Mill scale and mig

Tue, 31 Aug 2021 10:08:13 GMT

go to see Welding Machine for Mill scale and mig

Having watched probably every mig welding video on YouTube, a lot of the "garage" welders seem to not remove mill scale, and mig right over it.  I have always cleaned mine to bare metal at the weld locations, even though I'm just a semi-novice/DIY doing farm-type and small project/repair welding.I fabricated a couple brackets for a sanding machine to replace the broken trunions, and I decided to clean the bevel joint, but tack welded through mill scale to see what kind of mess it made.The tacks penetrated the 3/16 hot rolled steel without any contamination that I could see.  The cleaned areas of the t-joint, of course, welded easily.What's the experience out there with mig welding through millscale on non-critical welds?thanks
Reply:I always clean, even when stick welding.Miller Multimatic 255
Reply:Originally Posted by powrguyHaving watched probably every mig welding video on YouTube, a lot of the "garage" welders seem to not remove mill scale, and mig right over it.  I have always cleaned mine to bare metal at the weld locations, even though I'm just a semi-novice/DIY doing farm-type and small project/repair welding.I fabricated a couple brackets for a sanding machine to replace the broken trunions, and I decided to clean the bevel joint, but tack welded through mill scale to see what kind of mess it made.The tacks penetrated the 3/16 hot rolled steel without any contamination that I could see.  The cleaned areas of the t-joint, of course, welded easily.What's the experience out there with mig welding through millscale on non-critical welds?thanks
Reply:There are all degrees of mill scale. A lot of the smaller thinner shapes have a very light and smooth mill scale. Not much to worry about there unless you want to run a little on the low end and still get good wet out at the edges. Larger and thicker shapes can get some pretty thick and coarse mill scale. Yes you can burn through it but it takes more heat, can leave you with some undercut or the appearance of under cut as some mill scale burns up rather than blend with the wet out at the edge of the bead. Vert up is an example of where you really need good wet out out at the edges. I generally always grind away the coarser mill scale, and give good hard consideration at flapping off the light stuff. On 12 gauge and down sometimes there isn't much edge there to risk flapping a lot off cleaning mill scale. It would be pretty rare that a weld was made worse by cleaning the metal 1st. If there is any question, do it."The things that will destroy America are prosperity at any price, peace at any price, safety first instead of duty first, the love of soft living and the get rich quick theory of life." -Theodore Roosevelt
Reply:i just got in from welding up a bracket using the mig (for a change). i always clean as much as i can. if your setting or technique is marginal then mill scale can cause big problems. i've had it where the weld just sat up against the mill scale. looked really nice but broke of easily and cleanly.i always find its much easier to weld clean metal.however most guys will just up the heat a bit and weld through it.
Reply:I just give it a quick slap with something coars
Reply:clean ..at least run a flap disc...Youll help.yourself by having nice smooth non sputtering arcs ... to me its just not enjoyable lolSent from my LGLS992 using Tapatalk