Ask your WELDING questions here.

Discussion in 'The Garage' started by KTM640Dakar, Mar 5, 2007.

  1. KTM640Dakar

    KTM640Dakar Motorsick

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  2. JDLuke

    JDLuke Ravening for delight

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    Hey, KTM640Dakar, thanks for doing this. I do a (little) bit of hobby welding on my 3200HD, and it's good to have more information available.

    My question goes kind of goes back to some of the earlier posts in this thread, regarding extension cords and the like. I guess my basic question is: If I were to take heavy AC BX-protected wire, and build an 'extension cord' out of it, where would the drawbacks be for powering my welder?

    I ask this because as it stands right now, I have a circuit breaker in my basement, tied to the mains. About 45 or 50 feet from this, at the end of another heavy gauge cable is a subpanel in my garage, with the 20 amp circuit breaker for the welder. However, it would, so far as I know, have been quite possible to make it a direct 50 foot run from the main panel to the outlet, right?

    So how much harm would there be in having 30 or 40 feet of, say, 12 gauge solid-core wire in between one outlet and an extension outlet?

    The REAL reason I want to know is that I have a swing set with steel tube legs in the backyard, maybe 40 feet from my garage. Due to an unfortunate landscaping incident, one of the legs has a big chunk of metal missing, and I'd like to weld a sleeve over it... I've been extremely reluctant to even try using an extension cord, but I can't help thinking about the fact that there are many hundreds of yards of copper wire between my outlet and the actual power source already.
  3. furiousfart

    furiousfart Been here awhile

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    You can allways go to the homedepot or local supply house and get some SO cord. SOW is listed for wet and damp locations and is a heavy duty use cord. You said it is a 20amp breaker, then get a #10 cord, if there is going to be a signifigant length to the cord and then get a set of ends that match your current set up and you are good to go.
    The AC really isn't designed to be used as an extension cord outside or in, plus being solid it won't like to wind and unwind too much.
  4. JDLuke

    JDLuke Ravening for delight

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    FuriousBrokenWind,

    I guess what I'm trying to do here is determine where the dividing line between sensible and stupid is.

    If I were to bury some conduit a couple of feet underground and pull wire through it, from the garage to over near the swing set, and install an outlet, that would be perfectly OK, right? But an 'extension cord' isn't OK... My thinking is that at SOME point, an extension has got to be heavy enough to carry the required current, and that point should roughly correspond to when the area of the wires equals the area of the wire one would bury if hard-wiring a circuit.

    It sounds like the cable you're talking about is more like what I had my electrician put on my 220V table saw when he was reworking my basement wiring. Heavy gauge cord with thick black insulation. Essentially I'd be custom-fabricating a to-spec extension?
  5. KTM640Dakar

    KTM640Dakar Motorsick

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    What I really would avoid is the typical extention cord that is made out of small strand copper wire that is too light. A good extention cord would be the same copper conductor that you would use to wire a house that utillizes solid copper as a conductor.

    The real reason that an extension cord is a problem is that most homes use 15 or 20 ampere circuit breakers and when you turn a welder to it's maximum output the current draw required for the welder to give you max output may exceed your circuit and trip the breaker. Adding an extension cord to a welder that is undersized will trip the breaker sooner due to the extra resistance of the extension cord.

    Of course you can still try it and the worst thing that will happen is your circuit breaker will keep tripping off and cut the power.

    I do have an extension cord for my 230V MIG welder. It is made out of heavy copper wire that is heavier than my in house wiring. At 230V a 30 Amp breaker is perfect for my welder and I have never blown the circuit. The extention is about 30 feet long. The longer the cord the bigger the conductor needs to be.

    http://www.interfacebus.com/Copper_Wire_AWG_SIze.html
  6. JDLuke

    JDLuke Ravening for delight

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    Thank you.

    I was beginning to have weird thoughts of solid copper bus-bars. :D

    I'm going to give it a try. I'll get the heaviest damned extension I can find or fab and go for it. I really need to get that leg fixed before it rusts out completely, we've had a lot of rain lately. Raining right now, as a matter of fact.

    From the chart you posted, it looks like 10 gauge can carry 14.8 amps safely, but 8 gauge can carry 23.6, so unless I am missing something fundamental, I ought to be OK with 8 gauge wire out to a distance rather greater than I need.
  7. JDLuke

    JDLuke Ravening for delight

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    OK, another question.

