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  • new toy - finally got a MIG welder

    And to make this On Topic, I have to machine a few parts to adapt tab A to fit slot B, hehe.

    Garage sale less than half a mile from my house a few days ago.
    I picked up an Airco DIP/STICK welder for dirt cheap. It came with a Tweco gun/hose instead of the original. That will be nice, but I need to machine an adaptor which will amount to 5 separate parts, but it should be fairly easy to pull off all together.

    Last night I wired up an appropriate outlet in the garage and tried the thing out in "stick" mode - Seems fine. Tthen shorted the trigger contacts in "MIG" mode and the feeder motor and control all appears to work just fine, which relieves my main worry. Seems to be plenty of power - it burned a hole in some scrap 1/8" in nothing flat with the amps set up too high. I'm going to clean it up today and start working on the adapter stuff.

    I always had access to MIG where I worked over the years and since my current job doesn't have any welding equipment at all, I've been kind of jonesing. I've never run across a deal like this before either, so I feel pretty good about getting it. It even came with a big shielding gas tank too.

    Questions:
    1) The tank needs to be refilled of course. Anybody know if the age of the tank is an issue at the supplier? I know they like to get you to pay for a test, but I don't know what their druthers are for it. Does the type of gas that it contains affect their need to test? Anybody know what the threshold for age of the bottle is before they need to test them first? How much is a refill for a mixed shielding gas these days anyway (it's about 5' tall)?

    2) The connector end of the Tweco is brass rather than copper (a little surprised by that, but not stunned). I'm assuming I can use brass to make my adapter too, and I have scraps of that in the pile. That should work fine right? If copper was cheap I'd use that instead just to be retentive, but it's not at all cheap and I don't have any so I'm going to avoid that unless somebody holds a figurative gun to my head.

    Now the juicy one...
    3) Seems like the ideal situation is for the current to flow from the wire only out at the working end of the tip of the gun to the work. In reality, the wire is "hot" whenever the trigger is pulled if the wire is fully threaded through to the gun, so the feed mechanism is then effectively hot too. So I should assume that the feed mechanism (pinch rollers, etc.) is insulated from ground and don't have to consider whether my adapter is insulated from the feed mechanism, right? It looks like the attachment of the original was directly connected (electrically) to the feed mechanism anyway, so I'm not changing anything. But I never considered this before so I just thought I'd ask.

    Thanks.
    and Woohoooo!

  • #2
    Funny.... I got one today too!

    1) The year that it was last tested is stamped on the top of the bottle. I bought a bottle yesterday from a local welding supply shop, and when I checked it at home I found it was last tested in 97. I did not know how to read the code till I looked it up in the web. The test is generally good for 10 years. That means I will pay for a test when I get it refilled. I'm not sure if I should be upset about that yet.

    I read yesterday that CO2 is bottled at a lower pressure than argon, so the bottle that passes the test for argon can be used for argon or argon mix or co2.

    2) Copper (in general) has lower resistance than brass, but that reisitance may be part of the design.

    3) The feed mechanism on mine is made of plastic, so it's insulated there, but the reel of wire is definitely hot. Electricity knows nothing of direction in this context. It will flow from source to ground by whatever path has the least resistance, but when presented with two paths it will go over both, with the current proportional to how low the resistance is in each path.

    If properly insulated, the wire extending from the gun is the only path available for the current to travel through.

    Dan
    At the end of the project, there is a profound difference between spare parts and extra parts.

    Comment


    • #3
      Congratulations!

      I occasionally see cheap gasless MIG welders for sale in LIDL which use what I think is called fluxcore wire. I am no welder but keep get a nagging sensation that i should get one and learn.

      Are the gasless types worth it and are there any drawbacks, ie the wire costs 3x more than standard and the gas is dirt cheap?

      Comment


      • #4
        The gassless ones (FCAW or flux-core) are messy. There is a lot of splatter. This is because the flux is inside the wire and is vaporized by the heat to create a cloud of inert gas. This cloud protects the weld from oxygen so it gives a better joint. By splatter I mean little balls of melted metal that shoot all over the place. By mess I mean a glassy slag that you have to chip off before painting.

