[gblazer]

Hello i just bought a new amico dr 160 stick machine i unboxed it yesterday and ran a couple of 3/32 7018 on sum bed frames i started at 80amps and had to bump it up to 100 heres the thing i cleaned off rust an mill scale but the slag i tried to chip off was super hard to get off ive been welding for yrs mostly mig in production and went to ndscs i am a certified welder but im at a loss for the results in this 7018 slag any suggestions?

[Farmwelding]

Wow ndscs. Whap or Fargo? I spend my summers in rothsay and my uncle went to ndscs in Wahpeton.

[Erich]

Bed frames are not mild steel. I do not know the exact alloy or carbon content but they are MUUUUCH harder than run of the mill hot rolled angle iron. Perhaps this explains your experience.

[Farmwelding]

Yeah don't practice on bed frames. Only time you use bed frames in welding is when you don't have any angle iron around and you're on the farm and have to build something to get you by or your cheap on the farm. My uncle uses it often enough cause there is quite a bit laying around. For it's gonna hold a lot of weight then actual angle is used of course.

[cj737]

The metal you weld to has little to do with the slag releasing...

If the slag is really hard, its an indication of a cold weld beneath. Even if you used 100amps, your arc length could be too long, the metal thickness too much for the rod, or you were out of position with the rod. I prefer to run my 7018 rids really hot. Almost getting the sense of the base metal digging away and filling it with the rod as I go. This helps me avoid undercut and slag inclusions. But it is not the recommended approach for everyone.

As for removing the mill scale first, sure it helps, but I've welded right over it and not had a problem (not to a certified, tested spec though). If you are simply getting acquainted, you're fine with what you're doing/using. Just keep the arc really tight, scratching the base metal and see if that helps.

[Farmwelding]

Cleaning mill scale in your garage isn't 100 percent necessary unless you are tigging.