Plasma Cutting Square Tubing

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Hello All....Yesterday I tried cutting a piece of square 1x1 16 ga tubing with my plasma cutter.  Top looked good and the sides looked ok, but the bottom was a mess.  I used a straight edge on top as a guide.  Plasma was set at 50 amps, 70 psiI was hoping to find away to use my plasma cutter instead of the abrasive chop saw.Any suggestions?  Should I forget about using the plasma on square tubing and stick with the abrasive chop saw?MetalBob
Reply:No practical experience with the plasma, but I would think like oxy-acetyline cutting you would have to keep the tip close to your cut. If you are trying to cut through the bottom from the top it'll be a mess is what I'm thinking. make your three sided cut, then turn the tubing 1/4 or 1/2 turn for the final cut. Good luck!If you don't have the time to do it right, then you definitely don't have the time to do it over.
Reply:50 amps seems high for 16 gage.  That current on most plasma cutters will sever 3/8 inch.  I'd try backing down on the amps.TeddCoHTP Microcut 400 & Invertig 160DC  Smith Dual Guard MD-510 OA Rig  Lincoln SP135+  Hobart Stickmate LX 235/160
Reply:Both of the above.DennisThermal Arc 185-TSWMillermatic Challenger 172VictorO/AAtlas Craftsman 12 by 24 LatheEsab PCM-875Wholesalem Tool Mill-Drill
Reply:I bought my first plasma cutter just a couple of months ago. A ThermoDynamics cut master 38. I spent a little time with some people showing me the ins and outs. I do not believe that you can cut tubing or pipe in a single pass without rotating it. The torch tip should have a proper heigth setting and the space inside your tubing would kill the arc. According to the manuals of several plasma cutters I looked at, you set the amps to max, cuts speeds are what change with the material thinkness and type. If you have allot of tube to cut. You could look for a power band saw. Their cheaper to run as the blade life it allot longer and you don't have all the sparks and mess to clean up. Plus the dust and dirt are hard on the loungs. I used to cut everything with a chop saw and unless I am out in the field, I will never use one again. Also with a power band saw you can cut more steel at a time and do somehting else while it cuts.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:Originally Posted by jamlitI bought my first plasma cutter just a couple of months ago. A ThermoDynamics cut master 38. I spent a little time with some people showing me the ins and outs. I do not believe that you can cut tubing or pipe in a single pass without rotating it. The torch tip should have a proper heigth setting and the space inside your tubing would kill the arc. According to the manuals of several plasma cutters I looked at, you set the amps to max, cuts speeds are what change with the material thinkness and type. If you have allot of tube to cut. You could look for a power band saw. Their cheaper to run as the blade life it allot longer and you don't have all the sparks and mess to clean up. Plus the dust and dirt are hard on the loungs. I used to cut everything with a chop saw and unless I am out in the field, I will never use one again. Also with a power band saw you can cut more steel at a time and do somehting else while it cuts.
Reply:Originally Posted by MetalBobHow does a portable band saw compare to an abrasive chop saw - more or less dust?  Which is louder?  I have never used a portable band saw.  Can you position it against a straight edge?I will try less amps and rotating the piece and cutting twice.  But, at that point, it seams like it may be easier to just deal with dust and mess of the abrasive chop saw.  Yes or no?So, of the three cutting tools - Plasma Cutter, Abrasive Chop Saw, or Portable Band Saw - which is the easiest to size and cut square tubing 1/8 to 16 ga. wall?Thanks for your input....
Reply:The bandsaw is far better than a chopsaw. Cleaner cut, Less clean up of the cut area, no dust, and much quiter. I do not believe less amps are going to help. The arc on a plasma cutter is limited to depth and can't cut through steel that has spaces between its layers. I tried cutting sheets of steel stacked one on top of the other and anywhere there was any space between the layers the buttom sheet didn't have a nice cut. The space between the sheets was only about 1/8. If you set up your materail on some sort a rotating machine, you might be able to cut tubing with the plasma. I might add that when I do allot of cutting with the plasma, I get allot of fine black dust everywhere. This make the band saw even better when doing straight on angle cuts but I love the plasam for doing design cutting.Hope this helps.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:i agree, i've gone through two chopsaws, now i have a crappy hf bandsaw.  used a portaband forever.  given the two choices you have, you'd be better off using the chopsaw.  but do yourself a favor and get a stationary bandsaw and a portaband.  if you don't have a use for the portaband now you will when you get it.  only problem with thin tubing and a bandsaw is that it will strip the teeth out of a blade that's too rough.  a blade with enough tpi for 16 gauge tubing will take forever on inch square stock.  milwaukee sells an attachment for their portaband that turns it into a stationary saw, i've never used one and so i have no opinion on it whatsoever
Reply:Great info guys.....Thanks!Band saw sounds like a nice idea, however, space is limited.MetalBob
Reply:Also, in regard to using the abrasive chop saw, should I wear a dust mask?It seams like my lungs feel after I make about 10 cuts or so...MetalBob
Reply:Yep I agree for my general cuts for spec... so much quieter I go to my stationary band saw. weld it like you own it
Reply:As far as wearing a dust mask ... yes I always do or at least the ole bandana like robbing a train weld it like you own it
Reply:By the time you buy a decent bandsaw for metal you could probably get you a really nice cold saw with a good carbide blade that will cut the smaller square tubing just fine.  The cold saw produces chips of metal and there is a lot less dust and fumes.  To me its kind of a cross between the bandsaw and chop saw. You get the clean cut of a bandsaw and the convenience of lopping off tube stock like a chop saw.  Downside...the cold saw is pretty loud.just my .02 centsMichael
Reply:I always wear a dust mask. Loungs can't take the abuse anymore when inside. 383bigblock's idea of a cold saw might work for you. They do a nice job, take up the same space as a chopsaw and allot less dust and diry, I prefer the band saw because its cutting while I am welding. Let us how you decide.Miller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:If you all dont mind my asking, what is a 'cold saw' ??I have used a horizontal pivoting bandsaw with auto control for rate of drop and it made nice clean cuts but it was kinda slow and the cutting oil used to cool and lube the blade is an annoyance to clean out of the tubes before welding and adds to the time and work needed for metal prep.   I prefer cutting with the abrasive chop saw, although the cuts are not as accurate as the band saw and they need a little grinding to prep them.
