[Ultralow787]

This whole discussion of polarity versus penetration has perplexed me for some time!

With GTAW, DCEN is supposed to focus 70% of the heat at the work and 30% at the Electrode (Tungsten) for deep penetration. With SMAW, DCEN is supposed to focus 70% of the heat at the electrode and only 30% at the work in order to provide shallow penetration! We use DCEP with SMAW in order to reverse this and place 70% of the heat in the work and 30% at the electrode to provide deeper penetration.

Both arcs come from a constant current power source where current is held relatively constant. The only thing I can see is that something takes place due to the ionization of the Argon shielding gas in GTAW compared to the CO2 that is created from the stick electrode flux?

Any thoughts guys?

[Alexa]

Ultralow787.

During your study of polarities please consider the following as applied to tig.

In tig the heat that melts the base metal and filler (if used) is located at the end of the arc. The intention is to not consume the tungsten electrode. Utilizing DCEN (straight polarity), concentrates heat at the work piece and helps to reduce heat at the tip of the tungsten electrode. Also consider that aluminum melts at 660 C, carbon steel from 1425 to 1540 C, and tungsten at 3400 degrees centigrade. So, with this logic, we could even risk using DCEP (reverse polarity) if the heat needed was minimal, for example in a very thin material where penetration is not desired.

Tanks.
Alexa

[Ultralow787]

Alexa,
I'm good with your description of the tig process, but I'm still looking for clarification on how it is the opposite of SMAW. Any thoughts on this matter?
Thanks

[Alexa]

Ultralow787.

Perhaps the below listed paragraphs by ESAB supplies an adequate explanation for you.

For stick see paragraphs:
2.2.2.3 through 2.2.2.5

For tig see paragraphs:
2.3.2.1 through 2.3.2.5

link:
http://www.esabna.com/EUWeb/AWTC/Lesson2_6.htm

=====

The only thing I would add, is to recall that: - the 'rules of polarity' remain the same for stick and tig; - there is the influence of the electrode coating for stick process; and - there is the choice of changing electrode diameter for the tig.

Tanks.
Alexa

ps: tanks 787

[Ultralow787]

Thanks Alexa, but where do I find these paragraphs you mention? Are they on their web site or a book?
Thanks,
Brian

[Alexa]

Ultralow787.

I added the link.

Alexa

[Ultralow787]

Whew, I thought for a minute there that you were gonna tell me the link had been there all along. Then I would have known I was losing it completely! LOL
Thanks, I'll take a look!

[plantwelder]

Someone made the point about 6013's being more widely used over here (Europe - UK in my case). Granted, I don't do pipe work any more, but in the US you're so anti that I wonder if there is a difference. We used them on 3" - 36" water pipes in the sugar industry with no problems. Here we can get good quality 6013's and there isn't the Farmer's Electrode stigma attached to them. A lot of the work I do I use either ESAB or Murex 6013's, or root with these and cap with BOC 7018's and it always does the job. I use a lot of Murex Zodians with excellent result. I have also used some crap 6013's in the past, generally cheapos, (on the farm) and ended up chipping off more weight of spatter than deposited weld. The Brits on here will remember the old Philips and Filarcs, and shudder.

[echosixmike]

Probably because tight wad amatuers have used cheap garbage 6013 so long that it's stigmatized the product here in the US. But then giving them Excaliber 7018's wouldn't really change anything, probably. Here we generally use MIG where 6013 would apply. Lincoln makes a 6013, as far as I can tell, it's a fine rod. I use it for thin field repair(of mower decks ), as I don't have a suitcase welder and a 115v invertor is a lot easier than hauling an engine drive. S/F....Ken M

[jwmacawful]

i know this is an older thread but just had to put my 2 cents in. especially when i disagree! granted 6013 isn't for everyone and not just anyone can use it to it's full potential. i've used it with great results welding pipe railings. on one of the other welding forums there is a gentleman from ireland who uses 6013 to weld pipe with amazing results. you gotta see the pictures to believe it.

[Otto Nobedder]

I've never had bad results from 6013, and Lincoln does sell one.

I've build tons of boat docks with that rod, and it makes a nice bead, easy to clean. I think the stigma of farmer rod applies in the US, largely because it does not take much skill to do "good enough" on a piece of farm equipment with 6013 and a buzzbox (read that as cheap DIY).

