|
|
I just got my Miller Mig 251 set up. I had a (dead) Century 145 and had some Mig Gas left from it, four years ago. The used 251 came with (1) Brown Cyl., it's 100 % Argon, and for ALU. Welding ?, the spool gun was set up with ALU. Wire.My (2) Cyls. are Light Green, I think this is what I read on the bottle tags > 92 % Argon, 02 % OXY., 06 % CO2.My Question:I'm welding 99 % Steel, mostly welding... add on stake pockets on a 40 ft. trailer, Welding 1/4 to 3/8 steel. I will be refilling my two gas bottle's... what Mig Mix do I want for Steel Welding AR ____/ _____CO2____/? ____ Gas ?Thanks,Avery ** Live Life as If There's No Tomorrow, then, You'll have a Number of Remembrance Smiles as You Prepare to Meet your Maker **Miller(s) 251 w/ Spool Gun 30 A, Big 40, Trailblazer 250 G.; IdealArc 400, SA-200, Classic SA-300, High Freq. Tig., LN-25.
Reply:Interested in hearing responses as there are so many opinions on the topic. The standard mig gas for short circuit mild steel that meets in the middle for performance and aesthetics is 75% argon and 25% CO2. 100% CO2 is cheaper, but it's hotter, so thin stuff becomes more difficult. There's a lot of spatter which generally sways people away from it. Other mixes of Ar/CO2 are used for spray transfer. I've read that 90/10 is the best all around gas because you can go both SC and spray, but I'm sure many will disagree with that statement.TA Arcmaster 300CM3XMT 304S22P12 suitcase feederX-Treme 12VSOptima pulserTA161SMaxstar 150STLHypertherm PM45OP setupStihl 020AVP, 039, 066 Magnum
Reply:ask the manufacturer of your welding wire. optimal chemical composition and mechanical properties is only guaranteed for/with a certain shielding gas.Now that's theory. In practise, 80/20 to 90/10 is used for 99% of MAG welding (mind, I'm talking mag, not mig) of "normal" ( = construction) steel.
Reply:I usually run about 60% CO2 to 40% argon.Its cheap, makes for good weld penetration with not much splatter.If you mix your own gas and occasionally run flux core like me you can run a little CO2 coverage (5 to 10 liters per minute) and cut way down on the spatter.I always figured mix C25 was common because if you put too much CO2 in with the argon and try to compress it up to 2200psi the CO2 will start to condense out.The wire I use is intended for 100% CO2 and C25. Whats so bad about being some where in the middle of those 2 mixes?I did notice that unprotected C25 welds rust less than my C60 or C70 mix when they get rained on.There is a sticky at the top of the forum that breaks down various CO2 with argon mixes. Usually a higher CO2 mix is associated with high speed production line mig welding.C25 and higher C mixes only work on mig and steel.See:http://weldingweb.com/vbb/showthread.php...gas&highlight=old Miller spectrum 625 Lincoln SP-135 T, CO2+0.025 wireMiller model 250 and WP-18V torchCraftsman 100amp AC/DC and WP-17V torchCentury 115-004 HF arc stabilizerHome made 4 transformer spot welderHome made alternator welder
Reply:The mix that you have (6% co2, 2% O2) is good for spray transfer but not good for short-arc. It will work very poorly for welding out-of-position because it makes a hot arc and a very fluid puddle.Since you have 2 tanks, I would keep one with that mix for flat and horizontal welds on heavy steel, and fill the other with 75/25 for general short-arc welding (thinner metal and/or out-of-position welds).If you are welding mostly 1/4" and thicker you may also want to try gas-shielded flux-core, AKA dual-shield. It is easy to run out-of-position, and really lays down the metal. There are types that are made for 75/25 or 100% CO2, and types that will work with either gas.JohnLast edited by Silicon-based; 12-09-2013 at 10:07 PM.Reason: ClarityA few weldersA lot of hammersA whole lot of C-clamps
Reply:John & All,Good Info. (above), to advise me on the type of gas mix I need for the steel welding job I'm doing now. The mig gas (left over) I have was used to weld 3/8" steel guide rails to ramp up a low boy trailer. The ramp up (tapered ht.) rails increased the roll up of the low boy to the correct height; this allowed the 5th wheel to lock up to the trailer king pin. The old Century 145 did a fair job with -- 92% AR, 02% OXY, 06% CO2 Mix (flat welding). Avery** Live Life as If There's No Tomorrow, then, You'll have a Number of Remembrance Smiles as You Prepare to Meet your Maker **Miller(s) 251 w/ Spool Gun 30 A, Big 40, Trailblazer 250 G.; IdealArc 400, SA-200, Classic SA-300, High Freq. Tig., LN-25.
