120v MIG 3/8" coupon test results

[firemanmike69]

I was curious to see if Mike welded the same materials with a big setup if things would look different. That could take away the variable of different welder technique.

If I have more time in the upcoming weeks I'll do a proper to d1.1 coupon one with the big welder and one with the mig and we'll see how different or similar they look. In your post you mention having a dedicated circuit in our shop if I plug a9" grinder into the same circuit as the welder And have someone really hog material out with the grinder it's really noticeable in the arc of the little welder, obviously not so much on the big welder

 

[Sodo]

Mike I've never run 1/4" rod, and would like to see it, try it (in person). But that sounds like it may throw a 120v MIG off-topic?

Most people who have 120v MIGs don't share amps with a 9" grinder. (maybe a washing machine though!) They just wanna know ---- for the occasional thicker bracket ---- how to prepare and execute a weld on a thicker piece, if it becomes necessary. Post a question, and get CIVIL WELDING ASSISTANCE on TBN. They don't need to be told to buy a 240v machine then call the electrician to re-wire the garage for 240v -----> for one bracket.

They wanna repair a deck chair or BBQ, weld a muffler, which is near impossible to stick-weld (for an occasional weldOR) but just "easy" to MIG. Which is why they bought into the small "MIG" program. It's a very useful tool.

As mentioned before (cue up broken record), my entire 5-foot bucket on my Kubota 2710 is made of 3/16 with a few 1/4" brackets, and a 3/8" cutting edge. The entire FEL loader arm assembly has nothing thicker than 1/4", even the brackets for the hydraulic cylinders. Aside from the cutting edge, a 120v MIG (a Miller 135, 140, certainly others) could weld this bucket together very nicely, not be over-driven. And arguably, an experienced welder could get the the 3/8" cutting edge to stick "good enough" = "never break".

I suspect member projects are generally much smaller than constructing an entire FEL assembly for a 30hp tractor. A good 120v MIG can be a very useful tool. Some are better than others, IMHO, of course.

Thanks very much for your even-handed approach. If I sound touchy on this subject its because EVERY 120v MIG thread (if it ever gets the attention of an experienced weldOR) goes off in the direction of "How I'd do it with a bigger machine". Of course anybody who has a bigger machine would use it. Understood how this causes a GAP in the 120v MIG assistance, but 120v MIG owner wants help with the machine that he HAS, can't make much use of assistance of tips for a bigger machine.

 

[Arc weld]

When I went to school all the bend tests were on 6" wide plate and we never cut the plates at all. We didn't grind them either. Pipe bend tests are ground flat. It's a little harder when they're ground flat but a sound weld will bend regardless. The idea was to weld from one end to the other and have no flaws period. Sometimes with the 6010 root it was tricky because your rod might not quite make it to the end. Do you try to make it with one rod or stop, feather your weld and use a second rod to finish? When you have a good root going in, you try and make it to the end. If 1/32" under-fill is acceptable, the allowable amount is still only for 1/8". Sometimes you have the option of a bend test or an x-ray on pipe tests. It's always tough to decide which is easier to pass.

 

[firemanmike69]

Sodo: I was trying to underline the importance of not having your shop lites or drill or something else sharing so to say the 15 amp circuit with the welder
Arcweld: I understand your concerns and I have said that I will try to get a test closer to aws d1.1 but for now that was the best I could do with the free time I have thank you for your guidance on how I should be preparing and bending my plates. So I understand correctly I should be doing 2 6" plates and bending the face of one and the root of the other?

 

[Blade Breaker]

Mike I've never run 1/4" rod, and would like to see it, try it (in person). But that sounds like it may throw a 120v MIG off-topic?

Most people who have 120v MIGs don't share amps with a 9" grinder. (maybe a washing machine though!) They just wanna know ---- for the occasional thicker bracket ---- how to prepare and execute a weld on a thicker piece, if it becomes necessary. Post a question, and get CIVIL WELDING ASSISTANCE on TBN. They don't need to be told to buy a 240v machine then call the electrician to re-wire the garage for 240v -----> for one bracket.

They wanna repair a deck chair or BBQ, weld a muffler, which is near impossible to stick-weld (for an occasional weldOR) but just "easy" to MIG. Which is why they bought into the small "MIG" program. It's a very useful tool.

