Another welding question

[showcrop]

I got my first welder about 20 years ago but never learned how to use it. I have done quite a lot of fabrication and repair of my equipment and I can make a weld that looks half decent, and nothing I've done in the last 20 years has come apart. I have been using mainly 6011 and 6013, mostly 1/8 inch but sometimes bigger and sometimes smaller. Then the guy that I buy stuff from told me I should be using 7018 so thats what I got. 3/32 diam. My problem is that I have to turn it up higher to strike an arc, then the rod heats up and bends and I can only use half of it. What am I doing wrong?

 

[trucker40]

Its too hot.What kind of a welder do you have?What are you supposed to run the rod at?Every welder is different,but when you get 7018 running at just the right heat the slag will curl off of the weld when you are done.
Just guessing at 3/32 maybe around 70-80 amps,but it might say on the box.
7018 is hard to strike an arc with.You just have to get mean and strike it.There are 7018 AC rods that are easier to strike.
Since you dont know a lot about welding maybe you should try 7014.You can weld with 7014 about the same as 6013,but the weld is better when you get done.Easier to strike an arc with and stronger weld material than 6011 or 6013,not as strong as 7018.
Now people will tell you anything.7018 is the stronger weld,but if you dont do it right and cant strike an arc,you could be just as well off using 6011 or 7014.Im a welder and have problems with 6013.If you weld with 6013 you need to look real close at it to see if its full of slag or not.Its for sheet metal and not a deep penetrating weld.

 

[Stan in Oly, WA]

Hi Showcrop,

What kind of welder to you have? If it's AC only, as many Lincoln tombstone welders are, you need 7018 AC rods (or some other AC friendly type, like 7014.) In an earlier posting, trucker40 stated that it's entirely posible to weld with regular 7018 with an AC welder. I don't dispute that but it's important to keep in mind that he also mentions that he's a weldor and that he burned a couple of 50# cans of 7018 in the process of learning to run them on AC. If you're going to be welding only occasionally and you have no formal training, it's highly unlikely that you will get to the point of being able to use regular 7018 electrodes with an AC welder.

If you are having the problems you describe while you're trying to use 7018 with a DC welder or 7018 AC with an AC welder, then trucker40's advice is the first thing to try.

All the best, Stan

 

[Puddles]

showcrop my first question is, what are you building that requires 7018? I think the general public believes 7018 is a cure all rod. Don’t get me wrong I’ve run tons of 7018, and it is my go to rod. But there is nothing in the world wrong with 6011. The last few years on all of these forums seems as everybody dismisses 6011, so I thought I’d do a little experiment / testing with 6011.
First off I’ am not a pipe weldor, but I can get by. I ran this pipe test in the 5-G position, open root, 6011 start to finish. Now if 6011 can take a bend test like this, why would the average home / farm weldor use anything else?

For what it’s worth I’ am so impressed with ESAB’s Atom Arc 7018, if you have your heart set on running 7018, maybe give some Atom Arc a try!

 

[eastexan]

Ditto's with Trucker & Stan.

Also, sometimes some brands of 7018 are harder to strike than other brands. I found that out with my Miller Bobcat (DC).

I got some 7018's one time that would strike easy the first time, and if I used the whole rod up there was no problem. But if I stopped, it was hard to restrike. I would have to take it out of the holder and rub it against something to clean the crust off the tip of the rod, then I could use it again. Other brands of 7018 weren't quite that finicky.

And it could be your rods are damp. You need to keep 7018's sealed up, until you go to use them.

I agree about using 7018 AC. Even if you have a DC machine, they will strike easier. Get you a fresh pack of 7018 AC, and try them out.

Ronnie

 

[Anonymous-0]

You are better off using 6011.Some old welders cant run 7018.I have an old 150 amp welder that wont run it.When I want to use 7018 I bring out my Lincoln 225.Stainless makes nice welds,I can weld new exhaust pipe with 316, looks like an expert welded it.

 

[eastexan]

Puddles, that impressive. It took me a little while to figure out what you were talking about in those pics.

Most of us here though, aren't professional welders like you, and 6011 takes more skill to run than 7018 does.
I like using 6011 though, because you don't have to worry about dampness. And it penetrates through surface rust and paint, and still gives a strong weld.

