddle.

[Jolly Roger]

On thin stuff like that I usually run downhill with the mig and don't weave at all.

[kiwi]

Hey Guys,
It is odd that this post came up! I got off work tonight and I started to work on my trailer attaching 16 GA fenders to 3/16 angle. I was not sure how to do it properly so I made some test coupons and experimented a bit. I set the tap hot as far as the 16 GA was concerned and ran the bead a little fast so as not to burn through the fender. When I wove the bead I tried to concentrate the heat on the 3/16 angle iron. The result was a strong bond that held up to the hammer test and produced a reasonable looking bead. Is this an acceptable way to do this? I will post some photos this weekend.
Thanks,
Nick