Clean MIG weld parts

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Is there any general guidelines out there to make cleaner parts after MIG welding?  I know there will be smoke on the parts.  Does increasing or decreasing gas flow help?  Different types of sheilding gases make cleaner parts?  Obviously the cleaner the parts are before welding will help with the end result.  Any help would be appreciated.
Reply:The gasses, wire speed, and wire type will all help with the slag but there are always trade offs. for example an 80/20 mix will give you a cleaner weld than a 75/25 mix. But you wont have as much penetration in your weld.There are no problems. There are only solutions. It's your duty to determine the right one.Hobart Handler 210Airco 225 Amp MSM Stinger
Reply:If you want a clean weld go tig.There are no problems. There are only solutions. It's your duty to determine the right one.Hobart Handler 210Airco 225 Amp MSM Stinger
Reply:IMO, after worrying about cleanliness and fit-up of parts, spending the time to "tune" the machine is an absolute must to get very clean welds. If you're welding on heavily scaled plate and are running on the edge between Short circuit and globular transfer then you will get dirty welds, without a doubt.I run C25 gas with wire diameters from .023-.035". Stick-out length and gun angle can also greatly affect the quality.I don't use any anti-spatter sprays on my parts..sometimes I give a shot to the gun to make cleanup a little easier. Here are some examples of my MIG welds. No post weld clean-up.http://all-a-cart.comWelding Cart Kits and accessories
Reply:Are you wanting the weld as clean as TIG? What you are seeing on the photos above is a "clean" MIG weld. The impurities in the metal are floating to the top of the puddle and solidifying. I'd try power brushing the weld while it's still hot as an alternative finish.Lincoln SA200's... at least 15 - 20. They come and go. Growing partial to the "Short Hoods" in my old age. Last count on Short Hoods was 13 in possession.
Reply:Originally Posted by hobohiltonAre you wanting the weld as clean as TIG? What you are seeing on the photos above is a "clean" MIG weld. The impurities in the metal are floating to the top of the puddle and solidifying. I'd try power brushing the weld while it's still hot as an alternative finish.
Reply:LOL........   Great welds ZTFab. You set a standard I doubt I'll ever be able to reach.......Miller Bobcat 250Syncrowave  200Millermatic 252Spoolmatic 30ASpectrum 625 X-TremeMaxstar 150SVictor O/A torchesDewalt angle grindersWelded on/off for over 40 years.
Reply:ZT,Every time I see your welds I say "HTF does he do that?"Outstanding.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:ZT Fab you have a good hand fair play that is some of the best mig I have ever seen.
Reply:First thing to do is to grind your joints down to shiny metal before fitting-up. that can reduce smoke noticeably. Cleaner weld are always better welds.Increasing gas flow won't help. It may introduce porosity into the weld by creating turbulence in the gas stream. Gas flow should be not less than 25 cf/hr and not more than 40 cf/hr (11-18 l/min.)You can reduce smoke by using a shield gas with a greater percentage of argon and a lower percentage of other gases. For example, 85Ar/15%CO2 versus  75/25%CO2.Excess smoke is often an indication of poor voltage and WFS parameters. . It's often an indication of uncontrolled "globular transfer" which is caused by parameters being outside the optimal range. With globular transfer a large molten drop forms on the end of the wire. The drop is supported underneath and prevented from fusing with the puddle by the arc which is too short and too dense. The surface of the drop becomes superheated by the arc and vaporizes, producing smoke. Smooth consistent metal transfer action = a lot less smoke. If you end up with a large blob on the end of your wire when you let go of the trigger, that's solid proof of globular. I'm talking if the droplet is 2x the wire size or more. If you have a nice little round droplet just slighly bigger than the wire, that's what you want to see.Hope this helps Last edited by Joshfromsaltlake; 08-03-2012 at 06:31 AM.
Reply:Originally Posted by Trailer monkeyZT Fab you have a good hand fair play that is some of the best mig I have ever seen.
Reply:Thanks guys. Just trying to show that MIG can be a fairly clean process with some tuning of the parameters.http://all-a-cart.comWelding Cart Kits and accessories
Reply:Originally Posted by ZTFabThanks guys. Just trying to show that MIG can be a fairly clean process with some tuning of the parameters.
Reply:Originally Posted by Joshfromsaltlake With globular transfer a large molten drop forms on the end of the wire.
Reply:I found I got the "blob" when not grounded well enough.
Reply:Nothing personal Josh, but I think I'll stick with ZT's methods.Frankly, I really don't see anything in your photos that I'd be bragging about.And I don't think it's the camera that would not make me want to be "schooled" by you.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:Originally Posted by SundownIIINothing personal Josh, but I think I'll stick with ZT's methods.Frankly, I really don't see anything in your photos that I'd be bragging about.And I don't think it's the camera that would not make me want to be "schooled" by you.