No announcement yet.

anyone run pre/post flow on MM252 for steel?

  • Filter
  • Time
  • Show
Clear All
new posts

  • #16
    Kevin, which heavier gun did you get for your 252, and do you like it? I'm teetering between a Bernard Q300 and a Roughneck 300 amp to replace the M25 gun, both seem to have their good points. I also want to get a "Y" for the C25 tanks, so I can set up my 30A gun for .023 hard wire for tacking/sheet metal, and probably keep using .035 Lincoln hardwire on the mig gun (I don't do aluminum at all, at least not yet)

    That way, I can just pick up whichever gun I want to use and touch the trigger and go.

    I'm not a for hire weld shop, just my own stuff - but I have a LOT of projects to finish for all 3 tractors before spring, may make it if I'm lucky... Steve


    • #17
      If you want real spray, and no short arc then is always 98/2 thats 98% Argon and 2% oxygen. Pretty much anything with a CO2 blend is globular transfer and short arc. Now Globular transfer sounds like spray but isn't true spray.

      As for pre and post flow, maybe 0.2 and 0.2 any more and its kinda a waste of gas, unless its areal heavy weld, in which case increase the post fow slightly. Robotic aplications use this function, but few operators use it


      • #18
        Cruizer, thanks for that - from my research so far, spray still seems to wanna "stay in the shadows", meaning that nobody wants to explain much about it - so far I've learned enough to "say no to spray", for any of my applications. Don't like the position limitations is the main reason.

        I weld mostly mild steel, anywhere from .065 wall tubing up to 1" plate, some things I could probably lay flat for spray, but it's not worth the changeover hassles for a couple of cases.

        For now, I have a few extra bottles and am thinking about getting one of the smaller 80 cf ones filled with CO2 in order to compare penetration and spatter differences relative to C25 gas.

        Other than that, I see no advantage to anything but short arc. My old copper wound stick machine will do 5/32 7018 all day without me having to wait on duty cycle, it doesn't matter if the wind's blowing or not, and I have enough leads on it to reach 40-50 feet outside the shop door if necessary.

        Kinda thinking it's time to re-establish the KISS method here... Steve


        • #19
          hey buckit, if you go with co2, before hand, check the door chart for c02, compared to an argon mix., you will notice that the settings are lower for co2 on the same size material compared to 75/25. so unless you get a better gun, you will be going backwards, using a gas that gets even hotter. when i bought my 252, i cooked the thingy just above the nozzle after 5 minutes of welding, be it the first 5 minutes on a new machine. i have bought alot of equipment from my lws over the years, they swapped out a bernard q gun, its a 300 amp gun, i did a small job last sunday for a friend, a 95 chevy truck, the rear cab mount on the frame rotted off, i dont have a lift so i use the jack stand technigue, this was the first time that i used the new gun, it is big and heavy, not the gun for what i was doing, but, i dont do much of that any way, when i did my practice welds with the miller rep, i loved the bernard, it has a swivel option, you can turn the neck, and changing tips is a breeze, you dont need to be a mechanic to swap out gun parts like the gun that comes with the 252. as far as gas goes, some where in this country, there is this guy, i forgot his name, many people here will know of it, he is the go to guy on shielding gas,s, he has written books on it. industry has used his services for creating weld specs, i wish i could remember, any ways, his big thing about mig welding is very interisting. number 1, 75/25, for mild steel is not the best mix, 85/15 or 90/10, the 90/10 does need better prep before welding, and also, all of these special tri mixs are nothing more than gimmicks, i will try to find this info. kevin


          • #20
            Kevin, I'd like to stay away from TOO big and heavy, think I'll ask to fondle the bernard and roughnecks next time I'm pestering my LWS And yeah, I understand the CO2 runs hotter - that's partly why the heavier gun. I wanna see how it does on thicker steel, maybe I won't have to break out the 7018 for some of the heavier fab on the hoe/tractors..