Ronnie

 

[old]

7018 was first made for DC welders then they did a little to the flux so it could be run on AC but it is still more of a DC welder rod. For AC 7014 will work better for you and is a bit stronger in some way then the 6011 and is about as easy to use as 6011 is.

 

[Puddles]

Thanks for the compliment Ronnie!
I’ am no longer a professional, just like to play. :lol:
To be honest, I’ll bet the farm I’ve never run a whole box of 6011! :wink:

 

[Ecnerwal]

Remember that the goal is to stick stuff together, not impress people with your prowess, at least for us backyard welders. If you are welding clean and flat, no reason not to go all-out on the cheat scale and use 7024 - doesn't work with a darn in any other position, but you can practically weld blindfolded with it and get bee-u-ti-ful welds.

7018 varies. Using it takes some skill. I was fortunate enough to get some welding classes in during college (having an Ag Eng department on campus is handy even for those not in the Ag Eng program), and 7018 didn't show up until the advanced class. 7018 (even 7018AC) does not work worth crap on welders with a low open circuit voltage - the low end buzz-box type usually can't cut it. I have a fairly nice welder, but with the frequency that I don't weld, it would probably take me a few hours practice at the minimum to get back up to a reasonable degree of running 7018 (or 8018, 9018, 11018...) like I knew what I was doing, even though I did pass the class and that included all-position welding - 16? years ago...

When you need XX18, you need it - that's things like welding high-carbon steel, where you'll get cracks after welding if you do it with XX10 for more than a root pass. That's also where you can run into problems with damp XX18 rod, since it's not low-hydrogen if it's damp. If you are glomming mild steel together, that's not as much of a concern.

If you have a DC welder and want stronger welds, 7010 and 8010 are closely related to 6010, but stronger. 6011 is just AC 6010. BUt even 6011/6013 are considerably stronger (the 60 part) than typical mild steel (36, on the same scale, as I recall?)

I'm pretty sure I don't agree that 6011 is harder to run than 7018. Mostly, it makes an ugly weld, but since it makes an ugly weld that works, I use a fair amount of it (or a 10, since I did get a DC machine), given that much of my welding in recent years is backhoe repairs, and usually there's not time to grind everything to a fair-thee-well so it's all clean and pretty.

ANY sort of rod is a lot easier to run if you grab 5 pounds of it and some scrap metal that approximates the actual job you need to do (in thickness and geometry if at all possible) and PRACTICE before you make the first bead (or 10) you've run in months or years that actually matters. You get an idea of the right settings, you get to remember how your hands are supposed to move, and the thing doesn't matter because it's just practice. Costs a little in rod, saves a lot in screwing up the actual work.

 

[Stan in Oly, WA]

Hi Ronnie,

Having used maybe a dozen different brands of 7018, I'd say that your experience with the 7018 that was hard to restrike is closer to the rule than to the exception. In my experience, 7018 burns back up inside the flux coating so that when you go to restrike it there's no metal to make contact with the work until you get rid of that little tube of flux. I used to use my left thumb (inside a heavy leather glove) to break off the flux until I wore a hole there and then went ahead and tried to do it anyway (twice.) A deep burn right in the center of your thumbprint really gives you something to remember for awhile. I've tried a number of ways to deal with this situation but what works best for me is to keep a piece of steel beside where I'm welding to tap the end of the rod on right before I strike a new arc.

All the best, Stan

 

[Bud in FLA]

Pretty coupons!
My first pipe test was 6" sch 40 open butt in 6G position with a 7018 root pass and weld out. I'd hate to think I had to try that again!
I used to upset our new guys - if they couldn't weld as well left handed as right handed, they weren't welders.

 

[Anonymous-0]

That's not easy to do. I would take 6011 over 6013 or even 7014 any day of the week if I wanted a stronger weld and didn't have 7018 or the machine wouldn't burn it. 7018AC gets porosity some times when used on DC. 6010 and 7018 are the 2 most common rods to have around with maybe some 7024 for higher production. Dave

 

[Bud in FLA]

You're burning too hot. Cold, "damp" 7018s are *bad* about sticking - hard! You can twist a 6010 loose but it takes a chipping hammer or a grinder and a abundant application of "mechanical terminology" to get a 7018 loose.
Hot, dry 7018s aren't a whole lot better! It takes practice. Once you get the hang of 7018s they're great but the learning curve is not fun.