As mentioned before (cue up broken record), my entire 5-foot bucket on my Kubota 2710 is made of 3/16 with a few 1/4" brackets, and a 3/8" cutting edge. The entire FEL loader arm assembly has nothing thicker than 1/4", even the brackets for the hydraulic cylinders. Aside from the cutting edge, a 120v MIG (a Miller 135, 140, certainly others) could weld this bucket together very nicely, not be over-driven. And arguably, an experienced welder could get the the 3/8" cutting edge to stick "good enough" = "never break".

I suspect member projects are generally much smaller than constructing an entire FEL assembly for a 30hp tractor. A good 120v MIG can be a very useful tool. Some are better than others, IMHO, of course.

Thanks very much for your even-handed approach. If I sound touchy on this subject its because EVERY 120v MIG thread (if it ever gets the attention of an experienced weldOR) goes off in the direction of "How I'd do it with a bigger machine". Of course anybody who has a bigger machine would use it. Understood how this causes a GAP in the 120v MIG assistance, but 120v MIG owner wants help with the machine that he HAS, can't make much use of assistance of tips for a bigger machine.

Sounds like the real test you need to prove your statement about welding the bucket is some lap and tee joint welds with your mig. You will find that more current is required for lap and tee joints to get root penetration. To prove this let's see some 1/4 to 1/4 tee joints and bend them. Then some 1/4 to 3/8 lap joints and bend them. It would be great to see some acid etch tests done on these welds.
I would need to see these tests before I would believe a low voltage mig will get er done on anything but sheet metal.

 

[yomax4]

The AWS spec on S6 wire is pretty broad. The wire you test with will surely be a factor in the bend test. Some import wire silicon contents are all over the map. A little pre heat and a quality wire will change this whole test. Take away the pre heat and the wire will still matter.

 

[Sodo]

Sounds like the real test you need to prove your statement about welding the bucket is some lap and tee joint welds with your mig. You will find that more current is required for lap and tee joints to get root penetration. To prove this let's see some 1/4 to 1/4 tee joints and bend them. Then some 1/4 to 3/8 lap joints and bend them. It would be great to see some acid etch tests done on these welds.
I would need to see these tests before I would believe a low voltage mig will get er done on anything but sheet metal.

Blade I understand what you're saying. However on the FEL bucket there are a lot of corners joints welded both sides which (I bet) achieve full root penetration. Or otherwise result in full strength necessary for the application (sometimes referred to as good enough or get er done ) And there are lots of other types of joints which are designed in such a manner that the welds are not able to be stressed like a "test plate". Weld is not allowed to be "in bending".

I understand what a test plate tells you, but I also understand weldment design to avoid bending, never subject it to the stresses that occur in a bend test. Many welds are designed to be in shear (and should be) for that very reason, whether it was done with 120v or 240v or 480volts. (or 575v )

This 3/8" coupon test business that is being pioneered by TBN welding subforum is intended to push a 120v machine to a limit, with a maximum material thickness, then subject this weld to the maximum stresses that can be imagined, a bend test. I understand what this shows about the weld, and there is certainly more detail to learn as the experts slip it out. But these weld assessments are just a small part of weldment design. Nobody should be designing their weldments to put such a weld (done from one side only) in bending. (IMHO).

Or "failing" a weld because it would not survive a root bend test. I see welds every day on production items that would never survive a root bend test, but the weldment design is such that the weld is never stressed in that manner.

Cut 2 plates of 1/4" steel plate, and weld a fillet joint with 120v, no joint prep or grinding. Agreed the penetration will be minimal and I bet it breaks in a root bend test (as you say). Weld 2"x2"x 1/4" Rect sq. tube together in a Tee, and it is firkin' STRONG joint, I don't know how you'd break it but it's going to be strong. Whether this joint is appropriate for the application is dependent on the welder, the weldOR, and perhaps the highest responsibility, upon the "weldment designer".

 

[Blade Breaker]

The AWS spec on S6 wire is pretty broad. The wire you test with will surely be a factor in the bend test. Some import wire silicon contents are all over the map. A little pre heat and a quality wire will change this whole test. Take away the pre heat and the wire will still matter.

Your right about the imported wire. I've seen porosity issues.