            I think this


            is the guy you're talking about, I'm gonna have to read his stuff a few more times to let it sink in - problem is, my LWS doesn't have a lot of choices in mixed gases. Next time I'm there I'll have 'em either give me a list of normally stocked ones or at least write it down for a change.

            I was just there yesterday, got a couple rolls of .035 steel wire for the 30A gun along with a few tips that size and a smaller, 1/2" copper nozzle. The gun came with a 1/8" recess diffuser, I'll try it but I'm used to flush on the other gun.

            I'm starting on a 12' x 12' mobile "car port" shelter that'll be 12' tall, gonna set it up so I can drive under it with the 580 and pick it up/move it with the loader. It'll have corrugated f'glas roofing, and hooks for tarps on sidewalls.

            Seems like I spend half my time setting up tarps so they won't become bathtubs when I try to work on something during the (nearly endless) rain. Got a small stack of 2" .120 wall square tube today in 24' length, kinda hard to get two 12 footers out of a 20

            I'll hook up another c25 tank/reg for the spool gun and eventually go down to .023 wire on it, keeping the main gun for heavier stuff. Gonna set the 30A up then for sheet metal/tacking, main gun for higher power, and take advantage of the 252's auto switch memory... Steve


            • #21
              anyone run pre/post flow on MM252 for steel?

              Well I bought a Q size tank of Stargold C25 get home hook it up and...1600lbs; doesn't seem right. After a phone call to Manager confirmed should be 2200lbs. WT...

              Will need to return as empty and will get a full one.

              No way no how to get a 90/10 or 85/15 mix in this size tank.


              • #22
                that drives me nuts when you get a short bottle, i am over an hour to my lws, i go ape when i get shorts, i have a few small bottles kicking around, they cost about the same to fill as the 375 cu ft bottles, those small bottles are for the home owner/shop type of customer and they price it as so, i know it sucks to pay for leases, but it makes up on the price of gas


                • #23
                  forgot, ed craig, read his work, very impressive


                  • #24
                    eric, what about an S or K tank? That little one will only get you maybe 4 hours of "trigger time", maybe you're not as loaded up with projects as I am? I have one tank that small, use it just in case the bigger ones go dry on a long weekend. Kevin's right, most LWS's charge almost as much to fill a "runt" as the bigger ones... Steve

                    (Same thing with wire - last spool I bought was the Lincoln .035, in a 44 pound 12" metal spool - it was almost a buck cheaper per pound than the 33 pounders )


                    • #25
                      I'll say this, if you work in any shop that is pinching pennies and trying to make a profit they are not stick welding. I love the smell of 7018 and use it here and there still but there are really only one or two uses for stick. The main use is ASME pipe welding where it is required(mainly for risk of gas coverage with mig/tig in the field I would assume). The other areas would be structural on skyscrapers where wind is too much of a risk as well. I believe gasless flux core wire can be used in most applications now though. For me personally the only time I justify stick at my work is when doing a repair and it is virtually impossible to clean the root out perfectly and the weld refuses to lose all porosity do to small junk/rust/contamination when welding with wire. I will then put just the root in with 7018. The other time would be if a field mechanic is doing a small repair(under 20 minutes or so) where it doesn't justify setting up the suitcase. Now, on to what I find to be a good functional setup for most fab shops. 3/16" and bigger is almost always a gas shielded flux core wire(I use .045" Outershield Elite from Lincoln but there is an .035" outershield 71m available and if you do mostly big stuff 1/16, 3/32, 3/16 and even 7/32 wires are available I believe). I feel .045" is optimal and I believe it actually has a higher deposition rate in it's highest speed. Either way, when I use gas shielded flux core it's almost ALWAYS CO2. I have used c25(75/25) and technically the tensile strength is higher but with co2 the ductility is better. This means that with co2 you are less prone to cracking. I have welded plenty of buckets this way with c25 and when you work for large companies that use a pc400 or bigger for a hammer yet they have a bucket installed the weakest link breaks. I have only ever had adaptors/shanks break with 75/25.....never with co2. I am not saying all of mine did, but whenever a shank weld broke whether it was mine or some elses it was welded with 75/25. Rarely did I ever see any broken co2 or 7018 stuff. Stick is just a slow, painful process and there is a reason no manufacturers still use it(do you see any cat parts from the factory welded with stick?). I do see the people that don't "trust" flux core and weld the "important" stuff with 7018 but at the same time these are usually the guys that insist on doing a 100% beverl on a 1/2" plate, welded to a 3/4" plate and then a 1/2" weld to hold that 3/4" plate to a 1/4" tube.....they don't know what they are doing. I see it at my work, I see it online. co2 has a bad reputation but in reality when you get a parameter guideline from the consumable manufacturer and set it up right it leaves probably the prettiest bead around and is EXCELLENT for vertical and overhead. Sorry for being long winded but you can't be afraid to try the new. Why not have a seperate , smaller mm210 or 211 around for your sheet metal work? Dave


