Carbon Arc

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Using my old lincoln 225 engine drive to carbon arc with 5/32 arcair carbons. I know the machine is right on the limit but I don't do much of this. Sometimes it cuts a nice clean gouge, but on other passes it seems to just swirl the metal and fuse back in without cutting a gouge. This is especially prominent when going for a second pass in a gouge. What should the machine be set for DC, electrode + OR -, Tried various air settings from 65 to 110 PSI , I thought I might be geeting to much cooling from the air jet so I turned it down but it didn't seem to matter."Si Vis Pacem Para Bellum"Lincoln Idealarc 250 AC/DCMillermatic 251   Syncrowave 300   30A spoolgunLincoln MP210Hypertherm 45(2) LN 25(2) Lincoln Weldanpower 225 CV(4) SA200   1 short hood    SA250    SAM 400
Reply:what polarity and amperage are you running? Also sometimes when using smaller rods they don't always lay straight in the torch and this will cause the angle of the air to change and not blow on the area you are trying to cut.
Reply:Use 1/4 or smaller carbons.  it will be easier to do and easier on your machine.  You should have at least a constant supply of air at over 80 psi.  You push the rod rather than drag.... make sure your orfices are under the electrode rather than on the upper side.  The slag should fly outward and forward as you push the rod.
Reply:Don't go any faster than you have to. push it away with at least a15 degree angle ,so that it blows away metal and all ,leaving a nice clean "trench". Move it STEADY , not "blap, blap, blap. "It should sound like a loud "Shhhh".With practice,and steady nerves, you might be surprised how clean a gouge you can make. Good enough to weld in ,with NO other prep. But, that will take a lot of practice, to get that good. If you get a chance, try arcing with a bigger machine , (none are "too big") and a bigger carbon. And try to not flash yourself. I have accidentally flashed myself with 1200 amps and a 5/8" carbon, only saw stars for a few minutes, but  luckily no damage.[SIZE="5"Yardbird"
Reply:If you try 1/8" carbons, you will have better luck.  I have a lincoln 200 amp gas welder and anything bigger doesn't always get a nice clean cut.  Not enough amps for 5/32 or 3/16 rods.  I do enough gouging that I bought a bigger welder.  Now I can run 3/16 at 220 amps and gouge all day.  1/4" is a little too big for my 250 amp welder.DavidReal world weldin.  When I grow up I want to be a tig weldor.