what type of welding?

I have the feeling we've been over this before but I couldn't find it in the archives, so I'm going to bring it up. Why is stick welding stronger than wire feed (MIG, F/C, or dual shield)? It doesn't seem like it could be because of the quality of the steel of the electrodes. If you were using the best ER70S-6 available, with 100% CO2, what would be inferior about that compared to your favorite brand (Air Liquide, isn't it?) of 7018? I realize that wire feed is subject to cold lap and lack of fusion, but aren't these largely due to operator error? Couldn't you, personally, weld two pieces of bevelled 1" plate together using the setup I described above (or some other electrode if you know of a stronger one---but still in the 70KPSI class) and turn out a weld that was just as strong as if it had been done with 7018? If not, why not? For it to not be as strong seems to defy the basic premise of welding: that if each pass achieves complete fusion with the parent metal or the previous pass, the end result will be the equivalent of a single, unwelded unit (give or take the effects of the HAZ---but it was my understanding that stick is more likely to cause a problematic HAZ than wire feed.)

The code requirement that stick be used rather than MIG or F/C in certain circumstances suggests that stick is stronger, but doesn't prove it. Even if identical results were possible with different processes under ideal conditions, the code could address the real world situation that one process is more likely to result in an unacceptable level of defects.

In short, using equivalent electrodes is stick inherently stronger than wire feed, or is it that the common defects of wire feed just make it turn out that way.

All the best, Stan

"If they all melt the steel so therefore all have the same result, why are there different rods?"

It's my understanding that the differences between various stick electrodes within a given tensile strength classification have more to do with the composition of the flux coating than differences in the composition of the steel. Different manufacturers might use steels of their own special formulation, but I've never read promotional literature by any manufacturer
stating that the steel in their 70xx rods is better than the steel in their 70yy rods. I understand that this is circumstantial evidence, but it's something to be considered.

7014 rods and 7018 rods could be made from the same batch of steel and that wouldn't prevent the 7018 from producing stronger welds than the 7014. Why? Low hydrogen. Low hydrogen is a characteristic obtained from the flux and through the required handling of the 7018.

Why are there different electrodes? Different needs. A person might prefer to use 7018 for every stick welding task but not have a rod oven to hold the rods at the required 250-300 degrees F., not have enough money to open a new package of 7018 for every job (to get around the need for a rod oven), or might have an AC only welder which absolutely won't keep 7018 lit at any amperage the owner can control. But, as you point out, not every welding job is a bridge in Minneapolis, or a heavy duty trailer to haul nuclear warheads. If 7018's characteristics aren't essential to the job, or required, the person might use 7014 because it's AC friendly, or 6013 because it restrikes so well, or 6010 or 6011 because the workpiece is dirty and/or the fitup is poor. That, in my opinion, is why there are different rods.

All the best, Stan

Well, you're right, I'm wrong. I e-mailed Lincoln Electric and got a response within a few hours: "They are a combination of both steel and flux. Certain steels go into certain electrodes as well as the flux." Not only were you right but you write more clearly than that, too.

Keep up the good work, Stan

I’m personally not a big fan of mig / wire feed welding but it has it’s place, and with the cost of labor, don’t fool yourself it’s here to stay. I’m super surprised that on this pipe line project management ever convinced those “old school” pipeliners to use wire feed at all. As a manager myself one of the hardest things I did was convince people to work out of their comfort zone! Getting grown men to change their thinking process is an uphill battle at best!

In my opinion making the statement stick is stronger than wire is a bold statement, and to a degree uninformed, but we are all entitled to our opinions! RIGHT! If you do your research there is a wire on the market that is comparable to just about any stick. One way to look at dual shield, is you have the best of both worlds! Flux, and gas coverage all in the same process. Far as not running wire in a critical situation. That gets down to who wrote the welding procedure, and what engineer approves it. I’ve written hundred of welding procedures, had to make changes to a lot of them, at the request of the engineer of record. It gets down to what information you put in front of the engineer of record, and why. Welding is a huge business, and an ever-changing business. Remember the old saying “there is more than one way to skin a cat”? Same goes with welding ;<)

Don't believe anyone that tells you one is stronger than another - they all melt metal.
Some easier than others and some prettier than others.

Not running hot enough! Not really knowing how to set a machine! Not knowing when to switch from 75 / 25 to 100% CO2!

Now spray arc, is another story ;<)

Now you didn’t really mean that did you?;<)
Ever hear of dual shield, with 100% co2?

so far.. I've "needed" mig welding -0- times to fix my tractor .. but have "needed" stick welding multiple times to fix my tractor.

IE.. if i have to glue 2 3/4" otr 1" plates (back) together... I can either do it with a 250$ 235A stick welder.. or a 2500$ 250a mig... Guess which one is in my garage... the stick!

Soundguy

Vocational school and community college welding programs are often set up so that all types of welding are taught in the same shop at the same time. You might be able to determine if this is the case by looking at the catalog/class schedule. Here, for instance, you would see that half a dozen or more individual courses are offered but that they meet at the same time, in the same place. The instructor has more than enough time to help each student on whatever process he or she is learning.

Unless your local school has way more money than most, they're just not going to have separate facilities for different kinds of welding, so you'll get to at least see, and very likely try, every process during a single quarter, anyway.

In any case, start with oxy/acetylene welding. In my experience, people who don't start with O/A usually won't understand the underlying process of metal fusion as well as those who do, and are often worse operators for it. Besides, no farm or shop can really afford to be without an oxy/fuel setup, mainly for cutting, but also for heating and brazing. (I left out welding because you can't really weld with any fuel except acetylene, and O/A welding may very well not be your eventual process of choice for a number of reasons.)

Proceed, by all means. I firmly believe that learning welding at a public school is one of the last of the really great bargains.

All the best, Stan

$5 a year? It's not THAT much of a bargain for most people. From what you said in a previous post, I thought you were a welding instructor. If you aren't you must teach something else and get a rate that amounts to free for classes you want to take at the school. My wife, the professor, can take classes free at either the local community college or college but she never has the time. I don't pay because I'm sometimes an assistant in the welding program, and usually an assistant in the metal arts program. But when I described public school/college welding programs as a great bargain, I meant at full price---around $125-150 per quarter here.

All the best, Stan

On my last post a meant to send you the link of the tech. school I had told you about.
Here it is: penncotech.com.
Let me know what do you think obout the site.
Guido.

The $5 was all I paid as a resident for 1 year of class. Took 2 for welding back in the 70'S.
A took also 2 years of refrigeration and air conditioning, all at night after work. As I look back it was worth it. I retired from the local Private Tech. school with automotive ,diesel and marine courses and some computer technology was
in the curriculum as well.I was head instuctor when I retired.
Guido.