                      • #26
                        "Why not have a seperate , smaller mm210 or 211 around for your sheet metal work?"

                        Dave, that's where I would like to be eventually - There are times (a LOT) when I wish I'd kept my 211 when I bought the 252. Only down thing about retirement is my "toy budget" - takehome is right at HALF what it was before I retired.

                        Space has to be my next priority, too many of the larger toys sit outside - not good for them, not good for ME especially when I need to work on 'em. That's why this summer I'll be adding 32' x 60' to my main shop. Still gotta cut about 50 yards of material out of one corner of the pad, already moved about 125 yards before the rain (read slimy gumbo clay crap) stopped me.

                        So for now, I'm trying to get the most out of the dual setup on the 252 - since I'm not interested in aluminum ATM, I figure putting .030 hard wire in the 30A and (after I use up about 40 pounds of the spool of .035 in the machine) going to .045 Outershield/CO2 on the main gun should be a fair compromise. Dual running gear lets me use whatever gas I want for each.

                        As pointed out, for the dirty stuff there's still 5P or 7018 stick... Steve
                        Last edited by BukitCase; 01-19-2014, 10:39 AM.


                        • #27
                          anyone run pre/post flow on MM252 for steel?

                          Biggest I can go (due to workbench height) is 41". I want to store the welder underneath the work bench.

                          The Q tank is 31" plus valve and reg/flowmeter.

                          Plus I can purchase this tank.

                          I think 4 hrs of trigger time should last me at least a yr as I rarely continuously weld for more than a few minutes.
                          Last edited by ericher69; 01-19-2014, 06:03 PM.


                          • #28
                            hi men, back at ya, another day of snow clean up. i am commenting on jerseys say on soft wire with co2, it definately has replaced stick in todays industries, i use alot of stick, but i am a small 1 man repair shop, alot different than large fab shops, in the 70,s i worked in calif in the big fab shop enviroument, soft wire and co2 were the rule, in the 80,s i was up in maine welding in the ship yards, 7018 is king on the out side of the ship, especially butts but the soft wire with co2 was coming into play around that time. for a hobby guy or small pro, flux core can be more than one would need on a usual basis, if i was to get one bucket after the other, each day, i would invest in it, but then i would need to build a bigger shop to keep the jobs out from the wind, at 61, putting up a new structure to get more work, really sounds like, way too much work


                            • #29
                              "putting up a new structure to get more work, really sounds like, way too much work"

                              Kevin, you're right - I'm 68, so I'm "putting up a new structure to get more PLAY "- it's a whole different dynamic

                              Eric, sounds like the small tank is fine for you - I've used that much in a day or two, my main c25 tank is a 200, the backup is an 80 - the older you get, the less time you think you have, so I'm "gettin' it while the gettin' is good"... Steve


                              • #30
                                anyone run pre/post flow on MM252 for steel?


                                Good for you!

                                I will charge accordingly to compensate for the more expensive gas!

                                It's mostly for my/family use but I do get co workers wanting small jobs done that big shops will not touch.

                                They don't mind paying if it means having it done sooner than later