Thread: Interesting site

Here is Myth #1 of 7 in your "7 myths about mig welding"

Big Fat Mig Welding Myth #1

Mig welding warps the metal more than TIG

there are some experts out there who claim that TIG welding is the way to go on thin sheet metal body panels because it warps the metal less and that mig welds tend to be brittle when hammered flat. What? Brittle? If they are brittle it is simply because they are pounded flat before being ground or sanded flat. You can only hammer a weld bead so much before it work hardens and becomes brittle and cracks. Another thing is that a lot of Mig welds on mild steel sheet metal are done with ER70S6 wire that contains more silicon and that can make it a little harder than TIG welds because TIG welding wire is typically E70S2. So just buy E70S3 wire for your mig welder. You don’t need the E70S6 anyway.

Distortion??

Many times sheet metal will distort less, not more when welded with mig because of its low heat input and fast travel speed compared to TIG. Of course this all boils down to who is behind the helmet at the end of the day.

Watch your Inbox for Myth #2

peace out...jody collier

weldingtipsandtricks.com

Big Fat Mig Welding Myth #2



"mig welding is easy"

ok this is a hard one to explain. Most folks would agree that mig welding is easier than stick welding. Why is that? One reason really… because with mig welding, you don’t have to continually feed the electrode as it gets shorter like you do with stick. That’s it? Seems like a pretty weak argument to me. Lets take a closer look. With mig welding, you have to set the proper gas flow, set the voltage, and select the proper wire feed speed. And for some flux core wires, you will have to swap the polarity by swapping the lead connections



With stick welding….. Especially with a A/C buzz box….you only set the amperage. That’s it!

Wait a minute! And mig is supposed to be easier? Well..... That’s what they tell you! Haven't you ever heard someone say that any monkey can mig weld?

Well it is easier in some ways: it's easier to weld sheet metal. And once everything is set properly its pretty easy to run a good bead on thicker metal too. But in my experience hardly anybody sets everything properly …..and no one wants to take the time to practice on scrap metal long enough to arrive at the correct settings. So most people are welding with a handicap. And that makes mig welding a lot harder than it should be.

Watch your inbox for the next myth,
peace out...jody collier.. weldingtipsandtricks.com

Big Fat Mig Welding Myth #3



Downhill mig penetrates as long as you crank up the heat.



Don’t get me started. Don’t even get me started… I have had the opportunity to run several experiments with this one. After many many test welds of uphill vs. downhill I have come up with a rule of thumb. Are you ready for this? Anything thicker than 1/4” should be welded uphill. I am taking mostly about mild steel here and using short circuit transfer, but the same thing applies on other metals and even spray transfer. Here's the deal: the hotter the puddle the faster the travel speed. The faster the travel speed the less preheat ahead of the puddle. The hotter puddle is more fluid also and the fluid puddle tends to run ahead of the arc and actually insulates the base metal from the arc. Uphill welding on the other hand is slightly slower but gravity keeps the puddle behind the arc and lets the arc dig through mill scale and into crevices that would otherwise get cold lapped.

Watch your inbox for the next myth,
peace out...jody collier..

More Mig Welding Tips

Big Fat Mig Welding Myth #4





Stick welds are stronger than mig welds

I love this one. I worked in a fab shop once where both mig and stick welding were used. Occasionally, temporary lifting lugs were welded to heavy objects so the overhead crane could hook to them and transport the heavy object easily. Some of the old timers insisted that the lifting lug was welded with stick, not mig. Even though a lot of x-ray quality welds were routinely welded in the shop using short circuit mig, I couldn’t help but notice that some of the mig welders in the shop welded with a downhill weave and really cold. I wonder if some of there stuff fell apart in the past and the old timers were remembering that.

I suppose I can understand the fear of cold mig welds. But if you set things up properly, keep your stickout short, don’t weld downhill and weld hot enough (20-23 volts) you should have no trouble getting a sound weld. Even for a lifting lug. If you have any doubts just run some tests and get out the BFH. (Big freaking hammer) and beat the dog crap out of your weld joints and check for penetration.

Watch your inbox for the next myth,
peace out...jody collier

Big Fat Mig Welding Myth #5



110v mig welders are toy welders and are not good for anything.



110v mig welders are not toys unless you get a really cheap and poorly made welder.

If you buy a good one like a Lincoln, Miller, or Hobart, they are pretty handy. Sometimes even cheaper ones from Northern Tool or Harbor Freight work ok...but not always.

They typically use .023--.025” wire and that works great for thin sheet metal body panels. But what about thicker stuff? That’s what flux core is for. Swap over to Hobart fabshield 21b and you will be surprised at the results on thicker metals.

Tips to get the most from your 110v mig are: decrease wire stick out, clean the metal with a grinder, use flux core on thicker metal, use a 20 amp breaker, preheat with a propane torch and weld uphill.
And by the way... if you need to weld a trailer hitch, dont try to use a 115v mig.

Watch your inbox for the next myth,
peace out...jody collier..

Flux core wires are not as strong as bare wire



Hobart fabshield 21b is pretty freaking awesome. I ran test welds and bend tests on this stuff and found it to be robust. For welding outdoors it faired much better than other wires we tested. There are some concerns about toughness values and some of the self shielded wires are not rated by the AWS. But for most applications they are just as good as or better than that 7018 stick rod that has mold all over it from being in the bottom of your toolbox for 10 years.

peace out...jody collier see a short flux core setup video