 

[Blade Breaker]

I completely agree that every weld does not have to be test plate quality. Your machine should be capable of making these welds at least and a low voltage machine is not refering to the welds mentioned here. It's a fact. Of course some items welded with these machines will stick together due to the design of the part and the loads on it. This does not mean the welds are good or even ok. Your looking to have it proven that these machines are good to use for heavy plate work. This is misleading others that do not have the experience to know the difference and it is bad advice.
Use the manufacturer recommendations when choosing your welding machine. If you need to weld plate on 120v get a stick welder it's cheaper and you can weld out in the wind so your shop stays clean. Your obsession with this topic is impressive and annoying at the same time.

Blade I understand what you're saying. However on the FEL bucket there are a lot of corners joints welded both sides which (I bet) achieve full root penetration. Or otherwise result in full strength necessary for the application (sometimes referred to as good enough or get er done ) And there are lots of other types of joints which are designed in such a manner that the welds are not able to be stressed like a "test plate". Weld is not allowed to be "in bending".

I understand what a test plate tells you, but I also understand weldment design to avoid bending, never subject it to the stresses that occur in a bend test. Many welds are designed to be in shear (and should be) for that very reason, whether it was done with 120v or 240v or 480volts. (or 575v )

This 3/8" coupon test business that is being pioneered by TBN welding subforum is intended to push a 120v machine to a limit, with a maximum material thickness, then subject this weld to the maximum stresses that can be imagined, a bend test. I understand what this shows about the weld, and there is certainly more detail to learn as the experts slip it out. But these weld assessments are just a small part of weldment design. Nobody should be designing their weldments to put such a weld (done from one side only) in bending. (IMHO).

Or "failing" a weld because it would not survive a root bend test. I see welds every day on production items that would never survive a root bend test, but the weldment design is such that the weld is never stressed in that manner.

Cut 2 plates of 1/4" steel plate, and weld a fillet joint with 120v, no joint prep or grinding. Agreed the penetration will be minimal and I bet it breaks in a root bend test (as you say). Weld 2"x2"x 1/4" Rect sq. tube together in a Tee, and it is firkin' STRONG joint, I don't know how you'd break it but it's going to be strong. Whether this joint is appropriate for the application is dependent on the welder, the weldOR, and perhaps the highest responsibility, upon the "weldment designer".

 

[Sodo]

Of course some items welded with these machines will stick together due to the design of the part and the loads on it. This does not mean the welds are good or even ok.

I don't agree with that statement, it's far too broad. Many welds with little root penetration are more than sufficient to support the loads as designed. What is the "penetration" of a bolted joint - Zero, but it can work if designed properly, they are everywhere. Fusion is another aspect of a weld joint that has a large effect on the serviceability of a weld.

Your looking to have it proven that these machines are good to use for heavy plate work. This is misleading others that do not have the experience to know the difference and it is bad advice.

Heavy plate work? Where did you get that? Please re-read this quote, from post #22 (7 posts back) it lays out my intent I think. If it is not understood, please let me know what part is not understood.

They (120v MIG owners) just wanna know ---- for the occasional thicker bracket ---- how to prepare and execute a weld on a thicker piece, if it becomes necessary. Post a question, and get CIVIL WELDING ASSISTANCE on TBN. They don't need to be told to buy a 240v machine then call the electrician to re-wire the garage for 240v -----> for one bracket.

It's not bad advice.

If anything is "BAD",,,,, its that advice how to do it is being withheld from members, slowing their progression in developing the experience. They have projects, want to start developing the experience ASAP.


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Your obsession with this topic is impressive and annoying at the same time.

I submit than "my obsession" is useful to many members on this hobby/maintenance welding forum. And "your obsession" (that a 120v MIG is only for sheetmetal) is not useful info. With regards to your annoyance,,,,,that is 100% your department.
:laughing::laughing::laughing:
It is your choice to participate in topics that have "120v" in the subject line and not my responsibility to create threads appropriate to your experience or interest.

Please don't run this thread down that wormhole and get it closed. Those of us who are interested,,,,,are trying to get something worked out and are trying to attract assistance from members who HAVE the applicable experience (and a willingness to offer it not just say "NO you can't").

Moss Road or MikePA ----> can you offer some advice here before this gets out of hand?