New need a welder

[RGM]

Building is pretty simple as I said 8 columns about 15' high, base plates at bottom, pocket for glulam beams up top and one cross brace. Yup 10,000 labour is out of line that is why I am going to do it myself. Made a truck bumper years ago but I have enough welder friends to help me. Might rent as well. Don't have a problem moving anything heavy with my tractor.

[walker]

I never implied the little 211 should be used by large contractors to build bridges. I said it would be fine for him and whatever thickness he chose to weld because it was a hobby machine used in his spare time. Stop putting words in my mouth. Stop making assumptions. You are the idiot.

So maybe my response was a bit harsh, but that was a direct quote, I wasn't putting words in your mouth.
To give you an idea where my perspective on this comes from. I just finished cutting apart and rebuilding a trailer that had come apart due to being welded with a small mig. The guy who welded it was one who believed that you could just use multiple passes in lieu of an ample sized machine. I am also in the middle of a large job repairing a lot of ironwork on a big house that was welded with an inadequate welder. It is just frustrating to have to cut apart poor welds in order to make good welds. I suppose that it is not just the poor welds but the poor cutting and fitting that add to the poor job. Perhaps then the guys that spend the money for the appropriate machines have also made the investment in learning and other tooling. At the very least there is some correlation.
I will still disagree with you when you say 'fine for him and whatever thickness he chose to weld', because a 211 just doesn't put out enough amps for ''whatever thickness'. It is not really for use much above 1/4", and certainly not for making plate girders, even with multiple passes.

[Matrix]

You're welcome to your opinion but ... I mean ... seriously .... a weld is a weld. There's no middle ground. There's either fusion or there isn't. And when you lay another pass over the first pass the same rule still applies. There's either fusion or their isn't. There's either slag inclusions or porosity or there isn't. None of that is the fault of the machine. It's the fault of the operator. I'm not a big fan of GMAW myself so I know how you feel but like it or not, wire feeders are taking over. Maybe not 211 autoset wire feeders, I'll grant you that. They just don't have the cajones to get any production out of the them on a job site but for a home welder they can tackle anything as long as you stay within their limitations for amperage and duty cycle. I've seen 2.5" thick vessel shell course longitudinal seams done with track mounted GMAW oscilators running .035 wire. The operator sets the oscilation width, pause times at the sides, step size, travel speed and other kinds of parameters along with the usual voltage and amperage setting but it's still .035 wire running short circuit transfer. Volt and amp settings still have to be in the ball park for .035 wire. No matter how you slice it, digging of the parent material is minimal in GMAW with short circuit transfer so size of machine only affects amperage and duty cycle but the weld itself is still either a weld or it's not a weld. There's either fusion or there isn't. If the wire selected creates a weld deposit with mechanical properties equal to the parent metal then what difference does it make how many passes it takes?

I've been on jobs where the steel is 1.75" thick and they made me weld it from bevel to cap with 3/32" 7018. Wasn't allowed to use thicker rod. That's a lot of passes.

If anyone can proove that the 211 can't put in a weld that has any fusion, I'll step in and adjust the settings and prove that it does and then I'll get the job done. It will take a while with a little machine like that but I'll make it happen and nobody will be coming after me to gouge it apart because it wouldn't hold together. You can weld something with a thousand amp power supply and you still might have to tear it apart if the operator did a poor job of it but that's not the machine's fault.

[walker]

I agree, to a degree, with most of what you say. I disagree that a MM211 can put out enough power to weld 3/8 steel well. 3/8 steel takes somewhere in the neighborhood of 23-25 volts and 230-250 amps to weld, the 211 can only put out 20 volts at a little over 210amps. It just does not have the horsepower to penetrate very deep into the 3/8 plate. It is also less than 10% duty cycle at its top end. To suggest that a pro could get away with it for a few small welds is one thing, to suggest that a hobbyist could do it on structural steel members is a totally different thing, and that is where I disagree with you.
To prove or disprove that it could possibly do it, and do it as well as a bigger machine would likely require a cross section cut from weld and some expensive testing that neither of us would pay for to prove a point. Destructive test may yield a reasonable result and I would be interested to see it. The biggest small machine at my disposal is a MM140, otherwise the next step up is my xmt304. If you are interested in doing a test PM me and we can chat to see what is possible.

[RGM]

Thanks for all the replies. I posted on this site to get info from guys that weld for a living. I want to use the right machine for the job. If I need to rent would a stick welder be my best option or should I get a mig. I think I can do all the welds horizontal but it will be done outside or maybe in a neighbor work shop

[go2building]

With limited welding skills, it is way easier to do a structurally sound weld with stick.
Kevin

[Helios]

With limited welding skills, it is way easier to do a structurally sound weld with stick.

As someone with limited welding skills, I agree.

On any weld that matters (anything except auto body), wire feeders scare the bejesus out of me.

[7018 Farmer]

This is as easy as a mug welder!

[admweld]

As someone with limited welding skills, I agree.

On any weld that matters (anything except auto body), wire feeders scare the bejesus out of me.

I have put numerous pintle plates,3/4" thick on many of trucks with a 250amp mig .035 70s wire.Not a problem,but with that said i got 25yrs of experience behind me also.