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When should i reverse polarity? DC+ to DC-

Posted: Sat May 05, 2018 9:09 pm
by Stato
So i was reading the instructions on my new little Inverter stick welder/TIG... and it suggests that you can reverse polarity if you are welding thinner material. (from my understanding typically you dont stick weld below 1/8th thick.. 3.16mm)

Currently i am welding 2mm Corten sheet to 16mm round black bar on the vertical (right in the gap)

ITs going reasonably well, i have machine set to about 90amps.. i had it on 70 it was going, but felt better at 90, although more risk of blow out.. so far I have only had 2 blow outs one on the old transformer machine set to 100amp and the second on the new Inverter machine...which i felt was odd... with over 60+ weld points....... not sure what happened.. felt random, may have left it too long or not concentrating... not major issues though for the project... Corten Garden edging.

But, should i reverse the polarity?? Would this help? When else should i reverse polarity?

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 05, 2018 10:37 pm
by tweake
Stato wrote:So i was reading the instructions on my new little Inverter stick welder/TIG... and it suggests that you can reverse polarity if you are welding thinner material. (from my understanding typically you dont stick weld below 1/8th thick.. 3.16mm)

Currently i am welding 2mm Corten sheet to 16mm round black bar on the vertical (right in the gap)

ITs going reasonably well, i have machine set to about 90amps.. i had it on 70 it was going, but felt better at 90, although more risk of blow out.. so far I have only had 2 blow outs one on the old transformer machine set to 100amp and the second on the new Inverter machine...which i felt was odd... with over 60+ weld points....... not sure what happened.. felt random, may have left it too long or not concentrating... not major issues though for the project... Corten Garden edging.

But, should i reverse the polarity?? Would this help? When else should i reverse polarity?
depends on the electrode. i assume your stick welding not tig.
you can stick weld car body panels if you want. thickness limits are more about what the lowest setting on the machine is and size of rod you have.
some rods are positive electrode, some are negative. typically the settings are listed on the pack.
i have a few that even list it as positive electrode but recommend negative electrode for root joints. not to sure why that is.

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon May 14, 2018 4:54 pm
by Lightning
Since most stick welding is already done with so-called "reverse polarity" (DC electrode positive), I suspect you're gonna confuse yourself -- and definitely a lot of us -- if you talk about "reversing polarity" on reverse polarity.

Probably save everybody some confusion and grief simply by sticking to the convention of referring to everything as either DCEP or DCEN (or AC).

To answer your question, yes, you might use DCEN for stick welding thinner materials, as DCEN normally gives less penetration than DCEP. And AC would probably fall somewhere in the middle in terms of penetration. But not all electrodes will work right with DCEN and/or AC, so check that first...

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 26, 2018 9:21 pm
by Mike Westbrook
To dumb it down alot to my level at least I imagine on stick that dcep has 2/3 of the heat on the work runs slow and deep and dcen has 2/3 the heat on the rod runs fast and on the surface to keep myself straight I remember positive penetration ........... and negative penetration meaning just that ............so basically try them both see what yeilds the results you want since it's decorative do what's easiest

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Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 26, 2018 9:31 pm
by tweake
Mike Westbrook wrote:To dumb it down alot to my level at least I imagine on stick that dcep has 2/3 of the heat on the work runs slow and deep and dcen has 2/3 the heat on the rod runs fast and on the surface to keep myself straight I remember positive penetration ........... and negative penetration meaning just that ............so basically try them both see what yeilds the results you want since it's decorative do what's easiest

Sent from my XT1254 using Tapatalk
i think some of thats backwards.
DCEN puts the heat into the work. DCEP puts the heat into the rod. eg tig is dcen and if you run dcep you melt your tungsten.
however with stick welding DCEP melts the rod and the molten metal deposits on the work making a bigger hot pool of metal.
a big pool of hot liquid metal is key here, the pool holds heat and that heat penetrates.

as always i'm open for correction

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 26, 2018 9:36 pm
by Mike Westbrook
Could be I got pretty good sunburn on my head today and there's a campfire

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Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 26, 2018 11:15 pm
by MinnesotaDave
Since it's well established that DC- for tig welding has the most penetration, the confusion often is why doesn't stick follow the same rule?

