Noob question about Argon/Co2 mix and pure Co2

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Hey there,I have a Lincoln Mig SP-140T (110V) and I've been using the Flux-cored wire and it's been okay.I am starting to do a bigger project which is welding a Car-Port (awning)/Shed type structure that will contain 4 main support and there will be aluminum corrugated panels on top.  I was wondering if I could use Flux-core (.30) wire to weld the square tubing and the frame. The main tubing supports are about 4x4" and I believe the thickness is about 1/8 - 1/4".  The framing would be like 2x2" and maybe 1/16" thick to 1/8". Okay, so I have that Lincoln SP140T and it comes with the Gas Hose for MIG with the regulator.  Now All I need is the Tank of Argon/CO2 mix OR just pure CO2?I don't know the difference between the two types of gas combo and what they are used for, can you please explain briefly. And do I need a Male or Female type fitting Nozzle on the Tank that I will purchase? Remember, I have the Lincoln SP140T and what ever it came with. Now, I think that the flux could do the job, but I am spending $1,000 on materials and don't want the WIND to knock over this car port and damage my cars. My buddy built his and had a friend weld the structure for him, so I thought I could try to do it as well.  I think Flux would hold the structure, but I don't want to take chances! Do it right the first time kind of thing.Thank you!Last edited by Absolutist24; 06-11-2009 at 06:07 AM.
Reply:First that machine is underpowered for that sort of job. IF you want to get the max penetration out of it you will see that generally according to the instructions you get the best penetration with flux core.Argon /Co2 is "cleaner" and produces less spatter than CO2. It also doesn't penetrate as much as 100% Co2, so it's better for thin materials. That said you can weld thick materials with argon/Co2, you just need to ramp up the power a bit more to get the same penetration.Co2 is generally cheaper than argon/Co2 mixes. That's the predominant reason most use it. You also get a bit more penetration than with argon mixes, but you get more spatter.I believe that unit comes with the regulator for argon/co2. If you want to run 100% Co2 you need an adapter or a different reg.Just remember structural projects with over head items are poor projects for learners. If you get snow there can literally be tons of weight above your head relying on your welds to keep it there. If you can not make code acceptable welds, DON"T DO THIS! Since you ask the question, you are most likely not ready for this job. Hire someone who is please. A car is cheap to replace, (your insurance may not cover the loss if they find out the welds were bad and you did the work) A persons life, especially that of a loved one is irreplaceable.
Reply:Originally Posted by DSWFirst that machine is underpowered for that sort of job. IF you want to get the max penetration out of it you will see that generally according to the instructions you get the best penetration with flux core.Argon /Co2 is "cleaner" and produces less spatter than CO2. It also doesn't penetrate as much as 100% Co2, so it's better for thin materials. That said you can weld thick materials with argon/Co2, you just need to ramp up the power a bit more to get the same penetration.Co2 is generally cheaper than argon/Co2 mixes. That's the predominant reason most use it. You also get a bit more penetration than with argon mixes, but you get more spatter.I believe that unit comes with the regulator for argon/co2. If you want to run 100% Co2 you need an adapter or a different reg.Just remember structural projects with over head items are poor projects for learners. If you get snow there can literally be tons of weight above your head relying on your welds to keep it there. If you can not make code acceptable welds, DON"T DO THIS! Since you ask the question, you are most likely not ready for this job. Hire someone who is please. A car is cheap to replace, (your insurance may not cover the loss if they find out the welds were bad and you did the work) A persons life, especially that of a loved one is irreplaceable.
Reply:Absolutist, your beads look a little too cold. Have you ever tried to bend a test weld to break it and look at the penetration? Also, gas is not the way to go for outdoor work, the wind will drive you nuts blowing the shield away. BTW what wire and size have you been using?
Reply:I agree they look cold and or run too fast. Both of these are common beginner mistakes.I'm guessing the steel is about 1-8"- 1/4" thick from the picts. Set the welder based on the info on the door or set the heat at max wire speed at about 2/3-3/4. It weld should make a crackling/ frying sound when the speed is right. Then skip the fancy moves and just drag the gun, ie point in the direction you have already welded and move slowly towards where you want to go pointing backwards, say 1" every 10 seconds (hard to relly say how fast with out actually doing it). Also clean the steel before you start, grind off all the rust, paint, slag etc.Last edited by DSW; 06-12-2009 at 10:20 PM.
Reply:Based on the beads (sort of) I'm seeing and the fact that the machine is underpowered for the job at hand, please have a qualified welder do the structure for you.You might find someone who would let you do the fitup and tac it together and he finishes it up.  Would possibly save you some money.Syncro 250 DX Dynasty 200 DXMM 251 w/30A SG XMT 304 w/714 Feeder & Optima PulserHH187Dialarc 250 AC/DCHypertherm PM 1250Smith, Harris, Victor O/ASmith and Thermco Gas MixersAccess to a full fab shop with CNC Plasma, Water Jet, etc.
