Mig Vs. Flux core weld break test: Which is stronger on 3/8 steel?
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- čas přidán 22. 07. 2024
- In this episode we weld 3/8th plate fillet welds in order to break them and see what we can learn.
0:00:00 Intro and overview
0:05:24 The test setup
0:08:19 Lets break them
0:11:00 The results
0:16:55 Conclusion
thanks Greg for investigating this. good analysis. I would like to see identical testing on 3/16 inch, or 1/4 inch, as what you did here.
I am going to do 3/8th with all the processes I can do and I will do 1/4in next. I also bought a shop press and will be breaking the welds away from the face as well, to see how things stack up 😀
Love these process tests. Can't wait for the stick and tig.
7018 will be out tomorrow so you won’t be waiting long 😀.
Where's my birthday cake, oh fillet you say, i like the taste of a nice fillet , and welding to, what a great channel Greg
Porosity is always a problem with flux core. I've been using flux cored for 15 years straight now. I found that I get less porosity when I turn the heat up some and the wire speed and my stick out is double. I believe that porosity is from overheating the flux in The Wire. Therefore shorter stick out overheats it.
Thanks Greg ,it's good to know the limits of flux core welds.
It definitely is. I will be going on in the next 2 weeks and doing tests on 1/4in steel (which is more within the realm of what many people work with). I will also be breaking the welds both to and away from the face. 😀
Really liking these tests. Very interesting.
A friend of mine told me he used to work at a factory where he welded on 2-1/2” thick plate steel every day. They used flux core MiG welder. And also used gas shielding with the flux core wire. He tells me welding with double shielded will make the “prettiest” welds you’ll ever see.
Idk I’ve never done that.
So I bought a roll of .035 dual shield for testing. I wont spoil the results (the 3 part video will be out in a week or so) but the welds it produces are flat, perfectly clean, and free of any porosity. They are actually extremely good looking all things considered. .045 and bigger wire is more suitable for thicker plate however .035 will work great on 1/8 to 3/16th thick. Since the molten pool solidifies slow the bead really smooths out nice.
These types of tests, are why you have one of the best channels on YT!
Good comparison on torque measurements; I think you were looking for "relative" vs [not] "absolute" quantities of a breaking strength.
On .035" FCAW...... I've had good weld on thicker plate; but agree that it's always been well above manufacturer specs for V & WFS, to produce a quality weld. While I've used others in the past, for Hobart Fabshield 21B, (& not sure of your amp equivalent) but somewhere around 20.5-22V, & 11-13 m/min WFS. I'm in MO (so usually not metric), but these #'s are from my ArcCaptain, the Miller is even more obscure with it's voltage 1-6 setting and dial for WFS.
Looking forward to more awesome tests & vids- Thanks!
I have a bunch more tests coming out, and I bought a shop press with a pressure gauge to aid in calculating force to compare too 😀. Regarding the flux core, I tried so many things not shown and I always had at a minimum internal porosity. I am going to try to preheat the plates to see if that makes a difference. .035 really isnt meant to weld 3/8th plate. In the near future I will be retesting everything with 1/4in plates to get a more realistic look at what people might do. 3/8th is asking a ton out of most welders people have in the home shop, which is a good place to start since the strength differences will be far more significant.
@@makingmistakeswithgreg - Looking forward to them all!
A preheat will definitely help.
Hi Greg, I have the stars and stripes Miller helmet can I ask what shade you are using for MIG?
Universally I use a shade 11 I believe. I use a Lincoln Viking 3350, and leave it on that. I may drop to a shade 10 when tig welding below 45 amps.
Dual shield flux core would be interesting too.
I have shot 3 videos with .035 dual shield flux core, they will be out within about a week. The results were both good and bad, I won’t spoil it beyond that lol.
