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Old stick welder needs twice the current to burn rods?

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  • Old stick welder needs twice the current to burn rods?

    Have a very old Airco EasyARC AC/DC 250 stick welder and was welding some 4" to ~3" pipe to make an anchor to cement in the ground to secure my trailer. Had to turn up the machine to like 225 just to run 1/8" 6010 and left the settings for 3/32" 7018". By no means was burning too hot since 6010 would stick every now and then when starting the arc. Even practiced a little up hill and down hill with the 6010 and filled the massive gaps on either side where the 4" pipe over hangs the ~3" (did no saddles). Then practiced some up hill 7018 cover passes and was getting some pretty nice beads for not picking up a stick welder, but once every few years.

    The welder is so old that it was the first on only electric shop welding machine my dad used when he started his own welding business. I'm thinking he must have got it used back in late 70s early 80s. I first learned to stick weld 5P with this machine when I was 7. So it's sort of important to me to keep it running. He told me they stored it away in the mid 90s since we moved and the new shop had 2 3phase machines. So he wasn't sure if it worked still.

    I used it in 2014 to make a door frame out of angle iron and cattle panels for my hunting ground blind, but noticed it wasn't wanting to run 6010 for some reason, so I had to use either 6011 or 6013 I can't remember which I used. It seemed to weld normal then at around 120amps.

    Saturday I couldn't even get it to make an arc flash with the amps at 140 with the 1/8" 6010, so I just kept walking back and turning it up and then repeating the process until it would hold a decent arc. That put me at about 225 amps on the dial to run the 6010 1/8" and 3/32" 7018.

    Anyone ever seen a welder need to be turned up like this?
    Hoping someone could lead me to solution to this problem...?

    I haven't had the time Mon-Fri, but I have Fluke meters and a DC clamp meter that I'll probably check the output voltage and current with.

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  • #2
    First, thank you for being specific in the subject line.

    That machine has no low/high range settings that I know of, so that's weird. First test is definitely the DC clampmeter while welding. Switch machine to AC and do the same testing, also. Would a bad diode in the rectifier maybe cut off half your current on DC?

    What's your polarity setting, and verify that your electrode and work leads are in the correct sockets for it. You want DCRP (Reverse Polarity, which is Electrode Positive).

    What is the input voltage rating of the machine, and what voltage are you feeding it? Might it only be being fed half the voltage?

    I found pics of that machine, but can't read the label well enough:
    Last edited by MAC702; 02-01-2017, 12:55 PM. Reason: I corrected the polarity. I had a brain fart because TIG has been in my head for so much these past few days.


    • #3
      Are you sure it is wired for the voltage you are using? I would check the on/off switch as well to be sure you are not losing 1 side of the 220v(I assume that's what you are using)---Meltedmetal


      • #4
        Thank you for the suggestions. Here is a better look at the name plate info. The welder is powered by the same 240Vac that I run my Millermatic 252 on. I just unplug the Mig and plug in the huge extension cord (cord was made for running RVs) and plug the welder into that.


        • #5
          I am running the Airco in DC+ for the 6010 and 7018. So DCRP (reverse polarity).
          The machine has the labels Work on the left which is where my ground lead is and my stinger is connected to the Electrode side on the right.

          I didn't think about checking if the machine has lost one of the 240V legs, I will check that at the switch next chance I get.
          The diodes, I'll have to search for since they weren't obvious the last time I had it opened up.

          It really is a mechanical marvel inside! Its amazing how they did things so long ago where things mechanically engage to make contact. Polarity:

          E6010: DCEP
          6011 - AC or DCEP

          DCEP: DC, Electrode Positive (reverse polarity) has the most weld penetration


          • #6
            Originally posted by clint738 View Post
            ...DCEP: DC, Electrode Positive (reverse polarity) has the most weld penetration...
            What's funny is I was out in the shop and had a light bulb break over my head, and realized I'd put in the wrong polarity info. I was actually on here to correct it, but you noticed it first. Darn!


            • #7
              Originally posted by clint738 View Post
              Thank you for the suggestions. Here is a better look at the name plate info...
              So it is possible that there is a jumper configuration inside that might be set up for 460/480 V input, though that might be the first time I've seen that for a single-phase machine.


              • #8
                Good point, I didn't think about the 460/480 possibility on the machine. I'm positive the shop they used it in had just 240V, but we also had some mechanic do all guys who thought they could wear the welder hat at times and then change to the electrician hat.

                I'll have to see if I can find any details about the internals and see if maybe they had it wired wrong.


                • #9
                  If it isn't obvious, take a picture of the jumper configuration, and we'll brainstorm it.

                  Does it have a fan?


                  • #10
                    it does have a large fan.


                    • #11
                      Here are some internal pics

                      There are quite a few there.

                      I found in the bottom of the machine a cap.

                      I'm not sure what the porcelain looking component is sandwiched between 2 heat sinks?

                      Right above the heat sink is a rather simple looking board, but with the yellow capacitor having 1 leg broke off from the board.

                      I think it is fascinating how these transformer based machines work.
                      At first I thought maybe this part looks like a large power resistor, but not sure. Reminded me of how some inverter designs have coils connected to the Positive terminal to allow for running 6010 rods.

                      When I first opened it up, I was amazed that this thing even had a circuit board with integrated circuits chips.
                      No special coating or sealant on the board. Just exposed to the dust and everything else in the environment.

                      It would be awesome if somehow I could really pin point the year this thing was made. Would just be cool to know for when I pass it on some day.


                      • #12
                        Sorry I didn't get a chance to take voltage and current measurements yet.... was building on my safe box with the limited time I had Saturday.

                        Getting the measurements is my goal next chance I get. Figured showing the pictures here someone would recognize that device with the heat sinks around it? I thought possibly the diodes, but it I've never seen any like that before so I wasn't sure.

                        Also thought maybe a thyristor, but wouldn't think they'd have that in a welder this old?
                        Last edited by clint738; 02-13-2017, 04:05 PM.


                        • #13
                          Can you get the serial# off the front control panel and post it here?looks like on the board there are two burn marks on the two vertical cap on the bottom right ?
                          mite be able to get a manual on it if it crosses with miller machine .D


                          • #14
                            These two guys


                            • #15
                              Originally posted by D Auger View Post
                              These two guys
                              Those are wire wound resistors, not capacitors. Could be bad, but they are high wattage and it is not unusual for them to discolor with age as they look in the picture. One appears to be 3000 ohms (Greek letter omega after the number). Couldn't see the pic very well on my phone. Would have to unsolder one end from the board then check with an ohmmeter.