Some mig welding questions

  1. DennisCA

    DennisCA Member

    Messages:
    1,248
    Location:
    Finland
    I'm going to look at a welder today (Kemppi Kempomat 2500) and if I bring it back I will have my first mig welder.

    I have a few beginner questions...

    1. How important is the mig torch? It has a euro connector and some unknown brand mig torch I might be able to determine what torch it is when I can inspect it myself. But it's not a Kemppi original. I will likely use the existing torch for a good long while yet but I am curious anyway. Kemppi torches seem to be about 1.5 - 2x the cost of Binzel torches from what I can see. Are they worth the extra money? Are there any particular issues one should consider when looking at torches?

    2. How big a spool should one get? The welder can take a 15kg spool, but I have some vauge memory of having read that if you are a hobby welder and don't use that much mig wire, then it can get rusty with time, so it was better to buy 5kg spools that would be used up faster. Anyone care to chime in on that?

    3. I have no MAG gas, not even pure co2. This purchase will clean me out a bit so I can't be buying a proper gas bottle for a while. I was wondering if I should buy a spool of gasless mig wire so I can at least use the machine, or try and run with pure CO2, I think I could scrounge up some smaller CO2 bottles for a lot less money.

    Any other things to consider?
     
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  2. Munkul

    Munkul Jack of some trades, Master of none

    Messages:
    3,157
    Location:
    Cumbria
    1. the MIG torch is extremely important - if the liner or gun or tip, or any part of the torch is worn out/damaged, then you'll get horrible welds. Having said that, most popular brands of MIG gun work fine, provided they aren't worn out. First thing to do is to pull the liner out at the euro fitting end, and blow it out with compressed air, and inspect for faults. Second thing to do is to check the gun neck, gas shroud, tip holder and contact tip for wear/damage. They can look hot and burnt, but as long as the wire contact is good and gas is getting through, it will weld perfect. Make sure you fit a brand new tip anyways.
    Several machines that came through my hands - I just fitted a brand new Binzel torch as a matter of course, without trying to repair the old one. It makes getting tips and spares much easier anyways.
    If you buy a new torch, an MB25 is a good size to start with, if you're mostly working with material under 6mm.

    2. good quality wire rusts a lot less than cheap stuff. But if you're really not going to use it much, then just get 5kg to start with. Try to get Esab or Bohler or Elga, but not sure if they sell many smaller reels. Even cheap A18 wire will usually work fine though, just don't let it go rusty.

    3. You'll have a much better time if you can just wait and save up for a proper cylinder of argoshield light, pure CO2 is spattery. Do they not do rent-free hobby size cylinders in Finland?
    You could try some gasless wire, but I fear you'll have a bad time of it.

    I hope the Kempomat is as good as it should be :) they're very simple machines, but really quality - it should have a really positive arc start and super smooth arc. Both things that a damaged or worn torch will affect.

    Oh, and don't forget a good return clamp! Something with lots of copper in and a strong spring, or made from brass.
     
  3. DennisCA

    DennisCA Member

    Messages:
    1,248
    Location:
    Finland
    Regarding point 3 they do, but I don't have that kind of money to spare after this purchase. The plan is definitely to get a proper bottle of argon mix gas later, but it's a shame ot get the new welder and not use it for a couple of months so I was considering temporary arrangements so I could test it out.

    I have pure argon bottle for TIG but I don't think that is of any use to me here.
     
  4. optima21 Forum Supporter

    Messages:
    3,087
    Location:
    halifax, England
    you'll be fine with 5kg rolls as a hobby welder, even that may last a year (or two depending on how much you weld). When I changed from CO2 to argoshield light, although it was less splattery, it wasnt by much (might be that co2 wasn't too splattery for me) so for home use may not be so bad.

    yeah and pure argon doesnt work with mig, I tried it when I ran out of the correct gas, and the bead is awful and didnt penetrate properly
     
  5. Country Joe

    Country Joe Argoshield Dark

    Messages:
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    Somerset - United Kingdom
    You'll be able to weld Aluminium with a pure argon shield.