        The cheaper ones often have just a few "heat" (actually amp or power) settings. It takes different amounts of power to get a really good weld on 16 gauge than it does to weld 18 gauge. To high and you melt through. Too low and you don't melt the metal deep enough. My Harbor Freight model 100 is FCAW has two power settings; high and low. It works, but it isn't pretty and I doubt I could get a water-tight weld with it.

        You can not cleanly weld aluminum with FCAW. On the other hand, FCAW is often suggested for use outside where the breeze might blow away your gas.

        Gas is not cheap. You have to buy or rent the tanks. The fill for enough gas to work for 4 hours is $50 at my local shop. The 40 cu ft tank was another $100. In my garage that will probably last a year or two, or until I forget to close the valve.

        Gas (GMAW) has very little splatter. With the right gas and wire, you can even weld stainless and aluminum. With gas there is often little to clean up. A gas unit can usually run flux core too.

        MIG is easy to learn. Practice makes the difference. I just bought a gas model to replace my flux core one, if that's an indicator.

        Daniel
        At the end of the project, there is a profound difference between spare parts and extra parts.

        Comment


        • #5
          Originally posted by DickDastardly40
          Congratulations!

          I am no welder but keep get a nagging sensation that i should get one and learn.
          Welding is an excellent complement to machining. Machining removes stock. Welding adds it back on. There are things you can do with a welder that are very expensive/time consuming to do any other way. For instance, I can make a set of supports for my DRO scales by milling it from a BIG block or aluminum, or by screwing several smaller pieces together (remembering to leave room for the screws the second time) or by welding a couple of lengths of strap steel to the appropriate configuration.

          A lot of that can be done with brazing too, but welding can be much stronger.

          The other interesting thing that works with welding is the idea of 'tack welding' something bulky to a fixture so you can work on it, then grinding away the weld when you are finished.

          Dan
          At the end of the project, there is a profound difference between spare parts and extra parts.

          Comment


          • #6
            Originally posted by danlb
            Gas is not cheap. You have to buy or rent the tanks. The fill for enough gas to work for 4 hours is $50 at my local shop. The 40 cu ft tank was another $100. In my garage that will probably last a year or two, or until I forget to close the valve.

            Daniel

            To keep costs down, if you're only doing steel, CO2 is a workable gas, its the stuff that pubs use to pump/froth the beer with. I get a big bottle from my local for a good tip to the owner and it lasts about two years.

            It does give a little more spatter than argoshield or other gases but for the cost it cant be beaten.

            I too found fluxcore messy but good for outdoor stuff, its costy though.
            If it does'nt fit, hit it.
            https://ddmetalproducts.co.uk
            http://www.davekearley.co.uk

            Comment


            • #7
              The dipstick is a pretty light machine. I think around 160 amps. The guy that designed them used to live around here so I have heard. The current control system can be problematic.

              Tweco sells an adapter that will do what you want for about $35-$40. I wouldnt mess around with making one.

              The difference in resistance between a little piece of copper and a piece of brass is so negligible you couldn't measure the resistance without special equipment.

              Dont mess with CO2. Just get the mix. The slope on these machines are intended for mix and I dont think you can change it on this machine. You could on its bigger brother the DipCor 300. As for refills its a totally regional thing. Here you just drop off a bottle at airgas and unless you specifically want that bottle back they just swap it out with another. They dont worry about hydro. The ones that need hydro are sent to the hydro facility. The cost is all worked into the cost of the gas. Unless you have a special bottle you will never pay for hydro as an line item.

              BTW, Dip on these machines is what Airco called short circuit welding. The wire "Dips" into the weld pool.

              Oh, yeah, the place to go to for parts and manuals is Arc Products in San Diego.

              Comment


              • #8
                Id say gas and fluxcore probley cost about the same after all is considered.
                Gas however is MUCH nicer to work with. much less mess, much less smoke (flux core has sooo much smoke you can NOT see the weld puddle)

                Flux core leaves glass 'slag' all over the weld and brown dirt (smoke debrie) all over. has to be chiped off with a hammer/pick/needle gun.

                That said, my brother (professional dump truck/large truck welder) *swares* by 'double shielded' wire, this is some kinda weird ass flux cored wire thats supposed to be used *WITH* gas, And apparently it will even do nice welds on dirty metal.

                But I think if you just take the time to grind/wirebrush (get a knoted wirebrush attachment for angle grinder), gas is just as good for any HSM.
                Play Brutal Nature, Black Moons free to play highly realistic voxel sandbox game.

