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  1. #1
    Join Date
    Jan 2004
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    Mackay North Qld
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    4,419

    Default Who has an oxy cutting torch ?

    Who has an oxy cutting torch ?

    Next hard question is "Who can use it their oxy torch properly?".

    Any takers for a run through for the basics on gas axemanship ?

    Or would a write up on gmaw be preferred -thats MIG if you did not know.

    I thought it might busy up the board a little bit.It's getting a bit sleepy around here.

    Comment please !

    Grahame

  2. #2
    Join Date
    May 2005
    Location
    Cockatoo Vic
    Posts
    77

    Default

    Going by your exellent series on stick welding I think that would be a great idea.

    Not so much for me (I am a boilermaker) but many would find something like that very informative.

    So I reckon go your hardest

    Greolt

  3. #3
    Join Date
    Mar 2005
    Location
    Too close to Sydney
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    0

    Default

    Quote Originally Posted by Grahame Collins
    Comment please !

    Grahame
    I've got one and have cut with it but to be honest, beginner would be too nice for my oxy cutting skills. I did some research and saw the pictures of the lovely cuts but I'll be stuffed if I can get that to happen over more than 50mm. And they are never straight.

    That said my mig welding is good. I found preparation to be the key.

    Seriously interested in hearing from a pro, so go for it mate.

  4. #4
    Join Date
    Oct 2004
    Location
    Melbourne, Australia.
    Posts
    32

    Default

    I have an oxy cuting kit, in fact I have a complete Comet 3 kit I purchased second hand 23 years ago. It was bought off a tradie who had to replace it on a building site as it had the Mickey Mouse gauges, the site required the new vertical gauge for him to stay on site.

    I have cut a few things and have to say that when cutting a Ĺ" plate of steel for a bench top I was making (and still have) I learnt on the job so to speak. I did last year, watch a tradesman doing a cut on Ĺ" sheet steel and thought of how neat and precise the cut was made.

    At times I have made spectacular cuts, but the next one wasn't that crash hot, so I'm obviously lacking on just what it is I need to do.

    Any lessons you can offer would be received gratefully.

    Mick.

  5. #5
    Join Date
    Aug 2002
    Location
    Melbourne, Victoria
    Posts
    559

    Default

    Plasma cutting Mmmmmmmmmmm
    "Clear, Ease Springs"
    www.Stu's Shed.com


  6. #6
    Join Date
    May 2005
    Location
    Newcastle
    Age
    67
    Posts
    864

    Default

    I have a gas axe have used one for 90% of my at sea life, still but rearly use it these days but still keep a full gas set at home. Have cut most stuff even stainless, though wet electrodes do a better job , Hardened container mounts , most thickness steel from 1/8th to 6" bar .


    For basic cutting close all valves on the gun, open valve on gun and set pressure at bottle for acetylene at about 90-100 kpa close valve on gun. open rear oxy valve almost fully depress cutter trigger and set oxy pressure at bottle 300-400 kpa at bottle leave rear valve open
    Open acetylene and light , open front oxy and adjust till just blue flame , no yellow and flame touches the tip , depress lever ( trigger) ensure flame does not go out or lift away from tip , adjust rear valve to suit and if necessary front valve.

    Hold flame on edge of job and wait till small sparks jump from heated surface , as this usually indicates that the material is hot enough to cut , depress lever , main flame just above surface and bring down to touch and start cutting in a slow fluid motion , ensure you are cutting the materrial , speed of cut comes with practise the thicker the material the slower the cut


    Always have enough oxy to blow slag away without cooling the job too much
    Increase pressure for very thick work
    Keep all the holes on your tip clean of slag etc
    Use right size tip for material your cutting



    All the rest is practise or being taught hands on


    And always turn gas off at bottles and release pressure from lines
    Buy fit and use anti flash back arrestors at the gun
    Check , inspect hoses and o'rings regularly Leaking perferated hoses will kill you , and can be replaced for bugger all.
    Don't fit new fittings to hoses unless you are trained and have the correct tools
    Never use grease oil on fittings or threads
    Store bottles in free air space , been a few vechicles blown up by leaking bottles left overnight



    When you burn yourself , and you will , cool the burnt area in ice etc for at least 20 minutes as the sub surface fats in your skin will still boil





    Hope this helps
    Russell






    Useless infomation for the day

    Man who run behind car get exhausted.