    All the Best,
    CJ
     
  6. DennisCA

    DennisCA Member

    Messages:
    1,248
    Location:
    Finland
    Now it's home:

    [​IMG]

    [​IMG]

    The tape says service cleaning and various dates.
    [​IMG]

    Seller says it came from a local company that went out of business. Tested it and everything seems to work, got an almost new 15kg spool of wire with it, lincoln I think.
     
  7. Country Joe

    Country Joe Argoshield Dark

    Messages:
    1,673
    Location:
    Somerset - United Kingdom
    Looks good - I always quite liked those Kemppi sloped control panel.

    All the Best,
    CJ
     
  8. metalmelt Member

    Messages:
    595
    Location:
    UK
    One point Munkul missed was a braided bridge in the earth clamp which bridges between both sides of the clamp to stop the hinge pin and spring conducting between sides.
     
  9. northwest

    northwest Member

    Messages:
    2,073
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    Manchester UK
    The torch on that machine is a Binzel Evo, very good torches. As Munkul says, check the liner, tip and shroud and you should be good to go.
     
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  10. davidjohnperry a different breed

    Messages:
    2,253
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    yate/bristol
    Those machines are amazing I've got three 3 phase versions they are amazing machines
     
    metalmelt likes this.
  11. TechnicAl

    TechnicAl Member

    Messages:
    8,256
    Location:
    Rotherham
    I had one of the first Kemppi 240v MIG sets (a prototype)...Mr Kemppi himself, Matte, gave it to me to try before we started to sell them.....way back when....We were doing the Great Norfolk Show and we knew that Farmers would love a 240V machine so we took all we could get and sold them all in no time....I think they were about £100 but that was about 1978...
    I had it in my garage for years and never used it so I gave it away to a friend.
     
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  12. davidjohnperry a different breed

    Messages:
    2,253
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    @TechnicAl that is such a cool story you should right a book about the history and knowledge you've experienced would be such an amazing read
     
  13. DennisCA

    DennisCA Member

    Messages:
    1,248
    Location:
    Finland
    I am curious what did model numbers did those old kemppi welders have? I'm quite sad there is no comprehensive history of Kemppi and their models and developments through the years.
     
    Munkul likes this.
  14. TechnicAl

    TechnicAl Member

    Messages:
    8,256
    Location:
    Rotherham
    I cant remember.
    I might have some old literature...Ive got boxes full of stuff...next time Im in the mood I will have a look
     
  15. metalmelt Member

    Messages:
    595
    Location:
    UK
    Hold on a minute, if Al did that it would be a series of volumes as long as War and Peace each volume.
     
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  16. DennisCA

    DennisCA Member

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    1,248
    Location:
    Finland
    I've read books that were longer, no problem for me.
     
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  17. metalmelt Member

    Messages:
    595
    Location:
    UK
    All 26 volumes of Encyclopedia Britannica???
     
  18. northwest

    northwest Member

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    Location:
    Manchester UK
    I am trying to read the Internet and I am making good progress. I good deal easier if you ignore great chunks of it (facebook, tritter etc.)
     
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  19. DennisCA

    DennisCA Member

    Messages:
    1,248
    Location:
    Finland
    Mostly novels, the Stormlight archive books (4 books so far) are between 1100-1330 pages long each.
     
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  20. davidjohnperry a different breed

    Messages:
    2,253
    Location:
    yate/bristol
    First it would look cool on the shelf
    Second instead of me having to ask al a question I could just grab book 4 index ah 309 disimalar rod made in Sheffield by indexme coating rainbow unicorn tears and the second tree of the third tree coating will weld all all your Hope's and dreams. I dont know al personally but the man has some serious knowledge and experience some in which all never see in a life time. Maybe a podcast since it's the digital age
     
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