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Cut 25mm steel - no sparks.

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  • #31
    Peter, from the limited info, I am assuming this is a "scrapping" job, and that it involves vertical curved surfaces, the material is "mild steel" and because of the prohibitions, cost and hence time, is not a major problem. While you said that you cant PRODUCE sparks from cutting, you implied that you could use electrical tools. This also can involve more than one worker.
    If these are indeed accurate assuptions, then chain drilling COULD be a winner. IF you, (or someone,) cobbled up a magnetic holder for an 18 volt Li ion drill, (or corded, your choice,) with cobalt 6mm bits, it should be possible to drill about 30 holes per hour, with 1mm or 2mm gaps. (If this is standing, you cant possibly cut continuously to an open face.) If my arithmetic is close, one person can cut about 1.7 meters in a seven-hour day. For four workers, it is a bit less than a two-week job.
    Any MAGIC BULLETS?
    Duffy, Gatineau, Quebec

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    • #32
      Sounds like an interesting place to work. The lower explosive limit of pure ethanol is 3.3% in air. If there is anything near that amount in the atmosphere everybody should be stone drunk. Also, the flash point is 14C. On a nice chilly day the only hazard will be from puddles of liquid on the ground.
      Free software for calculating bolt circles and similar: Click Here

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      • #33
        Originally posted by lakeside53
        Hold on.... Maybe it's made into the "low cost" generic Vodka, Gin, ....
        You mean the kind that comes in Aluminum cans
        I just need one more tool,just one!

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        • #34
          Boots and Coots to your rescue------

          We've hours and hours erosion perforating, also cutting off 24 inch heavy wall casing below the mudline, etc., etc. Rockwell 80 stuff. Takes about 30 minutes max to cut off any oilfield tubular, submerged, and would make a nice fresh water mess inside a refinery, or factory-------

          http://www.halliburton.com/public/bc...ets/H03491.pdf

          --G

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          • #35
            Ok guys here's an update. Sorry it's took so long but I set off at 2am this morning for a 5 hour drive and went stright to work. Can't take any photos either which is a bummer:

            Firtly thanks for all the good ideas and feedback. As soon as I saw the job I was resigned to using the recip saw because they forgot to mention some internal features inside the flue which meant the cut had to be steered up and down/around them. Obviously not possible with a circular blade.

            Oh and it was Ethylene - not Ethanol.

            Duffy has pretty-much dead-nailed the conditions, vertical curved surface and whilst there are some 'intrinsically safe' areas this isn't one of them so electric tools allowed but no showers of sparks etc. They ruled out the cold-cut saw after a trial on the ground.

            Mild steel flue 25mm thick wall, 7 meter circumference and three of us cut around it in about 2.5hrs with a recip saw each which I was very surprised at. 14tpi blades lasted about 100-150mm of cutting if I used the adjustable foot to make use of as much tooth as possible. I also used cutting fluid to try to keep the heat down in the blade and it worked quite well.

            Got another to do tomorrow then a long drive home. Once again thanks a lot - this is what makes HSM such a great place!
            Peter - novice home machinist, modern motorcycle enthusiast.

            Denford Viceroy 280 Synchro (11 x 24)
            Herbert 0V adapted to R8 by 'Sir John'.
            Monarch 10EE 1942

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            • #36
              Uh.., just out of curiosity, would a diamond coated wire saw (in steel) be an absolutely, for sure non-sparking process?

              That sounds to me much like the flint/steel fire starting process. (??)

              I've seen TV segments showing that process in cutting marble and stone, where it's running in a wet slurry. But with steel I'd think sparks would certainly be possible, or even probable.
              Lynn (Huntsville, AL)

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              • #37
                Curious, what "support" has the part removed got?

                Maybe complete out to lunch here, but I just envision a crane putting slight tension on some sort of sling set-up which then lifts once the cut is complete?

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                • #38
                  Originally posted by lynnl
                  Uh.., just out of curiosity, would a diamond coated wire saw (in steel) be an absolutely, for sure non-sparking process?

                  That sounds to me much like the flint/steel fire starting process. (??)

                  I've seen TV segments showing that process in cutting marble and stone, where it's running in a wet slurry. But with steel I'd think sparks would certainly be possible, or even probable.
                  You do get sparks with a wire saw run either wet or dry when cutting bare steel. The biggest difficulty with cutting large diameter tube is that the wire cuts one side so when you are part-way through the cut you are pulling the wire through a very acute angle on the entry-turn - as sharp as 45 degrees - and this tends to strip the diamonds off the leading edge of the bead. Towards the end of the cut it is very prone to jamming too as the steel bends and if the holding load on the crane is too much less than the actual load it wrinkles the tube at the cut and the wire is permanently stuck

                  RussZHC: Yes the piece being cut is held by a large mobile crane - a thousand-tonner actually.
                  Peter - novice home machinist, modern motorcycle enthusiast.

                  Denford Viceroy 280 Synchro (11 x 24)
                  Herbert 0V adapted to R8 by 'Sir John'.
                  Monarch 10EE 1942

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