75/25 or co2

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I have owned two 110v input (pocket mig's) and operated many.I own and or have operated GMAW power sources (PS) with up to 600amps 100% duty cycle. I have many years experience with hard wire GMAW short arc and spray arc. Wire sizes ranging .023-.062.   Enough bs ... I don't see using 75/25 on the pocket mig's. It increases the the cost of operation. I have not seen much improvement over CO2. On my Passport it actually degraded the performance markedly. On higher amp machines (say a MM251) or bigger while running .035 hard wire and 75/25 on vary clean steel (cold rolled sheet) the mix gas wets in the filler so much better, and a great reduction in spatter is noted. So my thinking is if you want to increase the performance of your pocket mig toss the gas altogether and get some NR211.Adding 75/25 to the pocket mig is like adding a headers and a cam to a Geo Metro, sure it can be done but why, you still have an under powered limited use machine. All just my opinion, agree disagree?
Reply:I have mixed thoughts on it. I usually did thinner stuff with my Lincoln 100. I was welding mostly .065 box tube to .120 tube with it, and then lots of small brackets on bumpers and truck racks. I had good results with the 75/25. I never really thought too much about straight c02, as I only got one small bottle of it, and I didn't like the look of the weld quite as much. But for welding the stuff where you are at the limits of the machine, then it would make good sense to do every last thing you can to step up the heat even a tiny bit.And then, after so much work...... you have it in your hand, and you look over to your side...... and the runner has run off. Leaving you holding the prize, wondering when the runner will return.
Reply:We use CO2 in our passport too, Didn't see any improvement with the 75/25 on that either.We have an old Airco with a Lincoln wire feeder that always has .035 on it. We use it for all the stuff that comes on for quick repairs where short arc .035 would work well, that also gets straight CO2. All it usually sees is crappy sheet metal so why spend the money on the mix? So beyond the small MIGs, we have found that the straight CO2 is "good enough" for alot of stuff.When we are fabbing something new we use a different welder with mix but for repairing crappy steel why bother with the mix?Yup
Reply:Ahhh, but C25 and a 120V MIG machine are a nice set-up for sheetmetal thickness work.  A one-ton pickup won't get 40 mpg, and the Geo Metro can't haul 6000+ lbs inside or 12,000+ lbs in a trailer.  Right tool for the job, and all that.    The best laid schemes ... Gang oft agley ...
Reply:My 110 weldpak can't run gas (complete impossibility) but for what it is intended for with fcaw it's a welding son-of-a-gun. The 220 weldpak has 75/25 on it and it works great. It is pretty much only used for ornamental stuff. I like the results better and I use much less gas. You have to find what you like and what works best for you. The only way to do that is by experimentation.The difference between art and craft is the quality of the workmanship. I am an artist.
Reply:Fat Bastard, I have a Lincoln Weldpack 3200 HD that I use on small stuff and have found the same as you about using mix compared to CO2. I also believe it works much better running the NR-211-MP wire, seems to burn hotter and has better looking welds and better penetration.Last edited by dabar39; 08-14-2008 at 09:23 PM.Reason: spellingI am what I am, Deal with it!If necessity is the Mother of Invention, I must be the Father of Desperation!
Reply:CO2 for every thing. It is 1/3 the cost of mix and it comes in liquid instead of compressed so lasts 3 times as long. For that I can deal with a little, and I mean a little, extra spatter.
Reply:Originally Posted by Fat BastardAdding 75/25 to the pocket mig is like adding a headers and a cam to a Geo Metro, sure it can be done but why, you still have an under powered limited use machine.
Reply:Originally Posted by BobCO2 for every thing. It is 1/3 the cost of mix and it comes in liquid instead of compressed so lasts 3 times as long. For that I can deal with a little, and I mean a little, extra spatter.
Reply:Originally Posted by MoonRiseAhhh, but C25 and a 120V MIG machine are a nice set-up for sheetmetal thickness work.  A one-ton pickup won't get 40 mpg, and the Geo Metro can't haul 6000+ lbs inside or 12,000+ lbs in a trailer.  Right tool for the job, and all that.
Reply:Originally Posted by dabar39Fat Bastard, I have a Lincoln Weldpack 3200 HD that I use on small stuff and have found the same as you about using mix compared to CO2. I also believe it works much better running the NR-211-MP wire, seems to burn hotter and has better looking welds and better penetration.
Reply:When using a 110 machine, and having limited volts, I use 75/25. The CO2 is not as good of a conductor of electricity as the 75/25. Allowing for slightly more from the machine.