Definitely not what I expected!! I’m trying to recall if I ever ran .035 flux, and I don’t think that I have. I think I’ve only ran .045 up to 5/64”. I’ve ran a lot of .035 hard wire and it wasn’t uncommon to run it on 3/8 when I worked in a fab shop. Personally I would have preferred.045 but I just did what I was told. Flux core is nice when it’s dialed in. If my memory is correct tho .035 flux shouldn’t be ran at over 160 amps. I may be mistaken tho. With clean metal and the right settings flux will run pretty damn good, just smoky as hell. Not enough amps and too many amps will both cause porosity. I think if you find the sweet spot in the settings you may get different results if both fillets are the same size. Both wires are rated for 5/16 max I believe, and flux core will have better penetration so I’m kinda scratching my head actually
Outside of the video I ran 3 different wires, different inductance, different settings, and I could not achieve clean welds. It would weld a perfectly clean (surface appearance) welds on the same 3/8th plate just running a bead on plate. Welding a fillet weld on the same plate produces porosity. I ran tig/stick/gas Mig, and even .035 dual shield mig with 0 weld defects on the same plate. To me it seemed like the weld pool is simply cooling too fast and I couldn’t push enough amperage to keep it hot enough. Going low settings and slow, or fast and hot still had weld defects. No doubt frustrating lol. Especially because the same wire produces good welds on everything else 1/4 and thinner. I will have to try preheating the plates to see what happens, that will likely help reduce porosity significantly.
Wut generator you suggest for running a mini stick or flux welder? I think my Lincoln baby flux machine does like 120amps max and same with my stick machine when it’s on 120volt plug, I have a shop sorta in my storage unit where I keep all my lawn stuff and tonight fixing some stuff on my trailer I tripped the breaker in my unit. So I slid down to the next building and used the outside plug and almost got done welding and had it turned down to like 80amps and it tripped that units breaker also 😂. So looks like ima need a decent generator to use for mobile use and at my shop but I don’t wanna get like a damn army diesel style giant unit. I’m thinking prollly like 8-10k watt machine prolly work for my stuff no?
Generator wise a simple rule of thumb is a 120a welder needs about a 30 amp plug or a 3600 running watt 120 generator. If the welder is a higher end one with power factor correction it could be far less. The issue isn’t so much the current draw, but the way the welders load circuits. Basically you end up needing a bigger breaker and generator than what the machine needs simply because of how it loads up the input wiring.
Would a pre heated plate get a better weld seeing that the start of the weld didn't penetrate well but did a bit better has it heated the metal? Also considering the thickness would u want to pre heat? How would a torch set do the old way of welding?
Preheat definitely will help with penetration. I am going to do a break test demonstrating this. It likely will make a single pass weld stronger in this test as well due to the reduced leverage. The only problem with a preheat is controlling temperature. If the preheat is off the performance could greatly suffer. It also could contribute towards more movement in what you’re welding as it cools, which likely isn’t a issue but could be if tolerances must be kept.
I would love to see a similar test with smaller plate. I really have a hard time imagining why/when I would ever need to weld on 3/8. I just finished a frame and mounting brackets with 1/8 angle and that's probably more like what I see myself doing as well as more in the realm of most hobbyists (my guess anyway). I've been doing everything with flux core because that's just where I started. I plan to switch over to MIG at least to learn it. It would be awesome to understand more of the practical tradeoffs.
I will be doing 1/4inch after I get through 3/8th. The purpose of thicker plate is to show more of the limitations of processes and to make the differences far more significant. The hard part with welding on say 1/8th inch and testing, is that all the processes can weld that with 100% penetration and strength, without weld failures. So essentially all of them would have a passing grade, obviously subject to a persons skill level. I will be demonstrating how to get max strength out of welds on 1/8th material though.
Flux core wire is ideally suited for 1/8th material and will be hard to beat on such material. The welds will be a bit more brittle than Mig (as seen in this test video) but that isn’t a real issue on 1/8th material.
would it make sense to use fluxcore for the root and cap it with short-arc mig? I am looking for the easiest technique to create the strongest weld for welding on a semi-trailer. Stick 7018ac for horizontal is not difficult (overhead... I gave up... too hard... I am just using Fluxcore for any overhead)
Flux core wire produces strong welds but on thicker material you have to use bigger (.045+) wire to avoid the internal porosity issues. Most home hobby machines won’t run .045 wire. It is possible to use two different processes for a root and fill, but if you can short arc mig it I would do that because the lack of penetration will likely be made up by cleaner internal welds over flux core. Keep in mind the thickness of what you’re welding matters. The thicker it is the harder it will be to produce strong welds with either short arc or flux core.