                Comment


                • #9
                  Dual shield wire is great. But a 30 lb spool is something like $130 last time I checked. This is for Lincoln 91K2H. My dad even welds cast iron with this stuff. Beautiful welds. Burns right through mill scale and the like.

                  Comment


                  • #10
                    Originally posted by DickDastardly40
                    Congratulations!

                    I occasionally see cheap gasless MIG welders for sale in LIDL which use what I think is called fluxcore wire. I am no welder but keep get a nagging sensation that i should get one and learn.

                    Are the gasless types worth it and are there any drawbacks, ie the wire costs 3x more than standard and the gas is dirt cheap?


                    FWIW, All MIG welders use gas, that's what the "G" is in MIG. A flux core welder is not a MIG welder until a gas kit is added.

                    Comment


                    • #11
                      Reference to your tank needing hydrostatic testing. Your local gas supplier may or may not trade out on another tank. It depends if the tank has a stamped collar on it from a competitor. Some shops are picky when it comes to that. If it has no collar on it and appears to have been a privately owned one they'll probably swap out but hit you for an additional $20-$35 to cover the hydro test. All depends if they want your business or not and in this economy they should treat you right.

                      Comment


                      • #12
                        Thanks for the tips guys.
                        Especially Macona, so sounds like he's been around one of these before.
                        I'll check with Tweco. Fer $35 It's about a wash comparing my time to just buying one. I'm broke, but more short on time these days really.

                        I had the thing apart today to make the adjuster plate slide smoothly between the coils. It was binding up pretty bad, but now it's smooth as silk. I don't know how the current control could be problematic since it works about the same as any other mechanical current control, unless it's the binding in which case I've taken care of that.

                        I haven't looked at my TIG gas bottle for a while, but IIRC it is just the 75/25 mix, and the one that came with the welder is too. I was talking to a buddy today and he said that lately they are good about just exchanging bottles when you go in for a refill, so that's changed a lot since I did it last. A few years ago they wanted me to show papers proving I owned my acetylene bottle. I talked them out of that hassle but expected it to just get worse over time. I'm glad to hear it went the other way. That was just a pretty stupid idea to hassle customers over leases/owning/finding bottles.

                        Well after the cleaning and fiddling with the adjuster plate, I tested it in stick mode and tried a bead. It works fine. Yaaaay! For heavier welding I'll just use my 300A Lincoln (which welds close to as nice as a pipeliner), so this little Airco should be just fine for my non-heavy-duty welding - most of what I do anyway. I find stick welding much easier to deal with when doing heavy stuff. The tendency for sticking is almost zero and the slag often peels itself at least mostly off on its own. But I don't weld heavy stuff all that often so I'm going to enjoy having a MIG welder.

                        Thanks again for the replies.

                        As for my reply to other posters:
                        Comparing flux core with gas, personally I wouldn't even consider it. The tanks vary in price so you can save up a little and get one to suit your budget and usage. To me it seems useless to have flux-cored wire feeder because most of the beauty of MIG is the lack of slag hassle. It's true indeed that those little flux-core, gasless wire feeders are not MIG. They are just wannabees. Better than nuthin' but not near as nice as MIG.

                        I would recommend getting into welding a bit somehow. It's just one of those things like owning a truck, in that once you can do it, you can't imagine doing without it.

                        Comment


                        • #13
                          I used to be a service tech at Airgas.

                          That was one of the problems. Binding in the slides. Also things tended to vibrate loose over time.

                          Comment


                          • #14
                            Flux-core wire is run electrode negative, solid wire used with CO2/Argon mix is run electrode positive. Thats why the wire feed assembly has the ability to switch polarities. Be careful your gas supplier doesn't try to steer you into more expensive mixes like Stargon. It's unnecessary.

                            Radkins, correct typing faster than thinking.
                            Last edited by reggie_obe; 05-09-2010, 06:02 PM.

                            Comment


                            • #15
                              Originally posted by reggie_obe
                              Flux-core wire is run electrode negative, solid wire used with CO2/Argon mix is run electrode negative. .


                              Flux core is indeed run electrode negative [straight polarity] but solid wire with gas shielding is run electrode positive [reverse polarity].


                              From reading the rest of your post I think that's what you meant to say?

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