OTOH, most welds that fall under a code in the US will have 6010 in the WPS, possibly for the above reasons. In theory, a 6013 root done properly is as strong as a 6010. That said, I can do the same work with 6010 in half the time of a 6013, in a properly fit joint. (That's a speculation, as I've never tried an open root with 6013, but I've used both rods extensively.)

I think it's about efficiency, but I can't prove it until/unless I try 6013 root (and often enough to do it right), which is unlikely to come up in my immediate future.

Steve S

[AKweldshop]

i know this is an older thread but just had to put my 2 cents in. especially when i disagree! granted 6013 isn't for everyone and not just anyone can use it to it's full potential. i've used it with great results welding pipe railings. on one of the other welding forums there is a gentleman from ireland who uses 6013 to weld pipe with amazing results. you gotta see the pictures to believe it.

Here's the Link from WW. Enjoy
http://weldingweb.com/showthread.php?19 ... pipefitter

[MinnesotaDave]

I noticed some confusion on polarity and penetration.

From the Miller website (SMAW in general):

electrod polarity penetration.JPG (27.7 KiB) Viewed 2965 times

[Antorcha]

The 6013 on AC is the best ornamental welding system out there next to a MIG.If the steel is on the heavier side... 3-5 mm and scaly, it's better than MIG.
One guy mentioned handrails. If you make handrails out of sch 40 and weldable fittings,its a great way to glue them together on site.You can peel it around that pipe and walk away. It's ready for the painter.

Hilco makes 5 different flavors of it for different purposes, likely for that very reason. Ornamental and relatively light sheet. For students it's a "feel good" rod ( look I can weld !) and something to toy with at home with junk steel and toy welders.
With little effort and some hood time on a real machine with 7018 they'll quickly feel right at home with that too.Until uphand:30
If you have a pocket full of 7018 the 6010-11 is nothing more than a tack rod in the real world.Tack they will.Like a 1/4 bolt ! I've tacked sh!t to my table and gone into a rage trying to get it to break off. Sunday matter of fact !

Pipe layers are in Another World. Shut lid. Weld. Repeat. Piss. Repeat. Eat. Repeat.Repeat.Repeat. I hear they even sleep half hanging over the edge of the bead and wear their gloves when brushing their tooth.

Different 6013 rods
http://www.hilco-welding.com/products/product-search
Go click on the AWS dropdown to E6013

[Arizona SA200]

IMHO 6013 is only good for learning to strike the arc at best. My college days they did it with 6011. Ive run both and hate them equally. They have absolutely no place in any industry i have ever been in. Mind you I have only been welding 17 years and that's not a long time for a person in this trade. The rod that is practicable on a job site is 6010 and 7018 as well as there higher yield rods like 8010 9018 and such. As a student learn what the numbers mean and i dont mean just the four number classifications. There can be more numbers for example E7018 H4R a very common rod i use. what does the H4R mean? School will teach you the basics but do some of your own research to advance yourself.

[AKweldshop]

How many of you guys know what H4R stands for?
John

[AKweldshop]

IMHO 6013 is only good for learning to strike the arc at best. My college days they did it with 6011. Ive run both and hate them equally. They have absolutely no place in any industry i have ever been in. Mind you I have only been welding 17 years and that's not a long time for a person in this trade. The rod that is practicable on a job site is 6010 and 7018 as well as there higher yield rods like 8010 9018 and such. As a student learn what the numbers mean and i dont mean just the four number classifications. There can be more numbers for example E7018 H4R a very common rod i use. what does the H4R mean? School will teach you the basics but do some of your own research to advance yourself.

@ Arizona,

Can you argue with the quality of those welds in that WW link???
John

[MinnesotaDave]

IMHO 6013 is only good for learning to strike the arc at best. My college days they did it with 6011. Ive run both and hate them equally. They have absolutely no place in any industry i have ever been in. Mind you I have only been welding 17 years and that's not a long time for a person in this trade. The rod that is practicable on a job site is 6010 and 7018 as well as there higher yield rods like 8010 9018 and such. As a student learn what the numbers mean and i dont mean just the four number classifications. There can be more numbers for example E7018 H4R a very common rod i use. what does the H4R mean? School will teach you the basics but do some of your own research to advance yourself.

For the record, what industry are you in? If it's pipe work, then your statement may be true, but only in the USA since 6013 is one of the main rods in other countries.

