mig and flux core tips and techniques, equipment, filler metal
User avatar
  • Posts:
  • Joined:
    Thu Dec 01, 2016 12:30 pm
  • Location:
    FL

I have to weld half-inch-thick gussets into a high-stress part made from half-inch plate. I can MIG okay, and I am pretty sure I can run 7018, but which one is better for this purpose? The part is a middle buster for a tractor. I bent the tabs that attach it to my hitch while I was pulling stumps. Today I straightened them, and the gussets are supposed to make them less likely to bend again.
I was socially distant when social distancing wasn't cool.
cj737
  • Posts:
  • Joined:
    Thu Sep 29, 2016 8:59 am

Bevel the plate and use whichever you prefer. I suspect Stick will get better penetration unless you’ve got a hearty MIG. Both process will need multiple passes. I’d be Stick, 3/32 root, cover with 1/8, 7018 the whole way. That’s just me...
tweake
  • Posts:
  • Joined:
    Mon Dec 18, 2017 4:53 am
  • Location:
    New Zealand

i'm a fan of stick for this sort of situation.

with stick you can weld outdoors which is handy for a tractor. its perfectly fine for what i suspect is short runs and if you stuff it up it looks like it.
tweak it until it breaks
User avatar
  • Posts:
  • Joined:
    Fri Apr 01, 2011 10:59 pm
  • Location:
    Australia; Victoria

If you have a big mig 350 amps or bigger, go for it. The world is welded with migs. But a decent stick welder, 180 amps or more will weld this. Jody said, with a 3.25mm stick rod, you can weld just about anything if you have time.
User avatar
  • Posts:
  • Joined:
    Wed Jan 22, 2014 12:00 am
  • Location:
    Connecticut

None of the above. I would use gas shielded flux core in the MIG machine. It gives all of the benefits of 7018, while being infinitely easier to run vertically or horizontally. Much hotter than standard hardwire MIG as well. If you need to stack in multiple passes, its no problem. If you have a smaller MIG, use 035 wire. In a larger MIG use 045 or thicker. Jody has a number of excellent videos of doing structural and pipe welding with 035 gas shielded flux core (aka "dual shield flux core") using the Lincoln 210MP

I have used the Lincoln 71M wire in 035 and 045. I really like it. Others have had good luck with Esab dual shield wires.
Multimatic 255
User avatar
  • Posts:
  • Joined:
    Thu Dec 26, 2013 12:41 am
  • Location:
    Laredo, Tx

Louie1961 wrote:None of the above. I would use gas shielded flux core in the MIG machine. It gives all of the benefits of 7018, while being infinitely easier to run vertically or horizontally. Much hotter than standard hardwire MIG as well. If you need to stack in multiple passes, its no problem. If you have a smaller MIG, use 035 wire. In a larger MIG use 045 or thicker. Jody has a number of excellent videos of doing structural and pipe welding with 035 gas shielded flux core (aka "dual shield flux core") using the Lincoln 210MP

I have used the Lincoln 71M wire in 035 and 045. I really like it. Others have had good luck with Esab dual shield wires.
I agree, especially if time will be of the essence, and if you already have a roll. 045 diameter at 300A will burn in real well (it won't go into spray-like transfer below about 240-250A). 035 would need about 200-220A IIRC.
Image
User avatar
  • Posts:
  • Joined:
    Fri Apr 01, 2011 10:59 pm
  • Location:
    Australia; Victoria

I should also mention that I would agree that you need. 045 diameter mig wire to weld that well effectively. The main issue being, the stick welding doesn't require any extra equipment except for bigger rods, and a finger capable of turning the machine up. Mig requires a big mig, flux core will maybe require different gas, and knurled rolls. Not to mention decent flux core costs a little bit more.
User avatar
  • Posts:
  • Joined:
    Wed Jan 22, 2014 12:00 am
  • Location:
    Connecticut

weldin mike 27 wrote:flux core will maybe require different gas, and knurled rolls.
I think most of the common gas shielded flux core wires call for 75/25. A lot of them will use either 75/25 or straight CO2. I wouldn't worry too much about the gas.
Multimatic 255
User avatar
  • Posts:
  • Joined:
    Wed Jan 22, 2014 12:00 am
  • Location:
    Connecticut

