Question on setting up to Weld Aluminum

Discussion in 'Metal Boat Building' started by youngtrout, Aug 31, 2010.

  1. youngtrout
    Joined: Nov 2008
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    youngtrout Junior Member

    I'm in the process of getting set up to weld aluminum. I used to MIG steel a lot in a past life. I'm just trying to get back into it with aluminum.

    Ideally I'd like a good MIG setup with a spool gun. I've been watching the used market for a suitable machine with no luck so far.

    A buddy was telling me that there were spool guns out there to hook up to a stick welder? I have not come up with anything online.

    Stick welders with high amps seem to be a dime a dozen where I live. So I was wondering if anyone has a setup like this and which spool gun are you using?

    Thanks for any help you can give me
     
  2. mydauphin
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    mydauphin Senior Member

  3. skypoke
    Joined: Dec 2002
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    skypoke Junior Member

    young,

    I bit the bullet and purchased a Powermig 300 with push pull gun. Once you get it set up, it's pull the trigger and go. Expensive, but through the course of building a complex aluminum cat, zero wire jams, used two tips.

    Chuck
     
  4. TwoByFour
    Joined: Sep 2010
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    TwoByFour Junior Member

    Constant Voltage vs. Constant Current power supplies.

    Hello Youngtrout,

    As far as I know and according to the wikipedia article on GMAW or MIG, an old school transformer based stick welder is usually a so called Constant Current (CC) machine, whereas the MIG counterpart is a Constant Voltage (CV) machine .

    MIG welding with a CC machine is a great deal different from welding with a CV one. Supposedly CC can work well for MIG welding aluminum but takes more skill to produce good welds compared to welding with a CV machine.

    You can get a wire feeder unit that can be hooked to a CC supply, which monitors the arc voltage and controls the feed rate as to maintain a constant arc length. I doubt getting a CC supply and a wire feeder of that sort would prove to be much less expensive though.

    You can basically hook any sort of wire feeder to any sort of power supply, granted you have the basic knowledge on how to do it, but the welds produced might not be very good. In the past I have stick welded with a MIG machine by fastening the stick rod to the MIG tip with a hose clamp - it wasn't the ideal setup but it worked for the emergency I was in.

    There are of course multi-process machines out there that are made for MIG, TIG and Stick ...I believe some of them even have a plasma cutting option, but the ones that are any good are quite expensive.

    Besides the CC / CV difference, Many of the more modern welding machines have very useful special features / settings for welding different materials, such as arc pulsation etc.

    I recommend that you look at the wikipedia article for further clarification.

    http://en.wikipedia.org/wiki/Gas_metal_arc_welding

    It's been around 10 years since I welded aluminum with MIG and all of it was done with a traditional MIG torch, comfortably at a welding table with a very short torch lead as to minimize problems with the filler getting jammed. Back then I was not aware of the existence of spool guns or such, nor was the guy I was working for. It is definitely possible to weld that way if you keep the leads as straight as possible and use a PTFE liner for the filler wire. It can be hard to keep the leads straight and horizontal if you're welding in awkward positions or using long leads.

    I have never used a wire spool gun myself but I can imagine that it is somewhat useful, especially if you're using long leads. I imagine that buying small spools would be more expensive for you than the bigger ones, though.

    Another alternative is as Skypoke points out, a "push-pull" torch, where the machine's wire feeder unit pushes the wire to the torch and then there is a small wire drive in the torch itself that pulls the filler wire from the wire feeder. Again, I've never used but I imagine this to be a very useful setup. With that sort of a setup you can buy larger wire spools which are significantly cheaper, at least where I live.

    I came across something interesting the other day on YouTube, somone who has been posting videos with general tips regarding welding. He has a website he calls http://www.weldingtipsandtricks.com/ Some of the advice shown and posted there might be of your interest.

    The welding machine makers (Lincoln, Hobart, Miller ...etc) also have some useful information on their sites, if you care to look. Otherwise, there are plenty of information in various places online, which you can find with the search engine of your choice.

    Hopefully my ramble will be of some help to you.

    Carl.
     
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  5. youngtrout
    Joined: Nov 2008
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    youngtrout Junior Member

    Thanks guys, I'll keep my eyes open in the used market. I have looked at the ready welder. They do get decent reviews, my only real hang up there is from ready the specs, it does not look like you have much option in terms of wire speed, you either put it on steel or aluminum.

    Ideally I'd like to just find a hobart, miller, lincoln that I can afford here locally
     
  6. pdwiley
    Joined: Jun 2008
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    pdwiley Senior Member

    Huh???? I've got a Readywelder and it has a wire speed control. In fact that's its only control, changing that automatically alters voltage/amperage.

    Never used mine for ally so no comment there.

    PDW
     
  7. youngtrout
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    youngtrout Junior Member

    Maybe I read the write up worng, I thought wire speed was set,,,,,,,,I'll look it up again

    Thanks for pointing that out
     
  8. TwoByFour
    Joined: Sep 2010
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    TwoByFour Junior Member


    Hello pdwiley,

    Having experience using the Readywelder, would you consider it as an option to build an entire boat with it, especially an aluminum one?

    To me it looks rather bulky to hold and I can imagine it being quite annoying or even impossible to operate in tight spaces. Perhaps one would have the same problem with most spool guns or push/pull torches?

    At least if you have a MIG machine or a Stick/TIG power supply with a wire feeder, you can always swap over to a less bulky traditional torch if needed, while you can't do that with the RW...you're just stuck with it, unless of course if you're just using it as any other spool gun with a MIG machine.

    Another concern is duty cycle - how does the ReadyWelder torch handle high output for long periods, is it likely to overheat and cause problems?