Here is an excerpt from Modern Welding that I use a lot.
It explains why DC+ has deeper penetration (depth of fusion) for stick welding.

"...there is a jet action and/or expansion of gases in the arc at the electrode tip. This expansion causes the molten metal to be propelled with great speed across the arc. The molten metal impacts the base metal with greater force. This heavy impact on the base metal helps to produce deep, penetrating welds." Modern Welding 1997 Althouse, Turnquist, Bowditch, and Bowditch.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat May 26, 2018 11:52 pm
by Poland308
MinnesotaDave wrote:Since it's well established that DC- for tig welding has the most penetration, the confusion often is why doesn't stick follow the same rule?

Here is an excerpt from Modern Welding that I use a lot.
It explains why DC+ has deeper penetration (depth of fusion) for stick welding.

"...there is a jet action and/or expansion of gases in the arc at the electrode tip. This expansion causes the molten metal to be propelled with great speed across the arc. The molten metal impacts the base metal with greater force. This heavy impact on the base metal helps to produce deep, penetrating welds." Modern Welding 1997 Althouse, Turnquist, Bowditch, and Bowditch.
That’s my experience as well. I’ve used dcen a few times stick welding but it usually involves some rusted / corroded through metal of an excessive gap. IE plus 1/2 inch.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun May 27, 2018 7:53 am
by Mike Westbrook
I used dcen alot on my shop it's made of galvalum that's 16 gauge galvanized steel that's aluminum coated so when I made my door frames outside I tacked them with 1/16 6013 at I think 30 amps on dcen due to the frames being heavier gauge than the building it was just what worked best like Poland 308 said it can be useful to build up some big gap on junk farm equipment also

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Re: When should i reverse polarity? DC+ to DC-

Posted: Fri Aug 24, 2018 8:29 pm
by WeldingJunkie
it all depends on what stick you are using and what you welding. I'm not sure why people are saying its for penetration? i mean that's part of it but 7018 and 6010 run in only DCEP. unless you are welding in position then it doesn't matter. you cant run uphill or out of position if you are running DCEN

6011 runs on AC and direct current electrode positive (DCEP), while 6010 runs only on DCEP. This gives 6011 an advantage if you have an AC-only machine. ... These two electrodes have enough strength to do the job and are much faster than 7018

I think [people who don't stick weld are giving bad advice.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat Aug 25, 2018 5:50 pm
by tweake
WeldingJunkie wrote:it all depends on what stick you are using and what you welding. I'm not sure why people are saying its for penetration? i mean that's part of it but 7018 and 6010 run in only DCEP. unless you are welding in position then it doesn't matter. you cant run uphill or out of position if you are running DCEN

6011 runs on AC and direct current electrode positive (DCEP), while 6010 runs only on DCEP. This gives 6011 an advantage if you have an AC-only machine. ... These two electrodes have enough strength to do the job and are much faster than 7018

I think [people who don't stick weld are giving bad advice.
thats a little rough :shock:

as a lot of people tig, especially as most arc welders will do tig, it can get confusing.
but MinnesotaDave's post puts it perfectly.

however as there is very few dc- rods its not a big deal.
penetration with stick is more about what rod you run.

the thing i don't like is people using rods not in the way the manufacture intended they be used for. eg running a dc+ only rod in dc-. usually because the person doesn't want to go get the correct rod for the job.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sat Aug 25, 2018 6:04 pm
by Demented
WeldingJunkie wrote:i mean that's part of it but 7018 and 6010 run in only DCEP.
Um, what?

I've run it DCEP, DCEN, and AC. Lincoln alone makes 4 or 5 different styles of 7018 for various polarities and such.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 5:56 pm
by WeldingJunkie
You got that right Tweake ! buy the correct rod and run it in the correct polarity and you never have to worry. I wasn't trying to come off rough that wasn't my intention but bad advice could give people bad habits forever. You are spot on that just because they can run a DC+ rod in DC- they think its ok.