Good video. Im about to try welding for the first time. With a 125 flux core welder. Maybe I need something bigger?
A 125 amp flux core machine is good to about 3/16th thick material. At 1/4 you will likely run into porosity issues with the weld (it will still weld it but the welds won’t be as strong as they should be). A 125a flux core machine is a great option for general welding and learning to weld. If you can run good beads with that you can might weld too.
@@makingmistakeswithgreg It's a learning machine for sure. I'll practice a lot.
I have a question. What tech determines the max output of amps on a weld machine? That seems to be the biggest determining factor for prices of machines as the price difference between say a 165 amp and a 200 amp tig welder is pretty big. The 165 amp may even have more features. Anyway great vids!
So there are a lot of issues with making welders for a specific output. To get above 140amps of MiG output (around 100 for stick, 150 for tig) you must have 240v. Making a machine that runs on both 120 and 240 costs more money because of additional components. A 200 amp machine requires beefier components (basically bigger wires, igbt inverters, transformers, etc) that all add to the cost. It’s far easier to take a few components to produce 160amps of output with say 25% duty cycle than a 200amp at 60% duty cycle. Then the issue of keeping all of that cool requires more heat sinks. I should open some welders up and compare them soon 😀.
160 amps output with tig is enough to get a bunch of work done. 160 on stick will be a issue if you need to do bigger jobs where you will hit the duty cycle of the machine, but otherwise will be good. 160 amps with a MiG welder is only going to give the capability of welding around 3/16th steel (1/4 with flux core), so far more limiting. I tell people looking for a welder that they should shoot for 160-180 amps for a stick machine, atleast 160 for tig, and 200 for Mig. That will avoid a lot of pitfalls and limitations. 200 amp across the board isn’t bad either, it’s just that depending on what you’re doing it may not be needed with stick and tig because you can weld thick steel with those processes at lower amperage with good strength.
does pre heat help with thicker material and flux core i kinda like fc because it's so convenient and easy also doesn't smoke the shop out like stick too
Preheat has minimal effect on strength to be honest. I did a video on that a while back but I think it’s worth doing another, so this upcoming weekend I will testing stuff again. Where I think preheat might help with is reducing porosity on flux core welds. When you weld 1/4in and over material internal porosity seems to be very common on fillet welds with .035 self shielded wire. I believe this is a result of how fast the weld cools and how thick the weld is on thicker material. The gas simply can’t escape. I have a feeling preheat would help with this issue.
Many thanks for that investigation! I would have expected the exact opposite. I'm glad i welded my old excavator buckets with max. 160A (due to insufficient welder). Let's say, they work by accident...
I really think the weld size had more to do with being less strong than mig than the weld defects. If I use .045 flux core wire I bet the defects will go away and it will prove to be stronger than those mig welds due to added weld. I will be doing multi pass weld testing and that will help eliminate single bead size differences. Keep in mind too that .035 flux core deposits less metal because its a hollow tube. I tired running more wire speed but the porosity became worse, so the limitations of the thick plate was a detriment to the size wire I think.
I had at least 3 passes each side, weld prepped to 30° and a gap of 2.4mm after rootpass ground out and then welded. Wire 0.8mm selfshielded and steel from 6mm to 20mm. The "ears" 12mm on 20mm I found the toughest. Preheat to approximately 130°C. 6 passes each side. My biggest concern Was the cuttingblades which are hardox 400 (Ar-steel?) but they welded astonishing nice. On one bucket i welded hardfacing rods on the side cutters (that i made of mild steel) and this welding "on the edge😂" was an interresting experience...