6011 is a useful rod the same as 6010 is useful. Not everyone can use DC all the time. For example, machines that have been highly magnetized due to friction can be more easily welded on AC.
6011 rods are used in place of 6010 whenever the extra stabilizers are needed - one example is the maxstar 150s, it runs 6011 better than 6010. One poster on another site reported the maxstar 150 was not designed for 6010 (as told to him by a miller rep).

Don't rule out home hobby welders either, for them many rods are appropriate. I use 7014 quite often, and many home hobby welders like it for the same reasons I do - its super easy to use.
I've only used 7024 a few times, but it was useful for its purpose.

From Lincoln:
"H4R is an optional supplementary designator, as defined in AWS A5.1-91 (Specification for shielded metal arc welding electrodes). Basically, the number after the "H" tells you the hydrogen level and the "R" means it's moisture resistant.

"H4" identifies electrodes meeting the requirements of 4ml average diffusible hydrogen content in 100g of deposited weld metal when tested in the "as-received" condition.

"R" identifies electrodes passing the absorbed moisture test after exposure to an environment of 80ºF(26.7ºC) and 80% relative humidity for a period of not less than 9 hours.

The H4R suffix is basically just additional information printed on the rod, and does not necessarily mean a change in an electrode previously marked E7018."

[AKweldshop]

Dave, do you believe the "R" means that rod is moisture resistant??????

~John

[MinnesotaDave]

Dave, do you believe the "R" means that rod is moisture resistant??????

~John

I only believe what the manufacturer listed that it means. My quote above was a direct cut and paste.

For a period of around 9 hours it can be used after being removed from the oven. Which is longer than rods not labeled that way.

[AKweldshop]

I was asking if you agree with it....

[MinnesotaDave]

I was asking if you agree with it....

I would want to know why I shouldn't believe them?

[AKweldshop]

I was asking if you agree with it....

I would want to know why I shouldn't believe them?

7018 H4r IS NOT moisture resistant, its still should be treated like LoHi, in a 250deg oven.

John

[MinnesotaDave]

I was asking if you agree with it....

I would want to know why I shouldn't believe them?

7018 H4r IS NOT moisture resistant, its still should be treated like LoHi, in a 250deg oven.

John

Yes of course, that's because it is LowHi rod.

Once removed, it can be used up to 9 hours or so without losing the low hydrogen properties.

That's all it means - why would you think I would believe otherwise? I did not post otherwise.

[MinnesotaDave]

Also cut and pasted from lincoln (bold added by me):

Welders accustomed to using a low-hydrogen electrode with a particular classification are sometimes puzzled when they receive electrodes with added designations like "H4R." Low-hydrogen electrodes are generally used in more critical applications to begin with, and their concern is understandable. However, it’s simply a case of the manufacturer providing more information on the same electrode as before.

The added characters are optional designators, permitted by the AWS classification system, to clarify the low-hydrogen characteristics of carbon steel and low alloy steel manual electrodes. Nothing in the electrodes themselves has changed.

Low hydrogen is defined as less than 16 milliliters (ml.) per 100 grams of weld metal. This classification has now been stratified into three levels, so the added designators make it easier to quickly determine how "dry" a particular electrode is. The levels are H16, H8, and H4, corresponding to 16, 8, and 4 ml. per 100 grams of weld metal. These represent the maximum diffusible hydrogen levels obtainable with a specific product.

One additional designator may also be added. This is an optional moisture resistant designator (R), which indicates a low-hydrogen electrode’s ability to meet specific low-moisture pickup limits under controlled humidification tests. This generally indicates that the electrode’s coating has been formulated with non-hygroscopic materials and will resist picking up moisture longer than electrodes with standard low-hydrogen coatings. This can be important when welding in humid areas, since a standard coating will be affected by moisture in about two hours, while a moisture-resistant coating can be safe to use for as long as 10 hours.

When these suffixes are used, they must be imprinted on the electrode itself, in addition to appearing on the label. The actual AWS classification does not change when they are added, however. For example, an E7018 H4R product will still be classified as E7018, although the product is identified by the full designation.

With any low-hydrogen consumable, it is important to observe proper storage procedures. Products such as the H4 electrodes come in a hermetically sealed can. Once opened, they should be stored in a rod oven until used, since they may not meet specifications if left open in high humidity. In case of doubt about low-hydrogen electrodes and their application, the supplier should be consulted for recommendations.