  7. #7
    Join Date
    Sep 2004
    Location
    Glenhaven, NSW
    Age
    76
    Posts
    205

    Default

    I've had a CIG colt22 oxy set for 30 years and use the cutter very rarely as it uses loads of oxy and with my poor technique, the cuts take more time to clean up than cutting with a friction disc. I use the oxy cutter for really heavy stuff that doesn't need to look pretty. Any tips would be appreciated.
    Cheers,
    Graeme

  8. #8
    Join Date
    May 2003
    Location
    Melbourne, Victoria
    Age
    43
    Posts
    150

    Default

    The best tip I can give - you need to get a set of tip cleaners and use them. Nothing stuffs a cut like a dirty tip.

    Next best tip. Always acetylene first. Open it first, shut it off first.

    Dan
    Is there anything easier done than said?
    - Stacky. The bottom pub, Cobram.

  9. #9
    Join Date
    Aug 2005
    Location
    Western Qld
    Posts
    1

    Thumbs up Gas Axe

    Be a good idea for a topic. Very useful to some I think.
    Still use the oxy for Silver and Brass soldering, not so much for cutting anymore, although when we were making points
    (before customers could buy them less retail) the oxy and forge were indespensible.
    The Plasma we now have use at work and on "foriegners" will handle up to 75mm so why reinvent the wheel on that one.
    Always been a firm believer in learn everything about a tool even if you don't use it for that purpose.

    Mulga

  10. #10
    Join Date
    Jan 2004
    Location
    Mackay North Qld
    Posts
    4,419

    Post Oxy Acetylene cutting Pt 1

    Ashore has done a fine job with the basics of Oxy cutting. I can add a few things that I have observed over the years of teaching students.

    Safety

    Never take the oxy plant for granted. Even the smallest set of CYLINDERS mistreated have the potential to kill should things go wrong. Thermally,acetylene is the most efficient gas known to man. It has the greatest explosive range as well.
    It ranges between 3 % acetylene to 97 air mix and 92 % acetylene to 8% air mix.

    If you want experience how a diesel engine combustion sequence works, just leave a trace of oil or grease on the regulator thread where it screws into the cylinder. The bad news is that after the 2000 Lbs. cylinder pressure hits the grease or oil, an explosion usually follows. On the large cylinders it means the regulator explodes at just about face level.

    Setting up
    .Always make sure fittings are the correct ones for the plant. If you are a scrooge donít skimp here. I would caution people not to mix differening brands of OXY gear particularly the Comet 3 clones. The tolerances differ and you put yourself at risk. In my humble opinion the CIG Comet 3 rates with the best the world has to offer.

    New operators tend to set the torch flame too high. At the neutral flame setting if you have to raise you voice to be heard clearly over the noise of the flame its set too high.

    You do not need trainer wheels for any cut under 300mm long. If you are really hard up to cut a straight line setup an angle section with a handle . 50mm equal angle is ok.Cut 8mm from the top to give a vertical height of 42 mm. If I remember it measures 42 from plate surface to the shoulder formed by the nut against the cutting nozzle. This is for a type 41 cutting nozzle only . You might have to check this measurement as after 20 years my memory is a bit hazy.

    Thatís enough for starters I will have to finish this latter.

    Grahame

  11. #11
    Join Date
    Jan 2004
    Location
    Mackay North Qld
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    4,419

    Default Lighting your torch

    Before lighting your cutting torch for the first time in a session you are wise to check a few things first. Over the years I have got into a habit of doing a quick visual check over the connections followed by running my hands almost folded in a loose fist dragged over hoses and connections to check physically for gas leaks.