AR 400 welds pretty good. The main issue is when you dont preheat it, weld cracks are common. Hardface can be a real animal, I dont know why but I swear every rod runs different and its very difficult to get the heat dialed in perfect. You want to run on the cold side, but with the way it lays down its easy to make a mistake. Then trying to grind the crap off becomes a chore 😂.
Grinder is welders worst and best friend at the same time. 😂😂😂
At about 12:30 minutes into this video you said “if the weld peels off the plate, then you have bigger issues…”
Many times I have heard you say something to the affect of - you want your weld to fail in the filler metal rather than the parent metal…
Could you please explain why a weld tearing away from the parent metal rather than the weld itself failing is an indication of bigger problems.
I recently did a similar test (like in this video) of my welds between 0.035 Solid and Flux Core with the exact same results, which I was expecting based on your demonstration, but two of the welds tore away from the parent metal. This is not the first time I have seen this, and I would like to know why.
Thank You
Something really wrong with that flux core did you keep it heated and dry
So I tried 3 different wires, a broad range of settings (including high inductance) running 1/2in to 1inch stick out, and it still develops internal porosity if not surface porosity. It welds 1/4in and down fine. I talked with a few wire companies (along with looking up spec sheets) and have come to the conclusion .035 self shielded can’t make defect free welds on 3/8th plate. Most companies specify 5/16th max thickness for Gasless flux core, and that’s with bigger wire, not .035.
There is the possibility that it could if the wire feed was far higher than I was running, but I was already outputting 200amps. Even then I believe there would be specs of internal porosity pushing .035 Gasless that hard on thick plate. I am finishing up testing dual shield .035 and that does produce welds completely free of porosity at 180+ amps.
Just for your info, and not regarding this test, you performed, you should try one really good FCAW wire, and that is ESAB Filarc PZ 6138, that have prevalently basic powder filling, but , interesting, works up to 250 amps on DCEN. It is widely used in offshore industry and with
I picked up some other dual shield wires and got some oddball ones to test. Now that I have a 250amp mig welder that I can max out I will get to use some decent wires 😀
I agree weld fillet size was to different to make a sound call here.
In my own exprience dual shield flux core in 035 is good on 3/8 . I would think that dual shield flux core is as good on 3/8 as stick.
7018 etc. If you were going to test 6010 then dual shield 045 would be as good. I believe , correct me if wrong, that the aws on dual shield is the same or similar as stick . The big machine/fab shop across the valley from me uses 1/6 dual shield or stick on the big stuff. dual shield flux core is all postion and easier than stick and faster going uphill. I would be very interested in you doing a dual shield flux core against a similar sized rod, eg 035 vs 3/32 or 045 vs 1/8 stick 7018. I will be doing a repair on a box scraper soon and its 3/8 ribs and I will use the dual shield flux core . I have both 035 and 045 dual shield Esab ultra 7100 , it runs good for me using 75/25.
So I filmed and edited a 3 video series on .035 dual shield (not esab brand) that will be out in about a week. The results I had with the wire I bought have been “interesting” in both good and bad ways. In this particular break test I believe that 6010 will beat out most other single pass processes I am capable of running (can’t do spray arc) because the penetration it has helps it mechanically “cheat” at the test. The 6010 video drops tomorrow, and in it I explain what I mean by that. Basically the test in the video has more to do with leverage than tensile strength, and heavily favors weld size and depth of penetration over anything else.
I will be doing full tests on 3/8th plate on all the processes I am capable of running, then I will switch to 1/4inch plate and re run them. It will be interesting to see what hits the highest numbers. I think it will be tig or 6010 with not a whole lot between them. When I switch to breaking them against the face of the weld the differences will be more interesting I think.
Flux core would as you have shown be not wise on 3/8 plate. It can be done if you chamfer the plate for a larger weld area and do multi-pass process with the correct wire. A GS wire on such thick plate just can't get the job done.
It is normal that flux cored wire that is. Same diameter as solid wire produces smaller fillet weld - and in this particular case you are actually comparing apples and pears. To be accurate, you can machine the fillet weld to same „a“ value , and than brake to compare the values - Apple to Apple.
