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  • MIG contact tip to Gas Cup length

    Does anyone know the proper tip to cup distance for MIG short circuit and spray arc. I know miller has a photo in their GMAW book, I have bought the book 2 times, but can't find it, I think short circuit is flush and spray is recessed about 1/4 to 3/8 inch. I would like to download that pic/description if possible to show some 'uninformed/hardhead I've been doing this for 30 year's but can't seem to make a weld without 50% splatter and no penetration types' They are using 3/4" recessed for short circuit with about 120 amps??????Thanks, Paul
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  • #2
    Re: MIG contact tip to Gas Cup length

    Originally posted by paulrbrown
    Does anyone know the proper tip to cup distance for MIG short circuit and spray arc. I know miller has a photo in their GMAW book, I have bought the book 2 times, but can't find it, I think short circuit is flush and spray is recessed about 1/4 to 3/8 inch. I would like to download that pic/description if possible to show some 'uninformed/hardhead I've been doing this for 30 year's but can't seem to make a weld without 50% splatter and no penetration types' They are using 3/4" recessed for short circuit with about 120 amps??????Thanks, Paul
    Short arc is recommended nozzle either flush or with a tip extension for close quarters. Spray with a recess. All depends on the gun/tip/nozzle you are using. My Tregaskiss with a std. tip allows plenty room for recess. 1/8-1/4" should work.

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    • #3
      Cope, thanks, I use Miller M15,M25,M40,[made by Tregaskis] and Tregaskis 260, all of which I love, do have a Tweco 400 amp, which works for Aluminum, can't seem to get the others to feed Aluminum even with Nylon liner. I was just trying to get hold of that Illustration to show these knuckleheads at work how to improve welds and splatter, everytime I need to weld, I have to practically rebuild a new gun, they undo every mod I make as soon as I am done, so it is a vicious circle, they even fool with the Stick leads to make them harder to use, 2/0 cable and 600 amp holder for welding at 125 amps????Go Figure
      More Spark Today Pleasesigpic

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      • #4
        Originally posted by paulrbrown
        Cope, thanks, I use Miller M15,M25,M40,[made by Tregaskis] and Tregaskis 260, all of which I love, do have a Tweco 400 amp, which works for Aluminum, can't seem to get the others to feed Aluminum even with Nylon liner. I was just trying to get hold of that Illustration to show these knuckleheads at work how to improve welds and splatter, everytime I need to weld, I have to practically rebuild a new gun, they undo every mod I make as soon as I am done, so it is a vicious circle, they even fool with the Stick leads to make them harder to use, 2/0 cable and 600 amp holder for welding at 125 amps????Go Figure
        Years ago I bought a used Miller 250 mp welder without leads. A friend of a friend worked for a wire wholesaler and I got 100' of 2/0 for what I would normally pay for #2 so I bought it. When I first started welding a friend gave me a like new 500 amp Tweco holder. I know why it was like new; it was too heavy!

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        • #5
          I hear you cope, I went from a normal MIG gun at school to a water cooled push pull at work. WOW my wrist has never hurt so much before. Who ever thought things up must not use them for eight hours!

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          • #6
            paulbrown,

            I like to keep it simple as to eliminate variables in my processes. I use a flush tip to nozzle juxtaposition for short arc and spray arc. This is the recommended set up for short arc and works great for spray. Just make sure you are using a good hot gas such as 92ar/8co2 or 98ar/2o2, etc. and your machine is pushing 26 volts + for .035" wire and you should have no problems.

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            • #7
              paulbrown,

              The key to spray with a flush nozzle/tip is to compensate by increasing your overall stick out from nozzle to work piece into the 3/4"-1" range. I have sprayed more than a 1000lbs of .035 bare wire like this with an XMT 304 and an air cooled 400 amp Tweco gun. It does work. I have since switched to a Bernard set up. I like it better than the Tweco. The Miller Roughneck series is also a good mig torch.

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              • #8
                HAWK,
                I'm confused. Is 92Ar/8CO2 a hotter mix than 75Ar/25CO2? I thought I read somewhere that CO2 is hotter than Ar.

                Alex
                Be cool,
                Alex

                FREEDOM ISN'T FREE
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                • #9
                  Alex,

                  The higher the argon content the hotter the gas will be generally speaking. This can change depending on the remainder of the contents. 92%argon/8%CO2 is much hotter than 75%argon/25%CO2. The 98%argon/2%O2 is still a hotter gas.

                  The hotter gas mix of 98%ar/2%O2 is excellent for spray arc of mild steel and stainless. This mix will also short arc stainless, but will yield a ropy bead. It does not short arc mild steel very well. Due to its high argon content undercut may be evident on short arc welding of mild steel. The only way to flatten this bead on short arc stainless is by increasing the wetting action of the bead by increasing the machines inductance. This is possible on machines like Miller's XMT series, Invision series, and ALT 304.

                  I prefer the 92%argon/8%CO2 for all around GMAW with short arc and spray for mild steel. It will not do stainless steel. A bit of a voltage increase will more than compensate for the penetration you will lose by getting away from the 75%argon/25%CO2.

                  The 92%argon/8%CO2 is hard to beat. It is hot enough to spray and cool enough to provide a good short arc. If set correctly you can alternate between short arc and spray simply by increasing your stick out to go into the spray mode.

                  You may be thinking in terms of penetration. The 75%argon/25%CO2 will give more penetration than the higher argon% gas at the expense of increased spatter. 100% CO2 will give somewhat more penetration than an argon/CO2 mix at the expense of considerable spatter.

                  I run a 100%CO2 or a 75%argon/25%co2 shield when running a dual shield wire such as E71T-1 which contains an inner flux shield, but also requires a shielding gas.

                  The higher the argon content the more expensive the gas mix. a 100% argon is not an effective mig gas as there is substantial undercutting. However, it is an excellent all around gas for tigging of mild steel, stainless steel, and aluminum.

                  Here is a side note just for general information. Most of the Miller GMAW process machines are tested and rated with a 75%argon/25%CO2 as it is a good general purpose readily available shielding gas.

                  I hope this helps and is not too much information. My wife has more than once accused me of giving too much information.

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                  • #10
                    HAWK,
                    You are a veritable cornucopia of information. I've learned more since joining this forum than I have in the last 10 years. Your answers are always in the X ring. I appreciate everyone here at AskAndy. You are a great bunch of people.

                    Thanks again,
                    Alex
                    Be cool,
                    Alex

                    FREEDOM ISN'T FREE
                    SUPPORT OUR TROOPS

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                    • #11
                      Hawk, I too Salute you and that bag of info you must have hidden in Tennessee... I use 95/5 AR/O2 for spray with .035 and get beads that look like toothpaste, have used 98/2 AR/O2 for stainless 035 on 1/4" and had pretty good results, 2F position, just used a little weave.
                      Thanks Again, Paul
                      More Spark Today Pleasesigpic

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                      • #12
                        Paul,

                        I used to use a 95%argon/5%oxygen until it became hard to get and I switched back to the 92%argon/8%CO2. The 95/5 is really hot and I could go in and out of spray at 23.5 volts on .035" bare wire.

                        Alex and Paul,

                        Thanks for the thumbs up!

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