 

[Anonymous-0]

Just for kicks, you should see if 6013 will bend like that. At 650 deg., I think, we put 6010 plate coupons in the bender. They would break showing the grain structure of the weld. Lincoln rods would break in the middle of the weld. The Hobart rods would break beside the weld. It was quite interesting. Dave

 

[Puddles]

Dave 6013 and I do not see eye to eye!

The first picture is Lincoln’s Fleetweld 37.

This picture is ESAB’s 6013-LV

This is also ESAB’s 6013.

 

[guido]

Hello Showcrop,
Here is a way you can try.
Set the welder so it will burn the rod, when you have the rod burning, push the rod into the work. If continues to burn try a lower setting and repeat the process. Once the rod stick into the work, it is to cold of a setting. Go back to the last setting, and you should be in the ball park, good luck.
Guido.

 

[Stan in Oly, WA]

Hi Puddles,

So often my 6013 looks like what you did with the Lincoln rod. About the main thing I use 6013 for is trying to figure out what I'm doing wrong to make it come out like that. It's kind of a relief to see that it may not be me.

Nice job with the ESAB. What position were those welds made in?

All the best, Stan

 

[bc]

There has been some good threads on welding lately. I guess this is welding 103 or round 3 depending upon the view point and how the thread goes.

Hi Ecnerwal, you raise a couple questions though.

Usually welders are rated in amps and you mention problems with welders having to low of an open circuit voltage. What would be the minumum and optimum open circuit voltage for a welder and where would that info show up? I don't remember that term from my welding classes which my 4 year college refused to give me credit for even though I got A's. I'm not sure any of the 220 amp welders have an adjustment for voltage. I've been looking for a lincoln 225 ac/dc welder but haven't seen one show up in a sale lately and I don't need a new one.

Also wondering what kind of steel you are running into with your backhoe repairs? I've got some welding to do on mine but it appears to me those buckets and other steel would be more of a high carbon than mild which would suggest using the LH 7018. I suspect 6011 would work fine for welding some kind of new bracket or a chain and/or hook.

I spent some years in the oilfields and everything we did was 60(whatever, I forget), pink rod for the root pass and LH 7018 for the final passes on surface pipe and for propane pipelines. I even welded up a 10' pup joint out of drill pipe which is a high tensile strenght steel and used it to pick up 3500' of drill string with no problems. I had it on a rack so I could roll it as I welded, took my time, used the grinder, and laid a nice bead with 7018 if I say so myself.

 

[Welding man]

6010 or 6011 does not make an ugly weld if it is done correctly . It makes a beautiful weld. It should look exactly like an aluminum weld made with TIG.It should look like a row of dimes spread out in a row. 6010 and 6011 are deep penetrating, fast freeze electrodes.You step foreward, gouge out a hole and drop back and let it fill. Stepping foreward, the exact same amount and back, pause and let the crater fill makes the ripples exactly the same.Proper technique is the answer.

 

[Puddles]

I don’t really remember Stan. But I’m confident by looking at them the first two pictures were flat; the third picture is definitely vertical up.
What little 6013 I’ve ever run in my opinion you really have to watch the rod angle, and arc length. The vertical up I ran it with the same technique as I do with Innershield wire. I build a ledge / bridge, pick my hand up and point the rod / gun slightly down. In both cases it forces the slag down behind the puddle.
It is painfully obvious in the first picture I did not use the correct rod angle, so I got all that slag inclusion!

 

[Puddles]

bc, Open Circuit Voltage, (OCV) to a degree confuses me. I have a Miller inverter that has adjustable OCV, low range is between 9 to 14-volts, the high setting is 95-volts. This machine also has a dig setting, Lincoln calls it Arc Force. With this machine set on the high setting for OCV, and if I set the dig below say 80% I can’t hardly blink without sticking a 7018 rod! I don’t ever go below 95% on the dig when running 7018, this way I don’t have to worry about sticking a 7018 rod.