045 diameter at 300A will burn in real well (it won't go into spray-like transfer below about 240-250A)
I have never needed 300 amps for 045 wire (Lincoln 71M). At least on my MM252, I was always in the 220-240 amp range (26 volts, 300-350 ipm) and it worked wonderfully. Nice quiet arc, with no sputtering. What brand of wire do you use Oscar?
Multimatic 255
User avatar
  • Posts:
  • Joined:
    Thu Dec 26, 2013 12:41 am
  • Location:
    Laredo, Tx

Louie1961 wrote:
045 diameter at 300A will burn in real well (it won't go into spray-like transfer below about 240-250A)
I have never needed 300 amps for 045 wire (Lincoln 71M). At least on my MM252, I was always in the 220-240 amp range (26 volts, 300-350 ipm) and it worked wonderfully. Nice quiet arc, with no sputtering. What brand of wire do you use Oscar?
I have several rolls here: Lincoln 71M, Kiswel K71T, HTP E71T-1C/1M, Böhler. But I don't use it that often to be honest. Only burned a few pounds just to see what it runs like. My numbers could very well be off, just from going by memory. But you're right, 300A is not needed, but it sure does run wicked hot!
Image
homeboy
  • Posts:
  • Joined:
    Mon Dec 19, 2016 11:52 pm
  • Location:
    Southern Ontario Canada

Louie1961 wrote:
045 diameter at 300A will burn in real well (it won't go into spray-like transfer below about 240-250A)
I have never needed 300 amps for 045 wire (Lincoln 71M). At least on my MM252, I was always in the 220-240 amp range (26 volts, 300-350 ipm) and it worked wonderfully. Nice quiet arc, with no sputtering. What brand of wire do you use Oscar?
The only time I used .045 gas shielded fc, normaly use .035,(75/25) was welding spring hangers on a flipped over tandom trailer. By memory I think I was a volt or so lower, enough that the vertical weld didn't sag. It is hot! When I tested it on some 3/16 flat at about Louie's setting, 26V, 300ipm it blew right thru! When Blue Demon discontinued the 8in rolls I switched to Esab Dual Shield 7100 Ultra which is the only supplier of 8in rolls of gas shielded in Canada that I could find. Works great, easy to use in all positions. Good penetration cut and etch.
homeboy
  • Posts:
  • Joined:
    Mon Dec 19, 2016 11:52 pm
  • Location:
    Southern Ontario Canada

Louie1961 wrote:
045 diameter at 300A will burn in real well (it won't go into spray-like transfer below about 240-250A)
I have never needed 300 amps for 045 wire (Lincoln 71M). At least on my MM252, I was always in the 220-240 amp range (26 volts, 300-350 ipm) and it worked wonderfully. Nice quiet arc, with no sputtering. What brand of wire do you use Oscar?
The only time I used .045 gas shielded fc, normaly use .035, was welding spring hangers on a flipped over tandom trailer. By memory I think I was a volt or so lower, enough that the vertical weld didn't sag. It is hot! When I tested it on some 3/16 flat at about Louie's setting, 26V, 300ipm it blew right thru! When Blue Demon discontinued the small rolls I switched to Esab Dual Shield 7100 Ultra which is the only supplier of 8in rolls of gas shielded in Canada that I could find. Works great, easy to use in all positions. Good penetration cut and etch.
Bls repair
  • Posts:
  • Joined:
    Thu Sep 24, 2020 6:22 pm
  • Location:
    Pa

