Plasma cutting along a drawn line?

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I realize that this isn't technically a welding question, but I couldn't find the perfect forum board, so here goes...Has anyone ever hand cut along a drawn line using a plasma cutter? ...and, if you have, what did you use to draw the lines with?  I've never used a plasma cutter before, but I understand that the light emitted during the cutting process is super bright; hence, my question.I believe that banking institutions are more dangerous to our liberties than standing armies. - Thomas Jefferson
Reply:

Originally Posted by HandLogger

I realize that this isn't technically a welding question, but I couldn't find the perfect forum board, so here goes...Has anyone ever hand cut along a drawn line using a plasma cutter? ...and, if you have, what did you use to draw the lines with?  I've never used a plasma cutter before, but I understand that the light emitted during the cutting process is super bright; hence, my question.
Reply:I agree about using a guide when making long straight cuts, but sometimes, such as when cutting curves, a guide would be hard to make or to use. If one knows the system/torch and doesn't have to vary speed or stand-off distance to keep from loosing the cut, once started, the jet doesn't need to be watched. Keep the head behind the torch so the side of the tip follows the line, allowing for how much off-center the side is if not going straight left or right. Reflected/refracted light will generally be enough to see a well-scribed or a white (or aluminum) marker line on the workpiece. If the metal is too shinny, first coat it with Dykem. I can't remember when I haven't used my old shade 5 gas welding goggles when plasma cutting, although I must have used a hood a time or two when I wanted to use reading glasses for better vision.Another important point: don't ever get old and shaky; the plasma torch accentuates such movement..Last edited by Oldiron2; 5 Days Ago at 01:42 AM.
Reply:I do most cuts by hand, its almost instinct after torch for so long. Sometimes I hide the arc, usually use safety glasses, dark is fine.  The light is bright but the current is low and l do watch it if I am trying to be really accurate.  Also do use some guides, mostly paint stick of yardsticks and cut holes with saw in some luan for rounds.

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Last edited by Sberry; 4 Days Ago at 07:55 AM.www.urkafarms.com
Reply:I like to use Silver Streaks or Silver Pencils. They light up very well from the plasma arc or torch flame.Thermal Arc 320SP ( Lorch )Cobra PythonsThermal Arc 300 AC/DC  ( Sanrex )ESAB 301i AC/DC  ( Lorch )Thermal Arc 161STL  ( WTL )Thermal Arc 190S  ( Sanrex )Cut Master 82, 42. Cut45 ( WTL )Victor Gas Apps.Boxes and boxes of welding crap.
Reply:

Originally Posted by Rondo

I like to use Silver Streaks or Silver Pencils. They light up very well from the plasma arc or torch flame.
Reply:Depending of cut amps, shade 3 can be used also.. It can help with seeing the line on sheet metal. Drag tips also play a roll in keeping the arc below the plate..I normally wear #5 for standoff cutting, or CNC cutting.Esab/Lorch ET-220iEsab 160i caddyEsab CV353Thermal LM-200/ Lincoln feedersThermal 60i- 3phase Pak 50Thermal 35CThermal 15cINE 1500 Klutch 220iBlue Demon/140 msi/90sti
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Originally Posted by 52 Ford

Paint markers and Sharpies. For most cuts, you're going to be a lot better off using a guide. Figure out how far to offset your guide. Make sure you wear some shade 5 or darker goggles. https://www.lincolnelectric.com/en/products/k4708-1 mine are similar to these. You might want a darker shade, though.Sent from my Lincoln Buzzbox using Tapatalk
Reply:as others have said using a straight edge as a guide  (if possible)  would be my first choice …

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Reply:I agree with those who have said use a guide,,,, B U T,, When you absolutely have to free-hand cut,, there is a simple rule to follow that improves cut quality 400%Only cut left to right, (or right to left) as that is the most accurate way that you can move your hands.Do NOT cut towards you, or away from you.If you cut side to side (left to right,, etc) it is easy to practice the cut with the torch off, simply moving the torch to see if you have the range of motion needed.Practicing towards, or away from you is almost impossible.I had been taught this at US Navy Shipfitter "A" School (now called Hull Maintenance Technician "A" School) .Some years later, I attended a trade show, and a welding supply had a guy demonstrating the "magic" that could be done with a cutting torch.Well, I noticed that he would reposition his body for EVERY cut, to make sure that the cut would proceed, side to side.
Reply:

Originally Posted by SweetMK

I agree with those who have said use a guide,,,, B U T,, When you absolutely have to free-hand cut,, there is a simple rule to follow that improves cut quality 400%Only cut left to right, (or right to left) as that is the most accurate way that you can move your hands.Do NOT cut towards you, or away from you.If you cut side to side (left to right,, etc) it is easy to practice the cut with the torch off, simply moving the torch to see if you have the range of motion needed.Practicing towards, or away from you is almost impossible.I had been taught this at US Navy Shipfitter "A" School (now called Hull Maintenance Technician "A" School) .Some years later, I attended a trade show, and a welding supply had a guy demonstrating the "magic" that could be done with a cutting torch.Well, I noticed that he would reposition his body for EVERY cut, to make sure that the cut would proceed, side to side.
Reply:And a “little” off topic but important none the less ….

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Reply:

Originally Posted by SweetMK

Only cut left to right, (or right to left)[/B] as that is the most accurate way that you can move your hands.Do NOT cut towards you, or away from you.
Reply:Here are a couple pics to help show how the plasma height, torch angle, and speed affect cut quality.The last pic shows how cut direction affects quality on curves, circles, or whatever.




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Reply:A very kind friend of mine loaned me a nearly-new Hypertherm 45xp to try out, so I took all of the advice I received in this thread and put it to the test: several times.   The 45xp struggled to cut 1/4" mild (with way too much dross), much less the 1/2" stuff I've seen cut in YT videos.  Anyway, a Hypertherm and a good air dryer system is quite the investment to make just to "hope" that it works.  If I ever get a chance to use this machine again, I think that I'll figure out how to dry the air first.  In the end, my thought is that keeping one's air dry must be as important as everyone says it is.  Other than enclosing the machine in a room that had a big dehumidifier in it, I had nothing else to dry the air with.  I used our Makita portable electrical compressor to supply the air (85 psi), which it did quite well, but, once again, no air dryer in the system. Perhaps a tank of air instead of a compressor (just to test with)?  Any thoughts?I believe that banking institutions are more dangerous to our liberties than standing armies. - Thomas Jefferson