120v MIG 3/8" coupon test results

[aczlan]

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.

Ummm you dont seem to know what you are talking about. What you measure with penetration is the shear or tensile strength of the weld holding the pieces of metal together. If you dont KNOW how well your weld penetrated, you dont know how strong it is.
As for the "penetration" of a bolted joint, if you have 2 pieces of metal bolted together with 2 1/4-20 grade 5 bolts, it takes ~42500# of force to shear both bolts (per the specs at: https://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx ).
To pull the metal apart (ie: tension loading the bolts)it would take ~46000# of force.
For more information than you would ever want to know about designing bolted joints, see: https://www.fastenal.com/content/feds/pdf/Article - Bolted Joint Design.pdf

Aaron Z

 

[MossRoad]

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.

When someone with a bazillion hours of exprience tells you something is possible, but probably shouldn't be done, there's a good chance they are just looking out for your well-being. Stop taking pokes at them every chance you get.

 

[Todd NE WY]

Sodo I have said it before and here it is again, I have built a loader for a garden tractor. This means I have not measured my current one and speculated on what might be able to be done to build it, it means I have been there and done that. I have also said I would not have even dreamed of doing with a 120 v mig welder.

You called me out the last time I commented implying my opinion wasn't credible because I hadn't posted any projects you even implied I might be afraid to post my projects. Well I posted my bale spear build and low and behold, just like I figured you would, you had zero to say.

Your dogged determination to prove the 120 v mig is appropriate for welding thicker metal than the manufacture recommends is getting a little old. I think they have a pretty good idea what their products are capable of.

You go on and on about this being a "hobby, farm, getter done" welding forum of not professions then you say things like with proper prep, etc thicker metals can be welded. Well do you really think the "amateur/getter done" welders have the knowledge or will take the time to do the proper prep work? What this all leads to is at some point an epic fail because somebody read on this forum you can weld 3/8" with a 120 v mig welder, they won't bother to read what they need to do prep wise they will just weld it up and go.

 

[Sodo]

Ummm you dont seem to know what you are talking about. What you measure with penetration is the shear or tensile strength of the weld holding the pieces of metal together. If you dont KNOW how well your weld penetrated, you dont know how strong it is.
As for the "penetration" of a bolted joint, if you have 2 pieces of metal bolted together with 2 1/4-20 grade 5 bolts, it takes ~42500# of force to shear both bolts (per the specs at: https://www.boltdepot.com/fastener-information/materials-and-grades/bolt-grade-chart.aspx ).
To pull the metal apart (ie: tension loading the bolts)it would take ~46000# of force.
For more information than you would ever want to know about designing bolted joints, see: https://www.fastenal.com/content/feds/pdf/Article - Bolted Joint Design.pdf

Aaron Z

Aaron, not sure how you got those numbers but a 1/4-20 bolt is generally good for around 3,500 lbs in shear, or I typically use 4,000. And two of them would be good for (in general) twice that, or 7-8,000 lbs in shear. There are other details, probably more than you ever want to know, but just wanted to clarify your numbers are a ways off. Just FYI, I am a Mechanical Engineer, this subject is well within my skillset. I don't do engineering anymore except I build my own stuff and run some numbers sometimes.

In any case not everybody will understand the similarities between a bolted joint and "zero penetration weld". Zero is not really the correct word, but as long as there was a "shallow puddle" under the entire weld fusion has occurred, that is what I mean by zero penetration weld. Sorry for introducing that comparison.

 

[Sodo]

When someone with a bazillion hours of exprience tells you something is possible, but probably shouldn't be done, there's a good chance they are just looking out for your well-being. Stop taking pokes at them every chance you get.

I guess I should try to figure out what constitutes "pokes". I pretty much have to go on what they wrote, and the part I disagree with becomes my focus. I understand that people can have a bazillion hours experience, but there is a difference between genuine experience, and extrapolating it to a different machine or process. In any case I can see more clearly it's not so much the issue at hand, more the social aspects of a group discussion where it's not clear what the other guy really "knows".

Moss, aren't you even curious why the members who don't have 120v MIGs have such dogged determination to tell the others how they can or can't be used? Why don't you encourage those who have actually HAVE a 120v MIG to go at it, show members what can be done and let's see what happens? Wheres the harm in making test plates?

