Use of plasma cutters

  1. sparky01 Member

    Posts: 10
    Can somebody explain the basics of using a plasma cutter. I had a quick go, operated the torch air came out. But what next, do i touch the work with the torch or not. Is the air heated at the tip of the torch, and why does the tip not burn away with the ark. I know the tip is called a castle one cos its got grooves in. If i touch the tip on the work it arks, is this ok. Can you tell i haven't used one before. I' thinking of adding a small one to my workshop.:welder:
  2. mr cheese Member

    Posts: 9
  3. mr cheese Member

    Posts: 9
    also mate forgot to say i do have to touch the work with the cutter to get arc started and i continue holding it against as i cut there are also some vids on youtube try either cut 40 or cut 50 in the search bar then checkout H20 cutter not sure exactly what its called but you will know when you find it lol
  4. astro_al Rocket Scientist

    Hi, useful bits of kit!

    There is too much physics involved to go into here, but very basically the hot arc melts the metal and then the air stream blows it away.

    How you operate it depends on the machine, some you just plonk the torch down on the work, press the go button and just run it about like a pencil, others you need to manually maintain a small stand-off distance between torch and work piece. Others have a sprung tip which you need to depress against the workpiece to start the arc - it all depends on age and machine specs.

    Get the biggest one you can afford, most manufacturers over-cook their cut capacity claims - especially the cheaper brands. Oh, and buy a Hypertherm.


    P.S. There is a Plasma Cutting section in this forum for plasma related questions.
  5. paulmowers

    paulmowers Blast boy thas hot

    This is in the plasma forum section, isn't it, or am i lost


    one other point to remember is make sure you have plenty of clean dry air available, if you run short of air you will melt the electrode, I forgot to plug the airline in once on mine, got one massive flash from the tip and half the elctrode had gone:o

  6. astro_al Rocket Scientist

    Yes, but when I wrote that it was in a different section - damn Mods trying to make me look bad!

  7. paulmowers

    paulmowers Blast boy thas hot

    Hi Al

    When i read that I had to look twice to check where i was:laughing:

    They usually put a *moved* notice on a post when its moved, guess they forgot.

    all the best paul
  8. mr cheese Member

    Posts: 9
    AH at least im not the only one thats done it lol
  9. Wozzaaah

    Wozzaaah The wizard of woz Staff Member

    That's only if we permanently redirect posts, an expiring redirect won't show it as moved.

    Apparently, using the pilot arc start without actually arcing onto the workpiece will drastically shorten the life of the tip and electrode too so if the arc doesn't start first time, check the return clamp is properly connected to the workpiece.
    They're great bits of kit, here's a little video of one (same as mine) in action for those who've never seen one.
  10. Bsmith Member

    Posts: 1,102
  11. clevinski Member

    Wait a minute... :confused:

    Plasma cutters require shielding gas AND compressed air??? I'm looking at page 4 of the "How Stuff Works" article above.
  12. Welderpaul

    Welderpaul Moderator Staff Member

    Posts: 10,585
    Compressed air only. Nitrogen can be used in place of compressed air, but in most applications, compressed air is ok.
  13. shenion

    shenion Tool Pack Rat

    Posts: 7,600
    Stone Mountain, GA USA
    Smaller ones use just compressed air. Larger ones used a shielding gas to make a cleaner cut.
  14. clevinski Member

    Ah, thanks for clarifying...
  15. shenion

    shenion Tool Pack Rat

    Posts: 7,600
    Stone Mountain, GA USA
    That video Woz linked to is a compressed air one.

    I have a smaller one (25A.) Real nice to have. You get spoiled by them ;)
  16. clevinski Member

    Scott, what is the maximum thickness you can cut with a 25A?
  17. shenion

    shenion Tool Pack Rat

    Posts: 7,600
    Stone Mountain, GA USA
    25A does 1/8" cleanly. 3/16" if the tip is new with a bit of slag.

    Says 3/8" in the manual max severance.

    I just did a bunch of 1/8". It is a bit slow. I would love to have a 40A as the 25A means you move slow and freehand you see all the jitters more.
  18. sparky01 Member

    Posts: 10
    Using a Plasma Cutter

    I've now bought a Cebora plasma pocket 25. It does ok for what i want,And its in really good condition. Performs very well on 1mm/2.5mm and small enough to carry about. I'm appy.
  19. Wedg1e

    Wedg1e They call me Mr. Bodge-angles

    Posts: 3,501
    Teesside, England
    Just bought an Oerlikon Citocut 10i. 6mm plate, 30A, no problem. 2mm sheet, like a hot knife through butter at 15A. Will still cut it at 10A but a bit spattery. Will happily pierce 3mm mid-sheet, haven't tried anything thicker.
    Also whistles through lead although the cut isn't clean (not yet anyway).
    Struggling a bit with aluminium, anyone know something I don't?
  20. paulmowers

    paulmowers Blast boy thas hot


    have never tried to cut ali, but from what ive heard it takes a lot more power as it disipates the heat so much quicker than steel.

    Cutting lead! I would be very carefull of the fumes from that stuff:o heavy metal poisoning:o

    Cheers Paul..
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