Reply:Originally Posted by LA WeldDave, I will give that a try on my Passport and see how she does. Never run gasless on the Passport yet and if it does perform I will go that way in the future for sure..
Reply:Originally Posted by Broccoli1It runs sweet!!
Reply:I'm running .035 in mine and really like it.I am what I am, Deal with it!If necessity is the Mother of Invention, I must be the Father of Desperation!
Reply:I run CO2 for everything that I do, an excavator bucket, truck frame, or a dozer blade can' tell the difference. My brother bought a little 110 MIG for body work and he prefers the 75/25 for the thin stuff. Every gas has it's place thats why there are so many mixes.Disclaimer; "I am just an a$$hole welder, don't take it personally ."
Reply:I ran some .030I intended to try some .035 but got out to my buds place and didn't have the .035 tipsHe has a 100 acres out in the desert and we were attaching some Zinc Plated Hitching rings to some 1/4" 2"x2" Posts, but we don't go out there in the summer (100 + deg)  so I can't snap any pic of the small project.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:Thanks Dave and Ed, will check it out next week and see whats up..
Reply:As I had thought, this thread will be one we can all use to point newbys to for general thoughts about gas and GMAW  as well FCAW.Great job guys!TJ
Reply:Remember FB,The passport is a pretty sophisticated little box that has been optimized for CO2. It does a much better job with CO2 than say a MM140 would with that gas. You have been working with it for so long that you have perfected your technique. One reason MIG is so popular with C25 is that your little sister can put on a mask and pick up a mig gun and make an acceptable weld with little practice. "Very little additional spatter" in your hands would probably be a big difference in mine. BTW the reason they designed the passport to run on CO2 is because the gas can be liquified and stored in a small bottle inside the box. The idea was maximum portablilty in a gas shielded GMAW machine. It doesn't hurt that CO2 gives more penetration than C25 at the same settings. The passport is a great little machine but I love my MM180     - DrBob
Reply:I have a 110, and use mix for thinner stuff, and mix with preheating on heavier stuff and cranking up the feed, if I don't have the torch around for heavier stuff (1/4" max) I use .030 flux, I guess it depends though?, the first mig I ever bought was a lincoln 100, that thing wasn't worth a crap with the flux it worked ok as a mig on very light material, I use the miller 130 now and it's a lot better, I also had a lincoln 3200 home depot special and that thing wasn't half bad for light, quickies, not very good on continuous use though I think it had like a 30% duty on it, I'm sold on the miller products all the way. my neighbor bought a home depot 100 to make structural braces for his house, I laughed, he says "I've used these little ones at work for years on this kind of stuff" I guess he doesn't realize that you can get a decent machine in the same enclosure. If I actually thought the braces were of structural value (they're not in my opinion) I wouldn't let my kids in that house
Reply:I use a Passport on the truck with E71TGS flux-core wire in .030" size. It makes very nice welds with flux core with surprisingly little spatter if I have it dialed in just right.  I have used it with .030 ER70S6 solid mig wire and CO2 and it was great while it lasted!   I should have bought a 20# bottle of CO2 to run it on, but instead I use 85/15 Ar/CO2 mix gas when I solid wire mig with the Passport cause I went ahead and bought an 80 cf bottle to keep on the truck.  It welds fine with the mix gas, very little spatter, nice wet-in, but it welded so awesome with the CO2, I feel like I cheated myself going with the mix gas.   I have been looking for a good deal on a used CO2 bottle to keep on the truck.  The local welding shop wants alot of $$ for a new one, seems like more than they charge for regular gas bottles.  I could run it on CO2 with the little internal bottle that came with the machine, but it doesn't last very long, the tiny bottles are expensive to buy so keeping extras on hand is out and it's very inconvenient to run to the weld shop to fill the thing every time it runs out.  I would like to be able to fill the little bottle from a bigger one on the truck, that would be ideal.Last edited by DesertRider33; 01-11-2009 at 04:32 PM.MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op
Reply:Don't forget, Desert Rider, that CO2 fire extinguishers can be changed over to use for welding gas. It's just a matter of taking it to your welding supply and having them change the valve.
Reply:CO2 fire extinguishers... hmm... interesting.   Do they look any different on the outside than the powdery ones?MM350P/Python/Q300MM175/Q300DialarcHFHTP MIG200PowCon300SMHypertherm380ThermalArc185Purox oaF350CrewCab4x4LoadNGo utilitybedBobcat250XMT304/Optima/SpoolmaticSuitcase12RC/Q300Suitcase8RC/Q400Passport/Q300Smith op