 

[BlacknTan]

Ohhhh my achin' back .... This is still going on?

The welding forum needs to be nuked, and start over!

 

[Sodo]

Sodo I have said it before and here it is again, I have built a loader for a garden tractor. This means I have not measured my current one and speculated on what might be able to be done to build it, it means I have been there and done that. I have also said I would not have even dreamed of doing with a 120 v mig welder.

Hi Todd, I am curious,,, how much does this garden tractor weigh? (without the loader, just the MFR specified weight). And do you know what is the lifting capacity of your loader? Because when you say garden that sounds easily within the realm of 120v MIG. But if you don't have experience with a 120v MIG I understand.

You called me out the last time I commented implying my opinion wasn't credible because I hadn't posted any projects you even implied I might be afraid to post my projects. Well I posted my bale spear build and low and behold, just like I figured you would, you had zero to say.

Sorry I see so many posts by folks who offer advice without "doing", it was just a reflex I guess, sorry for that. I didn't comment on your bale spear project because I have no bales. Just looked at it today, looks good. The welds I saw appear serviceable I don't think you'll have any trouble with them.

Your dogged determination to prove the 120 v mig is appropriate for welding thicker metal than the manufacture recommends is getting a little old. I think they have a pretty good idea what their products are capable of.

I have an old 1/4" drill motor. It's a Makita. I used "reduced shank" drillbits in it for years. Which means I drilled 3/8" holes, even up to 1/2" holes with my 1/4" drill. Anyway I still have it but don't use it anymore. I now use an 1/2" 18v DeWalt. But I drill much larger holes with holesaws. Anyway same concept. MFR has to provide some number so that buyers can make a decision.

You go on and on about this being a "hobby, farm, getter done" welding forum of not professions then you say things like with proper prep, etc thicker metals can be welded. Well do you really think the "amateur/getter done" welders have the knowledge or will take the time to do the proper prep work? What this all leads to is at some point an epic fail because somebody read on this forum you can weld 3/8" with a 120 v mig welder, they won't bother to read what they need to do prep wise they will just weld it up and go.

I sure hope they take the time to read up how things were done. I think the "weld it up and go folks" are out there doin' exactly that already. The folks who study a forum are probably more likely to take in the assistance offered. It seems many are more than willing to believe that a 120v MIG can only weld sheetmetal. And I suppose others can look at a simple project like this (with 3/16" and 1/4" steel),,,,,,







,,,,,,, and (hopefully) make their own conclusions.

 

[MikePA]

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

I advise that you not feel like you have to respond to every person who disagrees with you. Let the other person's post stand or fall on its own.
(You asked.)

Many, perhaps all, of the threads that have been closed were due to back and forth bickering, each person apparently thinking that just one more post will convince the other person they're wrong. This proceeds for more than a few cycles, with the Moderators hoping one of the participants will recognize the futility of this and simply move one. Sadly, this rarely happens. Add the fact that some people feel the need to reference previous closed threads, usually with an off topic comment like, "I hope this thread doesn't get closed like thread 'x' did.' or 'Thanks for staying on topic.' In other words, they can't let go of previous threads.

Pushing the limits of a 120v MIG welder threads will attract responses from people who feel this is unsafe as certainly as the sun sets in the west. The reader has the smarts to recognize this and can learn from both kinds of posts.

 

[murphy1244]

:laughing:This is like the Red Green show. They can build everything with anything and make it work. Sort of.:ashamed:

 

[zing]

Did this quick today at work

3/8 with 45* bevel
View attachment 391101


Tacked and welded two passes then ground the root and welded one pass to bring it flush
View attachment 391102


Root bent, can see crack developing in area of start, rest of weld looks good
View attachment 391103


No cracks at all in welded area but can see base metal actually starting to rip approx 1/4" above weld
View attachment 391104

Hey FiremanMike, thanks for doing the tests and showing what the 120Vwelder could do. I think it was a good idea you had to do the same with a 220V welder and see what the results are. I have a feeling that there would be a lot of failures from average joe guys on those tests even with 220 V. Maybe not yours, but the average Joe.

Even more though, I am intersted in anything that you may have done to make the weld stronger and better than it might have been if someone less expereinced than you was to weld it. :thumbsup:

Cheers bro.