Demented his post was about DC not about AC roods. I think you will find a lot of people do not know the difference between straight/reverse and dcen/dcep. No one is saying you cant run it with any polarity you want, that doesn't make it correct.

You should post the 5 different rods for running 6010/7018 in DCEN, i think we would all like to know what they are.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 6:36 pm
by Demented
WeldingJunkie wrote:You got that right Tweake ! buy the correct rod and run it in the correct polarity and you never have to worry. I wasn't trying to come off rough that wasn't my intention but bad advice could give people bad habits forever. You are spot on that just because they can run a DC+ rod in DC- they think its ok.



Demented his post was about DC not about AC roods. I think you will find a lot of people do not know the difference between straight/reverse and dcen/dcep. No one is saying you cant run it with any polarity you want, that doesn't make it correct.

You should post the 5 different rods for running 6010/7018 in DCEN, i think we would all like to know what they are.
Unless AWS classifications have changed, XXX8 means AC, DC+, and DC-. Sure, it runs smoother in DC+, but that doesn't mean it's only for DC+. Just the recommended polarity, not THE polarity. Always is worth reading the little booklets that come with electrode packs. There's always little differences in the rods that make them better or worse at certain jobs.
https://www.lincolnelectric.com/en-us/c ... rodes.aspx

For the 6010, never said that runs anything other than DC+. That's what 6011 is for, which also runs AC, DC+, and DC-.


Edit: Here's a breakdown of the 4th digit and it's meaning. https://www.lincolnelectric.com/en-us/s ... etail.aspx

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 8:15 pm
by MinnesotaDave
WeldingJunkie wrote:it all depends on what stick you are using and what you welding. I'm not sure why people are saying its for penetration? i mean that's part of it but 7018 and 6010 run in only DCEP. unless you are welding in position then it doesn't matter. you cant run uphill or out of position if you are running DCEN

6011 runs on AC and direct current electrode positive (DCEP), while 6010 runs only on DCEP. This gives 6011 an advantage if you have an AC-only machine. ... These two electrodes have enough strength to do the job and are much faster than 7018

I think [people who don't stick weld are giving bad advice.
In general, for a rod where AC, DC+ and DC- is an option, DC+ has most penetration, DC- has least, AC is in the middle. Miller even notes it in their stick amp calculator.

Many rods have a "preferred polarity" and then others that also work fine.

You are incorrect when you state "you can't run uphill... DCEN."

Check out this 6G open root pipe weld, 7018, DCEN: https://m.youtube.com/watch?v=RGxIs2a0rR8

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 9:57 pm
by WeldingJunkie
Thanks Dave- maybe i shouldn't of used the words "cant" i should of wrote "shouldn't" anything can be done. I stand by my post with many years of stick welding dating back to 1990. You can run anything you want on DCEN doesn't mean its correct. I'm don't want to get into a pissing match but a simple google search should verify.

With all the respect to you i get what you are saying though. I know you have a lot of experience but stick is my jam.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 10:49 pm
by Demented
WeldingJunkie wrote:Thanks Dave- maybe i shouldn't of used the words "cant" i should of wrote "shouldn't" anything can be done. I stand by my post with many years of stick welding dating back to 1990. You can run anything you want on DCEN doesn't mean its correct. I'm don't want to get into a pissing match but a simple google search should verify.

With all the respect to you i get what you are saying though. I know you have a lot of experience but stick is my jam.
Ok. Why is it incorrect? Why shouldn't DCEN be used?

Simple google searches say a different story than what you are, so please, enlighten us. You clearly know more than we do.

Re: When should i reverse polarity? DC+ to DC-

Posted: Sun Aug 26, 2018 11:20 pm
by MinnesotaDave
WeldingJunkie wrote:Thanks Dave- maybe i shouldn't of used the words "cant" i should of wrote "shouldn't" anything can be done. I stand by my post with many years of stick welding dating back to 1990. You can run anything you want on DCEN doesn't mean its correct. I'm don't want to get into a pissing match but a simple google search should verify.

