Posted by Sherman in Idaho [24.32.202.166] on Friday, March 22, 2013 at 21:21:46 :
In Reply to: Lets talk Plasma cutters posted by Tim Holloway [69.54.28.229] on Friday, March 22, 2013 at 20:07:30 :
...but I actually like my $650-20% ($520) Harbor Freight plasma cutter. For heavy stuff or away from plug-in electricy, of course, I reach for the old Victor blue wrench. Cutting up a frame it might be a toss-up depending on which was more convenient. Either would work.
They are really quite different tools for different purposes. A plasma torch cuts stainless and aluminum, which alone makes it worth the price. It will cut very neat smooth lines in either one, or in thin steel, if you have the juice set right and have a straight-edge (or curved template) to guide the torch. Don't think of cutting anything anywhere close to smooth freehand. I cut a fair number of circular cutouts for meters and gauges in ~1/8" aluminum panels, and the plasma torch is just the ticket for that. I've accumulated a number of round things, from slices of steel pipe to jar lids, that can serve as templates (inside or outside) for cutting round holes.
I'm sure that I'd like a good brand plasma torch even better, but I like the torch I can afford that I have on hand better than the one I don't have yet because I can't afford it, but wish I did. I have pushed the harbor freight one pretty hard, on max amps setting, and never had it shut down due to overheating. Consumables are "probably" cheaper than the blue wrench, but plasma tips are not particularly cheap, and you will use some.
The main limitation of plasma is the depth of cut. Mine will cut 1/4" steel cleanly, but beyond that it runs out of steam quickly. I think I did some 7/16 tempered plate once, but that was pushing it to the limit and it left a very rough cut. It's not like oxy/acetylene where you can finesse it to get through a thicker piece occasionally. The old Victor will cut 1" steel like butter if the tip is clean and the oxygen pressure is turned up, and will cut railroad iron if you work it a bit.
The serious scrappers use oxy/propane these days because for cutting, propane is hot enough, and it's a lot cheaper than acetylene. So if your main interest is scrapping, and you never do any torch welding, you might look into that. I stick with oxy/acetylene because I can cut most scrap with the plasma torch, and I use the gas torch mainly for brazing, bending, welding in remote places where there's no electricity, and when I need to do a nice neat weld and warping isn't a concern. For now all I have in the way of a wire feed welder is a cheap one that only really wants to work half-decent at max power and max feed speed. I'll be upgrading that when I can afford it, but the current plasma cutter will probably continue to do everything I need.