    I always check my cutting nozzle for cleanliness and if not satisfied clean it with the correct diameter cleaning wire.
    The tip here is to start with one obviously too large and use the one that fits as you work your way down. Incorrect undersize cleaning wires do damage to cutting nozzles by elongating the hole opening and destroying the shape of the jet of gas emitted. Dirty or damaged nozzles will not cut well.

    A word here about nozzle sizes. Cutting Nozzle jet holes are measured in millimetres and parts thereof. Designated sizes of 6, 8, 12 and 15 translate to .6mm, .8mm 1.2mm and 1.5mm. -.6mm will cut down to 3mm and 1.5mm will cut to 75mm thick steel.

    Steel is heated to an ignition point by the preheater flame and a jet of pure oxygen is directed at the preheated point. The result is that the steel ignites or burns.

    My comments here apply to a Comet 3 cutting head but most others are similar. Open the torch primary oxygen valve all of the way. This is the one closest to the hose. It supplies both the cutting stream oxygen and that for the pre heat flame.
    Open the acetylene valve about a third of a full turn and light the flame.

    The acetylene flame should be adjusted until the oily smoke dissipates and the flame becomes very bright. It should lift slightly off the nozzle opening. At this time gently open the oxygen pre heater valve closest to the nozzle. Your flame will form the neutral shape which is a number of cones which do the preheating.

    Adjustment of the preheater valve so that the cones form a soft rounded shape at the nozzle, will produce the ideal neutral setting required for cutting. The nozzle is held with a millimetre or two of gap under the flame tips. Heat the plate edge until it becomes an orange colour and fully depress the lever. A correct cutting speed will result in a stream of slag inclining in the direction of the cut accompanied by a tearing, ripping noise occurring on plates 10mm and up.

    To be continued

    Grahame

  12. #12
    BobL is online now Member: Blue and white apron brigade
    Join Date
    Feb 2006
    Location
    Perth
    Posts
    4,187

    Default

    Last time I used an oxy to cut steel was back in high school maybe 40 years ago?

    Last week I used an oxy to cut the hook out for this tool but my efforts at cutting were . . . let's call them . . . "slow and erratic"!. Yesterday I did a search on the forum here and found up this thread and WHALA! - this evening I applied the refreshed knowledge and . . . . . hot knife through butter time what a satisfying spray of hot metal and sparks - nearly as good as chainsaw milling!

    Thanks Graeme and Ashore
    Cheers

  13. #13
    Join Date
    Jun 2006
    Location
    Vic
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    Default

    Funny that you should bring this up Bob, yesterday and today I have been cutting secondhand steel for the newly acquired hopper for the mill and also had to put some 25mm holes in the base plates which are 20mm thick for the columns and one off the boys said to me "how do you get such a neat hole with no slag and no gunk" and I replied "clean tip, correct adjustment and lots of practice" with a grin on my face.

    Good to know that I can still wield a gas axe with good precision .

  14. #14
    Join Date
    Dec 2005
    Location
    South Australia
    Posts
    668

    Default

    Optimark , interesting point about the vertical gauges 5 years ago I was told by CIG the I had to replace my vertical gauges with the micky mouse type as they could not handle the presure in the latest cylinders

  15. #15
    Join Date
    Aug 2004
    Location
    Lost in Space
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    331

    Default Transforming the Woodrat into a semi automatic oxy cutter!

    Gidday

    I got to admit one of my fav metal working processes at the moment is OXY! I love the dam thing and am in awe of those able to wield a flame blade effectively! I particularly love flame gouging!

    Love setting up a piece of mild steel stock and cutting it with a beautiful smooth finish on the 'quickie' (Our automatic OXY setup at trade school!) I can cut competently by hand but am far from being able to get that smooth finish at right angles that I'd love to be able to achieve consistently!

    Anywaz for those of you that are familiar with the Woodrat Joinery system the creators of this gem have created a hand operated aluminum extrusion that enables x-y axis movement (from right to left or left to right) n I reckon I could fabricate a gem of a semi automatic oxy cutting rig using the rat as a basis...................... Will start posting a few PICS once I start toying with ideas!

    REgards Lou
    Just Do The Best You Can With What You HAve At The Time

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