With all the respect to you i get what you are saying though. I know you have a lot of experience but stick is my jam.
It's all cool man - we're just having a discussion :)

I would say though that I posted counterpoint with example - it's your turn :D

Keep in mind that just because the USA may not do it the same as Sweden or Norway, doesn't mean it's wrong for them to do it. Heck, one welder does pipe work with 6013 overseas :D

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 1:39 am
by tweake
well heres an example.
i have some 6011, AC DC+. i have tried running it as DC- and its horrible even if you can keep it lit. your going to have a tough time doing a good job with that, when you can go get another brand that runs perfectly fine on DC-.
theres a very good reason they don't list it as a DC- rod.

talking about 6013 pipe welding, i see there is a 6013 rod made specifically for pipe welding.
i think you have to keep in mind the specs are very wide, so there is a quite a variety of rods within one spec.

fairly easy to see the advantage of say using 7018 in dc- for root, it means they don't have to carry different rods. much easier and cheaper to stock one rod and make the welder work out how to do it.

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 2:49 pm
by WeldingJunkie
Tweake is spot on, you'll never get the correct penetration. You're right we do have diff codes here in the USA but im talking about running the rod so you get the correct penetration and bead appearance, The rod doesn't care what country its in....

DCEN is absolute terrible for 6010 & 7018 looks like as Jody says Fido's Butt.

Unless someone is going to go out an buy a specialty rod for 6010 in DCEN then i wouldn't use it in that polarity, but this wasn't the premise of the post.


Also im not talking about 6011 nor 6013 those are completely different animals. lastly 6010 is a hard facing rod you don't want to be running it in DCEN for any job that will be specked out or x-rayed.

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 4:24 pm
by Demented
WeldingJunkie wrote:Tweake is spot on, you'll never get the correct penetration. You're right we do have diff codes here in the USA but im talking about running the rod so you get the correct penetration and bead appearance, The rod doesn't care what country its in....

DCEN is absolute terrible for 6010 & 7018 looks like as Jody says Fido's Butt.

Unless someone is going to go out an buy a specialty rod for 6010 in DCEN then i wouldn't use it in that polarity, but this wasn't the premise of the post.


Also im not talking about 6011 nor 6013 those are completely different animals. lastly 6010 is a hard facing rod you don't want to be running it in DCEN for any job that will be specked out or x-rayed.
If proper penetration came down to just running the correct polarity, there wouldn't be so many issues of lack of penetration.

DCEN 6010 should never be done, it's not meant for it. 7018, you still can.

Here's an example for you.
A few weeks ago I had to do a repair job at a local gas plant. Was told everything was SCH-40, so I only brought 1/8 7018 to the job. Turns out one of the items I needed to repair was .065. Rather than fighting running too low of amperage on the 1/8 rod, or leaving to go get smaller, I ran the same amps I usually would, same DIG settings, but flipped it from DC+ to DC-. Still got proper penetration, weld didn't look horrible, and according to AWS and Lincoln, I was within the design limits of 7018.

10+ years ago I'd do the same 7018 DC- on thinner gauge material and root passes. Mostly on root passes because I hate how cellulose rods weld. Have had multiple bend and x-ray tests passed that way too.

There are many other instances where DC- on 7018 or 6011 are beneficial. If 7018 and 6011 rod were never intended to be used in DC-, they'd be XXX0, XXX3, XXX5, XXX6 series rods.

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 4:48 pm
by WeldingJunkie
We keep going back to the same thing. ill agree do disagree at this point....Yes you can do it, doesn't mean its correct?.

lets now change the post to the correct definition "Electrode Negative is straight polarity and Electrode Positive is reverse polarity" just so the OP knows. Since his title was when should i reverse polarity. DCEP is already reversed......

Here my take on this . I feel like we keep saying the same thing in circles so unless hes welding sheet metal there is no reason to run in straight polarity.

