So far, I've done just about everything wrong...

  1. Terry Member

    Messages:
    2
    USA - Kentucky
    Been watching for a bit, but this is my first post.

    I decided to buy a mig welder to do body work on my car as I've had an arc welder for some time and understand that it's not a good choice on thin sheet metal.

    I hadn't found this (or any other) forum before my purchase -- which was my first mistake.

    I bought a Mig-90, which is a flux core machine that cannot be converted to gas. It is also "live wire feed". It's made by a company named Chicago Electric, which is in China... :?

    It does have adjustable wire feed rate, but the power selection is just "high" or "low".

    I've heard a lot of bad things about machines of this type -- though in my practice runs it seems to do decent welds (for a beginner). Is this going to be usable for vehicle sheet metal? Have I just blown my (meager) welder budget for nothing? Any help, advise, or comments are most welcome!

    Terry :roll:
     
  2. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    Welcome to the forum Terry.

    The cheap low power welders can be made to work, it's just more difficult to weld with them. A friend of mine has something very similar, but comes here to use my welder for any big work. He finds it easier to weld neatly using mine.

    The disadvantage of the fluxed wire is the bright white smoke from the flux makes it difficult to see what you are doing. With the live torch it's easy to strike an arc when you position the gun before welding, hence a risk of arc eye.

    On the plus side, the two power settings are probably equivalent to the lowest two settings on a bigger welder. I'd imagine it would be fine up to 1.5mm, maybe even 2mm steel so it should be powerful enough for car work.

    The learning process will probably be harder, but I should thing it would be possible to achieve reasonable results with some practice.
     
  3. Terry Member

    Messages:
    2
    USA - Kentucky
    Thanks for the info.

    The Lo setting is approximately 60 amps, the Hi about 90 amps.
    It uses a .8mm tip (it will also take two larger sizes).

    I've been playing with it on Lo, but penetration seems to be lacking even on sheet metal (and wire speed set slow). Should I start by turning up the power, or increasing wire feed speed?
     
  4. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    I'm guessing here, but if your welder settings are equivalent to the first 2 power settings on mine, then low might be good to 1mm, but high would be needed for 1.5mm.

    If you aren't getting enough penetration then try the higher setting. You'll probably find you need to increase wire speed a little to prevent the wire from burning away. Try the power settings first and then fiddle with the wire speed.
     
  5. gearb0x Member

    Messages:
    4
    The other small benifit of flux cored welding is you can remove the gas shield on the gun (if it has one) to make it easier to see :)

    Ive played with fluxcore welding and its not as bad as everyone says, yes its harder to see with the smoke but the welds can come up just as good as a gas weld with a quick wirebrush

    A friend of mine uses a hi/lo setup welder and he uses it mostly for exhausts and sheetmetal, works fine for what he does. He also cut a hole in the side of it and installed a fan from a printer or something to blow cool air on the transformer to extend the duty cycle :)

    Phill
     
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