Reply:I use 92Ar/8Co2 for spray transfer welding. Tried 98Ar/2Co2 as well, spray transfer is very easily achieved with this mix.Went back to 92/8 because of better wetting/fluidity properties of weld.For short-circuit I use 82Ar/18Co2. This mix may also be used for spray transfer in a pinch, but the arc is rather unstable...Cheers,Last edited by Hoybaronen; 12-15-2013 at 08:20 AM.Migatronic Omega 300 BoostMigatronic Pilot 130 ERilon TIG 200G Ac/DcRilon Cut 60 MOSAGA X11 O/A EquipmentLagun FU 1250 universal millerMondiale Gallic 16 latheStrands SB 68 Drill press
Reply:I believe it was 1985-ish when the welding shops started turning their victims on to C25. It's far superior to pure argon on MIG, PROVIDED you machine has some ascz !On the 140 and under "toyz"...as much as I HATE to admit it, you're far better off with flux core.Bubble gumTooth pixDuct tapeBlack glueGBMF hammerScrew gun --bad battery (see above)
Reply:@ HighFly27 - recommend you select a shielding gas based on what your LWS can obtain/provide. What? Why? My LWS can only provide 100CO2, 75Ar/25CO2 ("C25"), 90Ar/10CO2, and 90Ar/2O2. Commonly, the first two mixtures are for short-circuit on mild steel, while the second two mixtures are relegated to axial spray on mild steel. There are minor exceptions supported by the literature and experienced welders here. In addition, LWS' also decide what gas they will provide to LWS-owned (customer-leased) cylinders and customer-owned cylinders. Size and ownership of cylinder does matter. Asked 'em to fill their 155CF (customer-leased), with 98Ar/2CO2 or even 95Ar/5CO2. No dice. Settled on 98Ar/2O2. In your case, would suggest one cylinder of C25 for short-circuit and one cylinder of either 90Ar/10CO2 or 98Ar/2O2 for axial spray. Simple. Basic. You do not need any tri-mix for mild steel. Also learned from 'Dan', other WW crew members, and personal experience that using a single mixture for short-circuit and axially spray is undesirable. Trade offs in performance abound.Certainly the short-circuit wizards and spray arc warlocks here will supply you with additional insight.Last edited by ManoKai; 12-15-2013 at 10:13 AM."Discovery is to see what everybody else has seen, and to think what nobody else has thought" - Albert Szent-Gyorgyi
Reply:Good point about cylinder size. I can get just about anything in a 300 cu. ft. tank but mostly just 75/25 or straight Ar or CO2 in smaller tanks.A few weldersA lot of hammersA whole lot of C-clamps
Reply:Same problem here in Norway. Only 82Ar/18Co2, oxygene and acetylene in self-owned 10 litre bottles (bottle volume).Had to lease a 50 l bottle for the 92Ar/8Co2. Until a few years ago one could order custom gas filling in self-owned bottles.But not anymore... Migatronic Omega 300 BoostMigatronic Pilot 130 ERilon TIG 200G Ac/DcRilon Cut 60 MOSAGA X11 O/A EquipmentLagun FU 1250 universal millerMondiale Gallic 16 latheStrands SB 68 Drill press |
|
发表于 2021-8-31 22:38:32