I your using mig it has to be spic and span clean . Mig doesn’t like dirty metal !
User avatar
  • Posts:
  • Joined:
    Thu Dec 26, 2013 12:41 am
  • Location:
    Laredo, Tx

Bls repair wrote:I your using mig it has to be spic and span clean . Mig doesn’t like dirty metal !
Some wires tolerate it better than others. That is what deoxidizers and alloying elements (to a certain degree) are for. TIG must be spic and span clean. MIG is middle-of-the-road, generally speaking, and IMO


BASIC WELDING FILLER METAL TECHNOLOGY - A Correspondence Course - Section 6.5
Image
User avatar
  • Posts:
  • Joined:
    Fri Apr 01, 2011 10:59 pm
  • Location:
    Australia; Victoria

S6 works better on mill scale and light grime. S4 do not like anything like that. I used S4 on newly shot blasted steel.
tweake
  • Posts:
  • Joined:
    Mon Dec 18, 2017 4:53 am
  • Location:
    New Zealand

Louie1961 wrote:None of the above. I would use gas shielded flux core in the MIG machine. It gives all of the benefits of 7018, while being infinitely easier to run vertically or horizontally. Much hotter than standard hardwire MIG as well. If you need to stack in multiple passes, its no problem. If you have a smaller MIG, use 035 wire. In a larger MIG use 045 or thicker. Jody has a number of excellent videos of doing structural and pipe welding with 035 gas shielded flux core (aka "dual shield flux core") using the Lincoln 210MP

I have used the Lincoln 71M wire in 035 and 045. I really like it. Others have had good luck with Esab dual shield wires.
thats fine if your in shop with it all ready set up and use it on other things.
but on a farm thats unlikely. hes going to have to buy a rather expensive roll of wire thats probably going to sit around for 20 years.
even then by the time hes dialled it in he could have welded with stick.

mig is great for production in a shop or job site, but for fixing stuff on the farm stick still does the job.
tweak it until it breaks
User avatar
  • Posts:
  • Joined:
    Fri Apr 01, 2011 10:59 pm
  • Location:
    Australia; Victoria

Agree
User avatar
  • Posts:
  • Joined:
    Wed Jan 22, 2014 12:00 am
  • Location:
    Connecticut

thats fine if your in shop with it all ready set up and use it on other things.
but on a farm thats unlikely. hes going to have to buy a rather expensive roll of wire thats probably going to sit around for 20 years.
even then by the time hes dialled it in he could have welded with stick.
We'll have to agree to disagree. Lincoln 71M in 25 lb spools goes for $3.50/lb vs $3.07 for 25 lbs of Lincoln Excalibur 1/8 7018 rods. To me that difference is not very significant. And I believe once he uses it, he will like it and use it a lot more. Its just so much more productive. But different strokes for different folks as they say.
Multimatic 255
cj737
  • Posts:
  • Joined:
    Thu Sep 29, 2016 8:59 am

Louie1961 wrote:
thats fine if your in shop with it all ready set up and use it on other things.
but on a farm thats unlikely. hes going to have to buy a rather expensive roll of wire thats probably going to sit around for 20 years.
even then by the time hes dialled it in he could have welded with stick.
We'll have to agree to disagree. Lincoln 71M in 25 lb spools goes for $3.50/lb vs $3.07 for 25 lbs of Lincoln Excalibur 1/8 7018 rods. To me that difference is not very significant. And I believe once he uses it, he will like it and use it a lot more. Its just so much more productive. But different strokes for different folks as they say.
That's assuming the OP buys a 25# box of 7018 rods. Most hobbyists buy much smaller lots, spending far less. When you have to buy "spools", they can be financially efficient, but the material tends to lay around for years unless you weld regularly.
User avatar
  • Posts:
  • Joined:
    Thu Dec 26, 2013 12:41 am
  • Location:
    Laredo, Tx

weldin mike 27 wrote:S6 works better on mill scale and light grime. S4 do not like anything like that. I used S4 on newly shot blasted steel.
S2 has even more deoxidizers S6 has higher silicon/manganese, but no aluminum/titanium/zirconium like S2. But S2 costs a lot more.