It’s not quite that simple. Most people’s welders aren’t capable of running bigger flux core wire (such as .045). Universally people either use .035 hardwire mig or .035 self shielded flux core in home shops/garages. The weld size produced can be dialed in equal between the two, despite the flux core putting down less material. The problem is, flux core wire at the .035 size is incapable of producing porosity free welds compared to gas shielded mig, on thicker plate. So ultimately with a 200a welder with gas shielded Mig will produce stronger welds by default, because the internal porosity present with self shielded flux core will weaken the welds with it. The only way to make the comparison “fair” is the use a 250a mig welder, .045 self shielded wire, and compare that to .035 hardwire mig. Which in itself is not a fair comparison because anyone who has a 250a mig welder could easily spray arc weld with .035 wire which will still likely out perform .045 self shielded wire. So believe it or not the comparison shown is as fair as you can make the comparison based on limitations of the wires themselves and the welders people have. The second you lift the equipment limitations to boost flux core you also boost the hardwire. Even dual shield isn’t a viable option on a 200a machine, the .035 dual shield performs poorly on thicker plate, it has no root fusion. It doesn’t have porosity issues though, but it is still beat by hardwire mig.
@@makingmistakeswithgreg well, you are talking about 200-220 Amps welders that are not capable to use 0,045“ dual shield wires. I am situated in Duesseldorf, Germany and possess Weldinger 300 A pro Synergic GMAW machine, and no problems with adding the power when welding fillet welds that are bigger size on thicker steel. In your test, you welded in 2F position that is very limited, I would say, intentionally. What is with 3F? 4F? In those position is, for average welder, to produce sound and geometric correct weld that is not too much concave, is almost impossible, if they not possess pulsed machine - and regarding peak amps value, that are , again, not 200 amps machines…… with Dual Shield 7100 ultra is that - piece of cake in those welding positions. With my garage 300 amps machine I welded in wertical up position , without porosity, with DS wire 0,052“ - 230 ipm - approx 220A - 26V and approx 3/4‘‘ Stickout . I would say that , regarding welds and productivity, all is depending from point of view - the most welds are oversized anyway. And, not to forget, when roasted or painted plates are welded, porosity is greater with GMAW solid wire than with FCAW .
About porosity…..you used Blue Damon FCAW wire 0,035” . I used not only Dual Shield 7100 Ultra (now under ESAB), Lincoln Electric Outershield 71T-1 M ans PZ 6138 in same diameter, and have no inclusions or porosity. It should be investigated what happens with Blue Damon wire ( possible humidity pickup during longer storage time, or just - bad wrapped wire) . For your info, I welded with FCAW wire Dual Shield II 110 in year 1994, so 30 years ago, ASTM A517 gr. Q , in all positions, with no porosity or other issues. As I remember, the wire reels were packed in the can (2 reels in one can), and that is disssadvantage only for - garage welders. Why to avoid humidity is to pack the reel in plastic bag - and vacuum it after use. Today , you can use simple vacuum electric machine everyone use to vacuum the pillows. Also, what is also truth ( we tested that in our Institute) that 27% of porosity in the weld carrying area if porosity is globular type, produces decrease in mechanical properties of only approx 4,73%. And believe me, it is very hard to produce porosity of 27%…. Actually, we intentionally left the wire in very humid basement for a 2 months to produce such a porous weld. Regarding edge fusion, we had also problems at the beginning, we rectified issue with more inductivity, or today with +2 on arc dynamic. Second way is to increase fillet weld size to be sure to proper “a” size that will compensate smaller a size according to same welding parameters comparing with solid wire, with just simple - grinding 1 mm from the edges of the upper plate in fillet weld configuration. And the best wire for fillet welds on clean surfaces is not even mentioned or tested , and that is MCAW wire - metal cored wire in the class ER70S-6. Also , better than solid GMAW wire, regarding edge penetration I applied is Lincoln Electrics NR- 232 , 0,068”.
anyone else find that flux core wire brands make a huge difference in deposition rate? the stuff I buy from SIP seems to put down waaay less metal at the same settings as what I get from Geka and Super6 (I'm in the UK if those brands mean nothing) It'd be nice if you could guarantee you put down the same amount of steel to make the results easier to compare but if the consistency in the wire is all over the place I don't know how you might be able to do that
Thanks Greg, love the content. I have a couple of stick welding side gigs lined up this month, I don't think that could have happened without your stick series.