Ok for the confusing part I have a few SA-200 engine drives, they all have a fixed OCV setting of 40-volts. I can’t hardly get a 7018 rod to stick, I mean I have to really try! :?
Maybe someone here more knowledgeable than I can explain this?

 

[Flurette Farm]

Probably overhead..!!!!!!!!

 

[showcrop]

thanks, Gentlemen lots of good info. My stick welder is a Lincoln 225. That part about rubbing the flex off should help a lot, because restarting was where I had most of my problems. Since I use pretty much just mid steel I'll probably get some more 6013.

 

[fixerupper]

To get the flux off the end give the tip of the rod a little pinch with your pliers and the flux will fall off. It kind of wakes you up if you do this when your shoes are wet and the pliers are uninsulated. Jim

 

[Anonymous-0]

So, do you think you'd pull out the 6013 to do a high strength weld repair?:wink: The Esab looks good. You could have a buzz box with 60 OCV and struggle to strike an arc but a good welder like an inverter would have no problem with 60 OCV. The SA 200 has adjustable OCV to some degree but not as much as the SAE 400 with dual continuous control. I think on the SA 200 it is about 60 to 90 OCV. The 40 volt figure is used for the duty cycle rating, Ie/ 200 amps @ 40 volts and 60% duty cycle. I think the duty cycle is better with a higher volt rating. I saw a spec. for welder that claimed it had 60% duty cycle even at 40 volts. On an SA 200 if you wanted a soft arc with less OCV you would set the machine on a low setting within the range. If you wanted a more digging arc, you would set the machine on a high setting within the range. That's why the coarse adjustment ranges overlap. You could run the same rod at the same amps in 2 different ranges, one near the top of the range or the other at the bottom of the range. If you look on some SA 200 control panels, it will say fine current adjustment and open circuit voltage under the fine adjustment control. It's funny all the people that complain about 7018 sticking with their buzz box. Give them a machine like a Miller XMT inverter and they'd get flashed because the arc would strike before they were ready. I'd like to get another portable this year but I'll have to see what kind of prices I can find a good used machine for. Don't have enough work for a new machine but always have something to fix or build. Dave

 

[Stan in Oly, WA]

Hi bc,

Open circuit voltage (OCV) is the voltage you measure across the leads when the welder is not welding. It's designed into the welder and not adjustable until you get to a fairly expensive machine. Lincoln 225 amp welders normally have OCV of right around 80 volts, which is ideal in my opinion. Cheap buzzbox stick welders are often hard to weld with because they have low OCV. I have a Chinese 80 amp inverter welder which is great because it weighs only 8 lbs and plugs into a 120 volt, 15 amp outlet. The down side is that it has OCV of only 37.5 volts and you can tear your hair out trying to strike an arc. It has enough amps to run 3/32 7018 but it absolutely won't light one.

Since this is Welding 103 and you're looking for a Lincoln 225 AC/DC welder, let me tell you some things about that welder that most people don't know. Most transformer welders have a low duty cycle at their highest setting but the duty cycle increases as the amperage setting decreases. Not so the Lincoln 225. It is rated by Lincoln at 20% duty cycle at every setting except for 75 amps (which is circled on the dial) which has a 100% duty cycle so that it can be used to thaw pipes. In actual usage, most users feel that the duty cycle is closer to 100% at every setting. Many, many people's experience suggest that this might be closer to the case.

Another thing you might hear about this welder is that before a certain year of production, the windings on the transformer were copper and after that, aluminum. I e-mailed Lincoln tech support a few years ago to ask what year they stopped using copper. A Lincoln historian wrote back to tell me that while the copper/aluminum issue was true of their Idealarc welders, the tombstone welders (he used the model number but I can't remember it right now) were never produced with copper windings. People claim to know someone who has one with copper windings, and other people claim to know someone who picked up a hitchhiker who told them that Jesus was coming real soon, and then disappeared. I don't know about the hitchhiker but I think the copper colored metallic paint that Lincoln used (or uses) to paint the transformer windings might account for some of the confusion about the welder.