    I have not as yet tried welding aluminum, but it seems that my machine (as mentioned earlier, the WeldPak 3200HD) is capable of it with an accessory kit:

    http://mylincolnelectric.com/Catalog/equipmentdatasheet.asp?p=2127#disclaimer

    I have a few questions:

    First, is it generally worth trying to weld 6061 aluminum with this box, regarding weld quality and material capability?
    Next, is it an awful, time-consuming switchover between steel and aluminum? It looks like a new drive wheel, and a new liner... Does that mean I have to thread the whole kit through the hose? And then swap back for steel? That would get kind of old. I am beginning to wish I hadn't purchased a rig until the new ProMIG came out that can take the spool gun.

    Thanks a lot!
  8. myblubeemer

    myblubeemer MOA, IBA

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    I a welding noob. Took a MIG welding course recently from the local Industiral School. I'm looking to buy a welder and understand Lincoln now makes a MIG unit that also will weld aluminum kinda like TIG. I saw it on Two Guys Garage on Speed. It had a "gun" with the feed in it. I would like to know if you think this would be a good home unit for general bike and repair type welding and what your recommendation would be if not. Thanks,

    Joel

    Dallas, TX
  9. CR_TurboGuy

    CR_TurboGuy Iowhat?

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    Recently while taking off my home-made Pelican racks, I noticed that the turn signal mount broke and half the tab came off in my hand. My question is if I disconnect the battery from both terminals, can I weld the tab back on w/out tearing the bike apart to get the rear sub-frame off?

    --JOsh
  10. KTM640Dakar

    KTM640Dakar Motorsick

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    Welding Aluminum using the MIG process.

    MIG welding is a wire feed process that uses drive rolls to push the welding wire. MIG welding with steel wire it is quite easy and is sucessful because steel welding wire has plenty of collum strength that allows the drive rolls to easily feed the wire through the welding gun conduit. This conduit or "liner" is inside the gun and guides the wire to the end of the gun where it exits the contact tip (copper tip) of the gun. Because steel wire is strong it is easy to push through a long liner.

    Aluminum wire on the other hand has a relatively low collum strength. This causes the aluminum weld wire to sometimes buckle inside of the liner. (often refered to as trying to push a wet noodle through a tube) If the wire does not feed at a constant rate then you will experience problems with the wire burning into the copper contact tip (burnback). As soon as the contact tip gets melted by the arc it stops the wire from feeding and fuses into a melted mess. At this point all welding stops and you will have to replace the contact tip. Also when this occurs you may have what is called a "bird nest" in the wire feeder. This is caused by the wire stopping at the tip while the drive motor is trying to push it out and it tangles and causes a bird nest.

    This will all need to be cleaned up and straightened out before you can get back to welding.

    With most MIG welders you can help solve this problem by using a liner that is made out of a low friction material like teflon. Most gun liners made specially for aluminum are made from teflon to reduce friction and help get the aluminum wire smoothly fed out of the gun. This improves the feedabilty of aluminum wire. Also most drive rolls for steel wire are vee grooved and the ones for aluminum are u-grooved. You use a u-groove set of drive rolls for aluminum wire so that you can get a better grip on the wire, again to help with feedability. The last trick is to keep the MIG gun as straight as possible with as few kinks and turns in the gun itself as possible. This also helps reduce the friction on the aluminum wire.

    This is why special equipment is designed for MIG welding aluminum to overcome these feed problems. A spool gun is for welding aluminum and the roll of wire is right on the gun so it only has to push the wire a couple of inches instead of 10 or so feet depending on how long your conventional MIG gun is.

    You can convert a steel MIG gun to weld aluminum and most manufacturers have kits available to do this. In the kit you will recieve drive rolls, a plastic gun liner, aluminum contact tips, and sometimes a set of lighter drive roll springs so that the tension on the drive rolls is less to reduce bird nets that may occur.

    You will also need 100% Argon shielding gas. If you are going to use a MIG gun also use 5356 Aluminum welding wire. 5356 has a higher tensile and collum strength than 4043 Aluminum welding wire. The extra strength will help with feeding.