7018 DCEP current can make it easier to control the arc and gain a more appealing weld bead because the direction of the current flow is constant. You can run it in DCEN but again that's not made for penetration and in fact 7018 in DCEN is really for thin sheet metal.

This is from Lincoln's Book:
B. Determine polarity by the metallic electrode (E6010) High Cellulose have to be run is DC+ (Reverse Polarity)

1. Clean base metal and position flat
2. Set amperage at 130 to 145 for 5/32" electrode
3. Adjust to either polarity
4. Strike an arc. Hold normal arc length and standard electrode angle and run a bead
5. Listen to the sound of the arc. Correct polarity, with normal arc length and amperage, will produce a regular "crackling" sound. Incorrect polarity, with normal
length and amperage setting will produce irregular "crackling" and "popping" with an unstable arc
6. See above for characteristics of arc and bead when using metallic electrode on correct and incorrect polarity
7. Adjust to the other polarity and run another bead
8. Clean beads and examine. With the wrong polarity, the electrode negative, you will get many of the bad bead characteristics shown in Lesson 1.6
9. Repeat several times, until you can quickly recognize correct polarity

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 5:12 pm
by Demented
WeldingJunkie wrote:We keep going back to the same thing. ill agree do disagree at this point....Yes you can do it, doesn't mean its correct?.

lets now change the post to the correct definition "Electrode Negative is straight polarity and Electrode Positive is reverse polarity" just so the OP knows. Since his title was when should i reverse polarity. DCEP is already reversed......

Here my take on this . I feel like we keep saying the same thing in circles so unless hes welding sheet metal there is no reason to run in straight polarity.

7018 DCEP current can make it easier to control the arc and gain a more appealing weld bead because the direction of the current flow is constant. You can run it in DCEN but again that's not made for penetration and in fact 7018 in DCEN is really for thin sheet metal.

This is from Lincoln's Book:
B. Determine polarity by the metallic electrode (E6010) High Cellulose have to be run is DC+ (Reverse Polarity)

1. Clean base metal and position flat
2. Set amperage at 130 to 145 for 5/32" electrode
3. Adjust to either polarity
4. Strike an arc. Hold normal arc length and standard electrode angle and run a bead
5. Listen to the sound of the arc. Correct polarity, with normal arc length and amperage, will produce a regular "crackling" sound. Incorrect polarity, with normal
length and amperage setting will produce irregular "crackling" and "popping" with an unstable arc
6. See above for characteristics of arc and bead when using metallic electrode on correct and incorrect polarity
7. Adjust to the other polarity and run another bead
8. Clean beads and examine. With the wrong polarity, the electrode negative, you will get many of the bad bead characteristics shown in Lesson 1.6
9. Repeat several times, until you can quickly recognize correct polarity
You're correct in stating DCEN is not made for penetration.

My issue was with you stating 7018 cannot run in DCEN, and is incorrect to run in DCEN. 6010 is the only rod your argument applies to that's been mentioned, but 7018 in DCEN is still CORRECT. It's up to the welder's knowledge to determine which polarity is correct for the proper polarity with a certain rod, weld requirements, and material thickness. Misleading information is misleading information.

It seems like you're applying an argument for 6010 to 7018 as well when in fact they're two massively different rods with massively different characteristics.

Re: When should i reverse polarity? DC+ to DC-

Posted: Mon Aug 27, 2018 7:19 pm
by Poland308

Re: When should i reverse polarity? DC+ to DC-

Posted: Tue Aug 28, 2018 3:16 am
by tweake
Demented wrote:
There are many other instances where DC- on 7018 or 6011 are beneficial. If 7018 and 6011 rod were never intended to be used in DC-, they'd be XXX0, XXX3, XXX5, XXX6 series rods.
well thats not true.
the label is determined by the rods chemical specs, not what polarity it runs.
and the point i made before with the DC+ only 6011 is that the guidelines are very very generalized.
eg there is probably a manufacture somewhere that makes a 6010 that is DC-.
manufactures change the chemical composition of the rods so it can do different things, even tho it falls under the same "spec".

to me if the manufacture specs the rod for it then you can use it.