oxy-acetylene cutting heavily rusted plate steel

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Hello,I am planning a project to cut a mural into an old (from the 1920's) sheet of plate steel connecting two bridge pylons. It isn't structural, and measures 4' tall x 10' wide x 3/8" thick. The steel is a vertical plate, and is heavily pock-marked (looks like the surface of choppy water), but doesn't have significant rust flaking off, as opposed to the horizontal surfaces which are coated thick with flaky shale-like rust deposits. The plate varies in thickness from 1/8" to 3/8" due to the pock-markingThe thing is, I must take the cutting torch on a sled over snow, one mile by foot to the old pylon in mid-winter to access the site via an ice bridge. I would hate to goto the trouble to get there and have terrible results trying to hack through old rusty steel. Any suggestions, thoughts or previous experience?Thanks
Reply:Anything on a bridge IS structural.Is this bridge still to be used? As far as the cutting, Rust won't affect it much.Esab Migmaster 250Lincoln SA 200Lincoln Ranger 8Smith Oxy Fuel setupEverlast PowerPlasma 80Everlast Power iMIG 160Everlast Power iMIG 205 Everlast Power iMIG 140EEverlast PowerARC 300Everlast PowerARC 140STEverlast PowerTIG 255EXT
Reply:I'm going to agree with Lugweld on the structural part and disagree with him about the rust. A little rust isn't a problem but heavy rust needs to be removed, on both sides of the plate. Heavy rust deflects your preheat and oxygen on the cut side and heavy rust on the back prevents the slag from blowing off cleanly. You can't cut rust, it's already iron oxide and you can only try to blow it out of the way. Cutting is like welding, the cleaner the metal the higher the quality of work.
Reply:Originally Posted by OldtimerI'm going to agree with Lugweld on the structural part and disagree with him about the rust. A little rust isn't a problem but heavy rust needs to be removed, on both sides of the plate. Heavy rust deflects your preheat and oxygen on the cut side and heavy rust on the back prevents the slag from blowing off cleanly. You can't cut rust, it's already iron oxide and you can only try to blow it out of the way. Cutting is like welding, the cleaner the metal the higher the quality of work.
Reply:if you have been approved and have all the right permission i way go for it.    i wouldn't worry about metal being lightly rusted, you just don't want heavy rust.  take a good scraper and a stiff wire brush.  from the sound of the distance i would use a four wheeler or a snow machine to pull you back there and take a small genset and a grinder with a cup brush on it.  also from the sound of the project you will want to make you lines that will last more than a day.  i would use silverstreak instead of the standard soapstone.  silverstreak won't whip off or wash off as easily as soap can.oh, take pictures i bet this will be a looker.
Reply:Originally Posted by BlandI am planning a project to cut a mural into an old (from the 1920's) sheet of plate steel connecting two bridge pylons....  ...I would hate to goto the trouble to get there and have terrible results trying to hack through old rusty steel. Any suggestions, thoughts or previous experience?