    I am sure the RW is a great unit to have for emergencies and contractors who do not do much welding but need to weld occasionally, but I am doubtful of it being a unit you would be happy with using extensively on big projects like building an entire boat.

    Feel free to tell me if I'm wrong. :)

    Carl.
     
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  9. pdwiley
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    pdwiley Senior Member

    I bought my Readywelder as a backup device really so it hasn't seen a lot of use as compared to my stick welder. Enough so I am familiar with its capacities though.

    Bulky, yes it is. No more so than any spool gun and less so than a lot but having that wire spool in the handle does add bulk and weight. The gun itself is pretty light. I have a conventional 150A MIG welder on loan and its gun is a lot easier to get into position.

    I run mine off of a DC power supply - I have a big AC stick welder and an AC-DC box attached to it. The problem in doing this is, as supplied, the Readywelder needs a separate power feed for the electronics as the stick welder voltage isn't stable enough. My Readywelder came with a 110V-24V transformer which was useless as I'm on 240V. I tossed it and used a switch mode power supply without problems. The gun electronics aren't super fussy, anything between 12V and 40V is fine. Note that this only applies if you're running the gun from a constant current supply, if you're using say 2 of 12V batteries in series you don't need to do anything about providing the gun electronics a separate supply. This supply incidentally is only for the wire feed control, nothing to do with the current going to the tip.

    The small spools of wire are considerably more expensive than buying 5 kg or 15 kg spools.

    Duty cycle - don't know. I would not be happy using it for long periods on high wire feeds and a lot of heat though but keep in mind that I was running 6mm E7024 electrodes when welding on the keel so I like to be able to lay down a heavy bead in a single pass if I can. The Readywelder is capable of welding 10mm steel in 3 passes using 0.9mm flux cored wire provided you do a proper V prep (which you should do regardless). It can get the heat into the work so I have no issues with getting cold welds as you can do with the 0.6mm wire that lightweight welders use. I haven't used solid wire so I can't say if it can handle 1.2mm but I don't think you can buy this thickness in the 1 kg spools anyway.

    I wouldn't use it for building a complete boat, particularly ally where you need even higher heat than steel. It may be capable of the task and the shorter distance to push soft wire would be a big advantage (its lead from the power supply is 3.6m I think, maybe longer). I think you'd be better off with a conventional MIG welder and figure out a good way to move it about. The newer MIGs with inverter power supplies seem to be more or less portable in the 250A to 300A output sizes that I'd consider minimum for welding 6mm ally. Duty cycle on a lot of single phase MIG welders is pretty pathetic at their max rated output, sometimes 10% which is a joke. The Readywelder is a lot better than that provided you've a big power source feeding it. My stick welder is rated for 250A at 60% duty cycle as is my 3 phase MIG welder.

    Nearly all the welding on my boat has been done with 2.5mm E4111 rods and you could get by with a 160A DC shoebox welder for those. As I said the exception was the keel where I used heavy iron powder rods. I've swapped over to using the spool gun and a conventional MIG now I'm welding the hull plate to the frames as it's a lot easier & lighter to weld overhead with a light gun and flux cored wire. I may swap to solid wire when I ship my big MIG and a couple of flow meters down from my Sydney house.

    The Readywelder is going in the boat when I go sailing so I can do some welding if I need to regardless of where I am, as long as I've got a couple of decent 12V batteries.

    If you can afford to have a MIG for your main fabrication welder and a Readywelder as a spool gun and for repair use later, by all means do so. It's a nice unit and works well. It wouldn't be my first choice for building the boat in the first place however, if I could only have one welder.

    PDW
     
  10. pdwiley
    Joined: Jun 2008
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    pdwiley Senior Member

    My gun definitely has a wire feed speed control. Inside the gun there's a tension control for the wire feed rollers that has different settings for steel & ally but that's the tension setting how hard the roller pinches down on the wire so you don't deform the soft wire, not the speed feed.

    There are no other controls. You swap between electrode positive & negative when you hook up the leads depending on whether you're using solid or flux cored wire, that's it.

    It's a nicely engineered unit but as I've said in another post, it wouldn't be my first choice for building a complete boat regardless of whether it was in steel or ally.

    PDW
     
  11. thomt
    Joined: Dec 2010
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    thomt thomt

    Miller has what you want. Works great, not inexpensive.
     
  12. kiwihere2
    Joined: Mar 2011
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    kiwihere2 Junior Member

    thomt is rite,miller. the only thing cheap about boats and welding is nothing.
    the cost of a new machine divided by the rest of your life is a very resonable price.
    ive owned a Esab migmaster 250 for 15 years paid around $2000+.
    $2000 divided by 15years= 133/year and its paid for its self many times.
    buy new, kiwi
     
  13. PSG-1
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    PSG-1 Junior Member

    Get a Miller Spoolgun, and a power supply like a Regency 250, you won't be sorry.

    As mentioned earlier, stick welders are constant current, where MIG is constant voltage.

    That said, I have "paralleled" a stick welder to a MIG welder, to gain more heat input, and it did work.

    But I think the constant voltage of a MIG power supply provides a more stable arc, etc.
     
  14. scott hightower
    Joined: Jul 2010
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    scott hightower Junior Member

    A spool gun is handy but I use a short lead without a spool gun and I have not had any problems.

    Just be sure to keep the lead as straight as possible. You also need to use 100% argon as a shielding gas.

    Scott
    welders360
     
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  15. PSG-1
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    PSG-1 Junior Member

    Correct. Also, the use of a teflon liner in the lead for the MIG gun will help prevent bird-nesting a little bit. That and the fact that a steel liner can contaminate the filler wire, as well as the fact that it shaves off pieces from it, which eventually jam that liner, and it causes major bird-nesting.
     
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