https://www.esabna.com/euweb/mig_handbook/592mig5_2.htm
Image
User avatar
  • Posts:
  • Joined:
    Wed Jan 22, 2014 12:00 am
  • Location:
    Connecticut

That's assuming the OP buys a 25# box of 7018 rods. Most hobbyists buy much smaller lots, spending far less. When you have to buy "spools", they can be financially efficient, but the material tends to lay around for years unless you weld regularly.
That's correct, but it doesn't make much difference. He could also buy a 10lb roll of wire if needed. Again the price is going to be pretty close: $46 for the wire, $34 for the 10 lb can of sticks. But more importantly, why are you so eager to prove me wrong? As I said, different strokes for different folks. I never claimed to have the best answer, just the answer I favor. Why can't you just let it be and respect that I have a different opinion than you do?
Multimatic 255
cj737
  • Posts:
  • Joined:
    Thu Sep 29, 2016 8:59 am

Louie1961 wrote:
That's assuming the OP buys a 25# box of 7018 rods. Most hobbyists buy much smaller lots, spending far less. When you have to buy "spools", they can be financially efficient, but the material tends to lay around for years unless you weld regularly.
That's correct, but it doesn't make much difference. He could also buy a 10lb roll of wire if needed. Again the price is going to be pretty close: $46 for the wire, $34 for the 10 lb can of sticks. But more importantly, why are you so eager to prove me wrong? As I said, different strokes for different folks. I never claimed to have the best answer, just the answer I favor. Why can't you just let it be and respect that I have a different opinion than you do?
I am not trying to prove you wrong. I was merely pointing a consideration as to whether buying spools of wire is as practical as a 1-5# can of Stick rods. I care not which process the OP chooses, and Stick, FC, Dual Shield are all viable choices if he has the material. He never mentioned DSFC as available to him, hence I did not mention it to him.

All good?
User avatar
  • Posts:
  • Joined:
    Thu Dec 01, 2016 12:30 pm
  • Location:
    FL

You guys gave me all this advice, and then I chickened out and used 0.30" MIG.

I have an explanation, though. I had problems with my plasma cutter, and then I found my new propane cutting tips were the wrong size. I had to cut the steel with a dry saw, and by the time I was done with that, I was in no mood to switch spools or put rods in the oven.

It came out very well, though. Should do the job.
I was socially distant when social distancing wasn't cool.
User avatar
  • Posts:
  • Joined:
    Fri Apr 01, 2011 10:59 pm
  • Location:
    Australia; Victoria

What size weld did you end up achieving? The biggest problem you can find with small diameter mig wire is that if you try to push the weld size too much, you can lay too much cold metal into the joint, and have lack of fusion. But if your job is OK, that's the proof.
tweake
  • Posts:
  • Joined:
    Mon Dec 18, 2017 4:53 am
  • Location:
    New Zealand

Louie1961 wrote:
thats fine if your in shop with it all ready set up and use it on other things.
but on a farm thats unlikely. hes going to have to buy a rather expensive roll of wire thats probably going to sit around for 20 years.
even then by the time hes dialled it in he could have welded with stick.
We'll have to agree to disagree. Lincoln 71M in 25 lb spools goes for $3.50/lb vs $3.07 for 25 lbs of Lincoln Excalibur 1/8 7018 rods. To me that difference is not very significant. And I believe once he uses it, he will like it and use it a lot more. Its just so much more productive. But different strokes for different folks as they say.
for a production workshop i would agree.
however you have to factor in the type of use which in this case if farm/repair which is a different ball game.
i can buy sub $50nz packet 7018 but the cheapest dual shield is $150nz.
tweak it until it breaks
Post Reply