    Better yet buy a spool gun for your MIG welder. All of the Lincoln Power MIG units have spool gun capability. In fact the new Magnum 100SG Spool gun will fit both the Power MIG 140 and 180 MIG welders. This spool gun is $200. A mig convertion kit is $100. The frustration saved by using a spool gun will easily offset the $100 difference.
  11. KTM640Dakar

    KTM640Dakar Motorsick

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    Yes!

    Clamp the ground clamp from your welder close to where you are welding and at least disconnect the negative connection to your battery.

    Remember that the flow of current that goes from the welding torch to the ground cable should be as short of a distance as possible. Try not to clamp your ground cable too far away from where you will be welding and avoid touching wiring harnesses and battery cables.
  12. KTM640Dakar

    KTM640Dakar Motorsick

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    It will do it but your welds will be small. Set your machine as the label recommends. There is a sticker on the inside door cover that gives you recommended settings for welding. This chart is excellent and rarely do you need to vary from the published chart recommendations. The kit is for aluminum only. You will have to switch it out if you want to weld steel but it is not a very hard change over. The steel wire will contaminate the liner if you don't.

    Lincoln also supplies 4043 spool of wire with the kit. You may want to also get a spool of .035 5356 wire too. The 5356 is slightly stronger and will feed easier. You will notice a little more black soot on your 5356 verses the 4043 aluminum wire chemistry.

    Yes the Power MIG welders solve these aluminum problems.
  13. KTM640Dakar

    KTM640Dakar Motorsick

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    Yes this is the gun.

    http://www.mylincolnelectric.com/Catalog/equipmentdatasheet.asp?p=42749


    If you have 115Volt power then use the Power MIG 140. If you have 230Volt power then choose the Power MIG 180. For aluminum always pick the bigger machine if you can afford it. They both use this spool gun.
  14. JDLuke

    JDLuke Ravening for delight

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    Thanks.

    I wonder if I can talk my wife into understanding why I need a second rig, dedicated to aluminum work! :rofl
  15. Poolside

    Poolside Syndicated

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    <BR>
    That seems silly. In a such a 'wire birdnest' situation, a drive control could easily stop the drive rollers from feeding wire. Or even reverse feed. The basic ability would cost essentially nothing to include.

    Teflon liners are expensive and not as good as PE. The two highest grades of Poly Ethylene have lower friction and are more durable than Teflon, at a fraction of the price.

    I'm not dissing welders, or welding. I wish the industry wasn't contorted so heavily by manufacturers. I mean, it's difficult to have respect for such an extreme level of marketing-department-driven design.<BR><BR>
  16. KTM640Dakar

    KTM640Dakar Motorsick

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    The only thing that stops the drive rolls from rotating is your finger on the gun trigger.

    Poolside have you ever welded?
  17. Poolside

    Poolside Syndicated

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    Right, the old POS design being what it is. A few cents of electronics can be added to the wire drive and allow a long list of essentially free features. Stopping a wire birdsnest before it starts is only a single example.

    Enough to understand the state of the industry.
    <BR><BR>
  18. krampus

    krampus get lost

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    OK, the saga continues. My brother-in-law blows me off and decides to go to Spain for a few weeks and leaves me to my own devices...he did make a large patch with the proper rolled bead in case things didn't go well. After a couple of tries and a ton of grinding, my buddy and I get all the holes welded up. The first attempt we thought was OK...it wasn't. We weren't shy with the heat the second time and it took pretty darn well...thank you Lincoln.
    [​IMG]

    So now, I've got to deal with the pin-holes, most of which I'm convinced are simlpy dimples after grinding . None-the-less, I've decided to try to lead them up. Eastwood has a kit with an instructional DVD. I'm already in over head. Who knows lead work? School me.

    I'm off to fish out the slag.
  19. Poolside

    Poolside Syndicated

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    With any luck, that's exactly where the pinholes came from.

    As far as lead goes, the trowel on semi-molten lead with a wood spoon method is fine for the rough surfaces.

    To seal the pinholes before that process though, a good clean, flux, and tin should work.
    <BR><BR>
  20. krampus

    krampus get lost

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    Yes, the tank needs to be tinned first in order for the lead to take, as I understand it. You are saying that the tin will(can) actually do the job of sealing up pinholes. So here's a stupid question, since the welding only caused the slightest warpage in an area that is not easily seen, what is wrong with tinning the tank and then just laying a coat of zinc primer over that and call it a day before repraying? Can the tin job be a stand-alone process with no lead work? Or am I not grasping things?