 ArtMetalsocial networking for the metal arts |
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cutting and marking
gillis -
Saturday, July 19, 2008 - 7:53am
plasma cutting Hi every one, I was asking in an earlier post about what kind of shade I would need for plasma cutting. So I went and both a pair of grade 5. Since they are quite dark, I was wondering, what should I use to trace the contour of the piece I want to cut. If I use, for exemple a black marker, I'm not sure I will be able to see enought to make a precise cut. What would you use for marking and tracing? gillis  Hi Gillis, are you using a
eligius1427 -
Saturday, July 19, 2008 - 10:52am
Hi Gillis, are you using a drag tip or machine tip for your torch? Unless i have a jig or straight edge, I always use the machine tip on my plasma cutter. I have to use a shade 8-9 because of the exposed arc(shade 3-5 glasses under a shade 5 face shield), but I can free hand much better with it. I mark my cuts with a white paint marker which i can get at local hardware stores. The contrast shows up great in the light from the cutter. Just make sure the paint has dried be for you start cutting, otherwise the air from the torch blows it all over and you lose your line. Jake  machine, drag tips?
man of mettle -
Saturday, July 19, 2008 - 3:26pm
hey jake, what is the difference between a machine and drag tip? i have a hypertherm.. it requires a gap between the tip and the metal. i have a fitting that slips over the torch head and has wheels, which allows me to keep the distance and follow a straight edge. keith Hi Keith, a machine tip
eligius1427 -
Saturday, July 19, 2008 - 4:30pm
Hi Keith, a machine tip sticks out farther than the shield and requires you to maintain a consistent offset from the steel. With a drag tip, the shield sits further out than the tip, creating the appropriate offset. You just set it on the metal and drag it across. When I learned how to use a plasma cutter the drag tips were huge, but now they're pretty slender. The great thing about drag tips is that once you learn the distance to the inside and outside of the kerf, you can make jigs out of 1/8" MDF board or use a straight edge to make very accurate cuts. With a straight edge I can make a cut within 1/32" which is handy since i don't have a shear. Jake  Gillis: For marking on dark
Rich Waugh -
Saturday, July 19, 2008 - 7:26pm
Gillis: For marking on dark metal like steel with mill scale, I usually use a "white-out" pen. It will hold up well to the heat and stays white. It aslo has the advantage of making a finer line than the paint pens they sell someplaces. The biggest help for seeing what you're doing when cutting or welding is to have very high ambient lighting. If you go outside in the sunlight, you will see that you can pretty much read a book through that #5 lens, as long as the page is in direct sunlight. Well, the same thing work indoors, too. I built a floodlight for using at the welding bench (and also for photography), that works really well, enabling me to see small detail through my welding helmet.
The floodlight is built of twelve (12) surface-mount light sockets mounted in a wood "reflector", painted white. I use the 13 watt compact fluorescent bulbs, and have the light wired so I can turn on four, eight or twelve lights at once. It really puts out a bunch of light with all the bulbs lit, but only draws about the same current as a 150 watt incandescent bulb. Since it is about 12x18 inches, it puts out a very soft, shadow-free light good for both working and photography. |
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ArtMetal
White soapstone. Sharpen it
White soapstone. Sharpen it on the grinder and use a very light touch. Shows up nice in the light from the plasma arc. I also use red, yellow or white steel marker pens.
If the metal is scratch free or you have machineist blueing you can use a sharp center punch or an awl for a very fine line.
Or on those "other" days just close your eyes and go for it!!!!!