Reply:I think 383 was referring to a "Dry-cut" saw, not a "Cold Saw".Cold saws are great but are very expensive.They run at really low RPM with a steel, carbide tipped blade and a flow of coolant on the cut while the blade is spinning. The cuts are extremely accurate, there is no dust, and material is almost 100% burr free. A good brand name saw will cost $2500+A Dry Cut runs at low RPM with a steel, carbide tipped blade but has no coolant flowing. I have the Milwuakee version of this saw and I love it but be prepared....these suckers are LOUD!!!!! No dust but a lot of little metal chips. Cuts are very accurate and almost burr free. A good dry cut is about $400-$500.- Paulhttp://all-a-cart.comWelding Cart Kits and accessories
Reply:If you all dont mind my asking, what is a 'cold saw' ??
Reply:Thanks for the explanation!    I guess I have been calling 'cold saws' oil-bath saws or water-cooled saws.  The band saw I talked about earlier operated in an oil bath.  the oil was kept in a reservoir below the saw and pumped through a hose that washed it over the blade where it would then run back down to the reservoir.   I have used a tile-cutting 'wet saw' before too where edge of the circular blade ran through a reservoir of water.At work we use some very large semi-automated double-miter saws that use 14" dia. steel blades with diamond tipped teeth.   We cut aluminum extrusion with them and spray a very fine mist of lubricant (a few drops an hour) on the blades between cuts using air pressure to draw the oil up from a sealed tank through a small tube that sprays on the blade tips when the blades are retracted back into the saw while the cut part is being cleared from the saw and the fresh metal is being advanced into position for the next cut.   The saws are quite loud and do, when the blades are kept sharp and the saws are cutting straight, make nice clean cuts.   When we cut steel lengths, we use the manually operated mitered chop saw with an abrasive blade, or the vertical band saw, or a jig saw for smaller pieces that can be cut free-hand.   At home I use usually the chop saw, but like to use the air cut-off tool for smaller things and have recently used the angle grinder with a cut-off blade thanks to the tip from you guys here!   We have many other tools to cut steel like the sawzall, hack saw, few different die grinders, and the jig saw, probly a few others I rarely use and cant think of at the moment.  I use the torch for bigger stuff but soon I hope to be using the new plasma cutter (  ) on solid stock or plate.  It is rated for 7/8" and supposed to sever up to 1-1/4" (55 amps output at 110v DC, using 33 amps connected to 230v single phase line.).  I'll soon find out, provided the auction I won turns out to be legit (I doubt it)....
Reply:Oh I forgot to ask, Paul do the 'dry cut' saws you taked about come in miter or compound miter configuration with 14" size blade for cutting steel?   I would like a more accurate way to make miter cuts on steel than the chop saw.  I've not seen a 14" chop saw with a good miter base except for the one at work but I havent found any info on the company that made that saw.  It is quite old.   The Makita chop saw here at the house works great for making straight cuts but not for miters.  It has a clamp that can be angled one way, but it isn't a very good clamping setup and isnt convenient to change back and forth either.   The wood cutting 10" and 12"  saws are available in some nice miter and compound slide miter configurations that make good cuts but I dont know that one for wood would last long cutting steel.   I would also like to have a 14" blade so tubes up to 4" can be cut.
Reply:We use a chop saw that was one of the first on the market years ago. I hate the mess and the noise it bad. But for what we paid for it and as long as it has lasted I cant complaine. If you go chop saw and I will give u a tip. Buy the blades for the gas powered portable chop. Like the one you see guys cuting re-bar and concreat cuter. Well the metel cuting blade for one of them are a little higher but will last 4 times longer.
Reply:I find if you are going to stay with the chopsaw rather than looking at a bandsaw, that Walter brand blades are the best. As dhardin53 posted above, good blades are worth the moneyMiller DVI2Lincoln Precision Tig 225Thermodynamics Cutmaster 38Everything else needed.
Reply:absolutely wear a mask. there is a respiratory disease called grinders disease from inhaling the dust from years of grinding.  personally i wear a mask just to cut down on the black boogers