Bit of help please!

  1. mick w Member

    Messages:
    2
    Southampton
    Knew I'd find a site like this eventually, but it took a bit of searching...
    Many years a go I did a lot of gas welding, but never arc or mig.
    Always fancied a mig welder & I now have an excuse - a 4x4 that needs a few mods, so i've just bought a Cosmo gas/gasless - can't remember the model number - 170 I think, & I paid just under 200 quid for it.
    I have a pile of scrap metal to practice on but the manual that came with it is useless.
    I am confused with wire types/gas to use. I shall be welding mild steel. In the shop there were gas bottles for stainless & alloy, but none shown for steel. There was wire for steel (copper coloured), & gasless wire with a core(silver). So which do I use? Which is easier?
    Apologies for my ignorance....& thanks for a useful site!
    m
     
  2. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    Hi Mick, welcome to the forum.

    I'll have to be quick - working tonight. You can weld mild steel using CO2 gas as a shield. Pubs use it to pump beer, although that source has dried up with the bottle safety regulations.

    The best stuff to use for mild steel is Argoshield which is mostly Argon, but has a little CO2, and also about 2% oxygen. I use Argoshield Light.

    It's easier to weld with plain wire (rather than shielded) together with shielding gas. The copper coloured stuff sounds right. 0.8mm would probably be the best thickness, although you'll need to make sure tou have a 0.8mm nozzle for the end of the welding torch.

    I find shielded wire a pain - there is too much smoke from it, so I'd always go for plain wire and gas.
     
  3. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    Hi, It's the weekend now, I can breathe a little. Busy week!

    There are a few advantages of Argoshield over CO2. These are:
    Lower fumes, less splatter, smoother arc, and a neater weld.

    The disadvantages of Argoshield are the gas conducts heat better so you have reduced penetration, and it's more expensive.

    I did a little research into Argoshield. Apparantly, Argoshield light is good for steel up to 4mm. You can also buy Argoshield universal for 4mm to 10mm, and Argoshield heavy for over 10mm. See http://www.bocindustrial.co.uk/product_information/product_data_sheets/argoshield.asp for the specifications. The differences seem to be C02 content wigh increase with metal thickness.
     
  4. AndyT Member

    Messages:
    4
    Kent UK
    Thanks for the info re gas. I have been using CO2 and while it works ok, if a little spattery (is that a word?), it doesn't produce as neat a weld as the argon/CO2 mix. I will be onto BOC next week. I gather that their size X cylinder of Argoshield Light is equivalent to 240 of the DIY store size bottles. Bottle rental is £42 p.a. and and the gas is £37 plus £38 for a regulator and adaptor (figures from BOC)

    I had another go today and the results are shown here:

    http://www.andytaylormusic.com/midisk/Welding pix/23:04:05/

    Its the first time I have managed good penetration (!) on the first bead of the day. The bead in 'first go' is a little wayward while the 'getting there' is neater with a slight waffle in the middle where my glove refused to slide on the bench!. You can see at the R.H. end of the bead is where the gas ran out! (I'm left handed) and the 'No Gas' bead speaks for itself!
    ( 1.5 mm mild steel- kindly donated by a local fabricator-, .6 wire, Argon/CO2 - Clarke's own brew. the volts were on 2/low and feed speed 6 for first go and 5+ thereafter).

    and so a wire question..
    My machine (Clarke 100EN) works fine with .6 wire and .9 flux cored wire using the appropriate drive roller grooves but it doesn't seem to like .8 wire producing spitting and all kind of fireworks at most settings. i think it is slipping but no amount of pressure seems to affect this. The wire reels are all .7Kg size. On going back to .6 all returns to normal. A slight improvement was made by using the tip as used for flux cored (presumably .9 or 1.0 mm) but only at high voltage and wire speed settings. Any ideas?
    Malcolm, you mentioned an adjustment you made to your machine's feed. could you go into more detail please?

    cheers

    Andy
     
  5. malcolm

    malcolm & Clementine the Cat

    Messages:
    9,134
    Location:
    Bedford UK
    Blimey - 240 bottles? I get through a big bottle of gas faster than once a year. Those little bottles cost £10 each so I'd be spending £2500 a year! I would have to get a proper job to fund that :D

    My modification to the wire feed was to bend the top roller over so the two rollers were parallel. Mine had become bent over time and had stopped gripping the wire.

    Your welding looks OK - the penetration is there. Were the no gas photos with gasless wire. THey really have oxidised. You might try turning the amps down a step and doing a wider circular motion and a slower weld. That way you'll get the cool weld bead look.

    I enjoyed the rest of your site - you've been doing some cool things.
     
  6. AndyT Member

    Messages:
    4
    Kent UK
    Thanks for your comments Malcolm. I'll give the circular stuff a try next. The no gas pix were simply no gas and ordinary wire. I hadn't realised the gas had run out at the end of the 'getting there' bead (you can see the oxidation) and tried another weld resulting in the mess as shown! When I get round to a proper gas bottle I will post some more pix of the newbie's progress!
    Incidentally I would add a baseball cap worn backwards to your safety clothing. I didn't bother with it for just one weld, and you guessed it, I got a spark on the bonce.... ouch!
     
  7. geetee Member

    Messages:
    32
    Edinburgh
    :lol: :lol: :lol:
    yes, been there.
    not so good when you have no hair i can tell you!!! :roll:
     
  8. woolstar Member

    Messages:
    1
    flagstaff
    We don't use much tri-mix out here, but we do use a lot of argon/co2. Usually we're using 25% co2 which is called C25. I have a bottle of co2 & argon (for TIG) at home, so I'm looking for a gas mixer to be able to make my own.

    Two other benefits of C25 besides splatter is lower heat and spray transfer. Straight CO2 will disassociate into O2 & CO and then re-combine in the weld, running hotter. Also Argon (being a heavier element) absorbs more heat per molecule. That's why they used to use Helium for TIG (it was originally called Heliarc), and they still use Helium when penetration is important (like on Titanium).

    Spray transfer is the prettiest weld you ever saw, but it requires a mix. You can't do it with straight CO2. Usually its done with the big machines, but I found I could spray transfer with 0.6mm wire and C25 on a little Miller 135.

    Anyways, if you're doing thin stuff or want to play with spray transfer, I recommend C25 and the thinnest wire you can get (like 0.6).
     
  9. flashburned Member

    Messages:
    2
    usa mi
    try tuning the wire to the power setting this will give you a much better weld. to do this while welding on some scrap medal turn the wire speed up or down till you get a steady sound no poping or cracking just a steady buzz like bacon frying
     
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