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AC/DC welder

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  • AC/DC welder

    I have a question can someone tell me the advantages of a ac/dc over just an ac welder? Sorry if it is a dumb question. Curious
    Thanks

  • #2
    Its easier to strike an arc, instead of peck peck peck with an ac you just light it up with dc. Plus some rods are dc only. 7018 ac rod is ok, but regular 7018 runs better on dc...Bob

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    • #3
      dc- deep penitration dc+ reverse less penitration for out of postion ( over head, vertical up, horizatol) ac least amout of penitration used for sheet metal

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      • #4
        Originally posted by link523
        dc- deep penitration dc+ reverse less penitration for out of postion ( over head, vertical up, horizatol) ac least amout of penitration used for sheet metal
        I think you got it backwards? For SMAW, DCEP (reverse polarity) gives greatest penetration. DCEN (straight polarity) gives the least. I almost never need it, even when out of position.

        AC will be in the middle for penetration, but you'll never use it unless you are trying to counter arc blow or something. The electrode selection for DC and its ease to use and less spatter will make DCEP just about all you ever want or need. DC is also much safer in damp conditions when it's easier to get shocked while welding or changing electrodes.

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        • #5
          sorry your right i had it all wrong if you go to education at the top then welding libray then tech tips then arc welding there it is listed all currents an electrons you can use with each setting

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          • #6
            The only thing I can add here is to elaborate on what mac said about blowback. If youre metal is magnatized, this causes blowback and the AC helps combat that. An example of magnatized metal would be something that gets a lot of friction use like a hay elevator.
            Just thought I would add that untill last year all I had was an old Westinghouse 300 amp AC machine that has done a gaggle of welding. If you have an AC machine dont feel that you cant be productive, but if youre looking to buy a welder I would look for something that gives you the options of AC or DC.
            Last edited by burninbriar; 02-20-2006, 02:57 PM.

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            • #7
              Originally posted by aametalmaster
              Its easier to strike an arc, instead of peck peck peck with an ac you just light it up with dc. Plus some rods are dc only. 7018 ac rod is ok, but regular 7018 runs better on dc...Bob
              Not only works better, but also your work doesn't break!

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              • #8
                Originally posted by 2112
                Not only works better, but also your work doesn't break!
                No need to scare people looking to buy the hundreds of thousands of old used AC welders out there. Just as with DC welding, the skill is in the operator, not the machine. There are literally millions of structural welds out there made by AC buzzboxes that are perfectly fine and weren't all that much more difficult to perform.

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                • #9
                  Not trying to scare people. Just saying that some times, you get better results from a DC output. I've always been told that when using E7018 that you HAVE to use a DC output or else you don't get enough penetration.

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                  • #10
                    Originally posted by 2112
                    Not trying to scare people. Just saying that some times, you get better results from a DC output. I've always been told that when using E7018 that you HAVE to use a DC output or else you don't get enough penetration.
                    Agreed. DC is definitely smoother and easier and allows a greater selection of electrodes. Almost always worth the extra money when shopping for a machine.

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                    • #11
                      Thanks guys for all of the info.
                      Joe

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                      • #12
                        DC over AC

                        Just try ti Tig weld with AC.

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                        • #13
                          I Tig weld all day every day with AC!! It is what you use on aluminum.

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