It is very difficult to put down 100% identical weld sizes because the processes are so different. .035 flux core and .035 MiG wire have completely different deposition rates and they penetrate different. Even though the flux core weld is smaller, it’s extra penetration does add up. I will be doing a full scale test of all common processes on 1/4in plate. For now I am focusing on the extreme end to really see what the limit is with a average machine a person has. I also want to establish some fundamentals and get people to understand why you should look at some welding processes over others. I have had many people tell me stick welding is irrelevant in todays world, yet in a home shop stick is far superior to Mig on thick plate with a 200amp or less machine. It’s best to have/know how to use all processes and use what’s best for the situation.
Also, no problem on sharing stuff 😀. I am excited for you that you have some stick jobs lined up. It was my hope to get people to believe in themselves and share enough information that people had the knowledge/skills to do it. I am glad you learned enough to up your game, and hopefully put some money in your wallet 😀
SMAW VS GTAW for strength next, please
I have a bunch more filmed and rolling out over the next few days 😀.
Self-shielded core wire like any other cellulose covered welding electrodes causes the hydrogen embrittlement and therefore less stronger welding beads.
It can absolutely. I have a few videos coming out showing hydrogen escaping from welds to demonstrate the reality of how easy it is to put hydrogen in a weld. I know certain flux core wires meet low hydrogen specs, but not all. With everything in welding, if someone wants to weld metal thats susceptible to hydrogen embrittlement, they need to take proper precautions to weld it. Or very undesirable results will happen lol.
3/8 is structural and it likely needs 045 or larger wire. 035 might work with a big preheat.
No doubt both are inadequate for that thick of plate. The MiG did better than I expected given 200amp max I had to work with. The flux core would have performed much better with bigger wire for sure. The limits of a 200amp machine will be the deciding factor with in this case for sure
Personally I'd prefer 1/8th inch 7018 stick for anything over 1/4 plate
I tested that and the 2 videos will be out shortly. The first video shows a some 7018s clean and some welds with defects all run at 120 amps, the second video shows all clean welds run at varying amperages. I also tested 6010 😀
17 lb at best not bad at all on a low amp supply thanks
Turn the inductance up to 80 percent
No Stick.....?
I just uploaded a day or two ago a stick test and I have a bunch more coming out in the next week 😀
My guess will be flux will be stiffer but more brittle and full of holes. MiG will bend further with less pressure and snap eventually around the same force... Just my guess. Let's see!!!
The flux core certainly was stiffer. To me bending the flux core felt very hard and then cracked not soon after I felt any movement. Which would definitely coincide with the fact it’s yield and ultimate tensile strength is very close to each other. The welds definitely had porosity, which I can’t eliminate with .035 wire on 3/8th plate no matter what I did (too small of wire and not enough heat). The flux core was a bit below MiG, however it likely had to do more with weld size differences than the porosity I think. Anyway, excellent thoughts and you were spot on 😀
Could be high silica content and your travel speed is to high not giving enough time to burnout the impurities
Maybe heat the piece up to sweat the moisture out of it.
So why even record and post if the welds aren't the same length?
What was the logic of that?
The welds are the same length, so are the pieces of metal? The welds are different physical sizes, which is unavoidable because the processes have different deposition rates. To make them equal in size .045 flux core would need to be used, which isn’t a option for many home use MiG welders. What the flux core lacks in physical weld size is gained in penetration. 3/8th is just beyond what .035 flux core wire can really weld, I don’t believe it’s possible to use that wire and get defect free welds on 3/8. It still had decent break strength all things considered.
Use dual shield next time
I have 3 videos coming out on .035 dual shield next week 😀.
why u didn't opposed side u wrong when u didn't its ok
Or your stickout is to close causing wormholes.