Reply:I can't believe ya welded that File Coulda saved it and used the Higher carbon steel for a Tool.Anyhoo- as already mentioned... a lot of practice before attempting a structure.Tools you need:Safety Glasses4-1/2" Grinder- Minimum 2Flap Discs- on Grinder #1Grinding Wheel- usually comes with the GrinderWire Brush Wheel- on Grinder #2Face Shield- first time you get a scud off of the Wire Brush stuck in yer face you'll understand.general rule: Drag with FCAW (Fluxcore)Push with GMAW (Solid wire and gas MIG)Have fun.Ed Conleyhttp://www.screamingbroccoli.com/MM252MM211 (Sold)Passport Plus & Spool gunLincoln SP135 Plus- (Gone to a good home)Klutch 120v Plasma cutterSO 2020 benderBeer in the fridge
Reply:More heat!    Turn the volts all the way up and adjust the wire speed so you get a nice smooth arc.  You can do adjust wire speed while welding.Grind the plate clean before welding.Skip the circles and weaves.  Run stringers going the speed the puddle wants you to go.  Just watch it.  When you are done with a bead, clean off the slag and look at it.  Repeat...Back hand or drag, Make smooooth beads.  Burn up some of that wire!David  Last edited by David R; 06-14-2009 at 02:30 PM.Real world weldin.  When I grow up I want to be a tig weldor.
Reply:This may help. Let’s say the base stock is 1/8 inch thick and you are using 0.030 wire.The rule of thumb is one amp for every 0.001 inch of thickness. 1/8 in = 0.125 in. needing 125 amps to weld. How fast should the wire speed be?The conversion factor for 0.030 wire is 2.125 amps x 2 inper min/amps = 250 inches per min. Set up; if you can, turn the voltage control off. Set the wire speed at some number on the dial and pull the torch trigger for 6-sconds, count, one-thousand one, one thousand two…… adjust the wire feed for 25 inches in 6 seconds. That should get you in the ballpark for the wire feed. There are some excellent videos on MIG and FLUX CORE.PS, the wire stick-out should be 1/2 to 1 inch and pull the torch. The closer the torch is to the pool the hotter the arc. but not too close or you'll weld the wire to the tip.Last edited by transit; 06-14-2009 at 03:52 PM.
Reply:Looks like you were practicing on some galvanize. If your welding on galvanize you need to take a grinder and remove the coating, it will weld alot better, but your better off getting some mild steel and removing the mill scale,rust,dirt, etc to practice on.  Remember galvanize is poisionous so take caution when welding.  I'm a welder for a metal building co.and after the hurricanes last year I got to see alot of damaged patios and carports that the homeowner put up and was damaged because of  either there was not enough concrete around the post (not deep and wide enough) and the winds just lifted the whole thing or the welds failed,if you would call it a weld. One customer said the winds hadn't reached 60mph and his patio was rolling across his pasture. He said he saved $3000.00 by doing it himself. Good luck with your project
Reply:Fluxcore wire has enough energy to cut through the galvanized and the flux tolerates the contamination of the galvi.  I'm not allowed to grind off any of the galvanized or red protective coating on the metal framing I weld for the contractor I'm welding for and galvanized sheet and red coated iron beam is all I weld for the whole project, alot of it.  These are gov't buildings we're putting up and all this is according to code.  I wear a respirator and the galvanize doesn't bother me.   Now for solid wire and gas, it is a good idea to clean off all rust, coatings, etc, as those can contaminate the weld.  Solid wire and gas is not as tolerant to contaminants around the weld.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Hey guys, Thank you for the inputs. Okay, so the tubing that is being welded on is a piece of fence that probably has a thickness of 1/8". The metal piece which is about 3/16". The file had a broken handle and these were the only scraps I had laying around the yard.So I checked the chart on the Lincoln migs Door, It said according to the metal to use "B" at 1.5 feed speed. So that is what I used. I constantly adjusted the feed from 1.0 up to 1.5. I guess I should use a higher volt to C, or D, or max. For all the welds I used the Dragging starting from LEFT and moving to the right. The wire that was used is .030 Fluxed.I think you guys are right, I'll keep messing with the machine until I get familiar with it. I'll just not look at the chart and just FEEL and Listen to that Zipping sound. It's like driving a car, after a while you get used to your car and how she performs. OH, in addition, i was being a lazy *** by not grinding down the surface before welding, which even a noob like me knew it was wrong...but It's practice and i'll do better next time. So, thank you very much and always appreciate that good advice!!!
Reply:Find a welding class at a community college!  It is amazing how much metal and welding stuff you can go through for the cost of tuition..  Just materials you use can cost more than taking the class...  Price it out!