Whatever Lincoln did when they built that welder, they got it just right. I've owned several and they always weld beautifully. I think it's by far the best welder you can buy for the price, and since you can get old ones that weld just as good as they did the day they were built for so little, it's a deal that's hard to beat.

All the best, Stan

 

[Anonymous-0]

A 6010/11 can make a very nice weld. Most people with no training don't realize that with these rods, the proper technique is usually to whip it back and forth while welding. They are also about the only rod you can you do a decent strength downhand weld with, using the same whipping technique. Pipelines are done manually with XX10 rods downhand but at higher currents using a dragging technique. Dave

 

[bc]

Thanks guys. I guess if I was looking at an old welder to buy, I'd want to take my multimeter along and check the voltage. Maybe even clamp the ammeter around it while welding to check the amp output.

I know with all things electric, the amperage also has to have voltage. I just figured that a 220/240 volt welder welded at 220/240 volts with whatever amperage you set it at.

I guess the voltage is stepped down some. I would further guess that as the amp setting goes up or as you strike an arc, then the voltage would drop and flucuate some as you use it. Someone can correct me if I'm wrong here.

And another thing, if a welder has open current voltage, then I would suspect it has closed current voltage when being used. Maybe I'm getting into welding 202 now.

 

[Puddles]

Dave far as I’m concerned they can take 6013 off the planet today! :lol:

Before the SAM-400s came out I always tried to grab an SAE-400 when going on a job site. When running wire I liked the infinite control of the main selector, not being limited to 5-gears like the Miller machines or the later model SAs. Far as the fine tune control, when running vertical up with 7018 I like a stiff puddle, so I would try to set the machine where the fine tune control was at the lowest settings. But when welding flat, I like a wet flowing puddle so I would try to set the fine turn in the upper / highest settings. Overhead and horizontal I like it somewhere in between flat and vertical up settings. To a degree this would be an “Old School” Dig / Arc Force function.


bc if you ever run into one of these welders at a price range you can live with buy it! They are one of the best welders ever built. I was shamed into buying one a few years ago for 50.00$, I turned around and sold it to a friend for 50.00, should have kept it, but I don’t need any more welders! :wink:

 

[eastexan]

(quoted from post at 19:45:40 01/29/10) thanks, Gentlemen lots of good info. My stick welder is a Lincoln 225. That part about rubbing the flex off should help a lot, because restarting was where I had most of my problems. Since I use pretty much just mid steel I'll probably get some more 6013.

Showcrop,
If you want a rod that is as easy to use as 6013, get you a 1lb package of 7014 and try them out.
I think you'll like it. It lays a smooth pretty bead and is a stronger weld than 6013.

I worked in a RR shop 30 years ago, and apparently some of the welders at another location had started using 6013 for welding coupler carriers and other heavy applications. We got a company letter that was sent to all locations that said 6013 was to be used for sheet metal applications only and that disciplinary actions would be taken against anyone caught using it on heavier material.
Apparently they had found some failures, and investigated the cause.

Puddles,
Great looking welds. Looks perfect. I never could weld that pretty.
Now-a-days, with my bad elbow and shaky hands, my welds look more like the "Gorilla Welds" (ugly but strong), that I used to make fun of when I was younger. :mrgreen:

Ronnie

 

[bc]

Thanks Puddles, what brand is it? I can't make out the nameplate. I assume it is ac/dc with a polarity switch somewhere.

 

[ric]

start turning the heat down a little at a time and i will bet you will have good results. RICK

 

[Ecnerwal]

As stated by others, OCV is built in an not always adjustable (and not always labeled as such even when it is adjustable). Welders are transformers - you get more amps to weld with by using a lower voltage than the wall current (except for transformer inefficiency, power is equal in and out, so 60 amps at 240 volts gives (nearly) 600 at 24 volts)

Rather than dragging along your meter, you can just look from a known good model.

Most of the backhoe is mild steel. Most of the high-carbon steel is bolted in place (cutting edges) or limited to a cutting edge that's welded in (and more annoying to maintain than bolted-in edge).

While even I can manage a good-looking weld with 6011/6010, the surrounding area gets a lot of spatter and the like that "prettier" rods don't leave. It's not a huge issue, just makes the clean-up more tedious.

The Ford/Chevy of welders: If it's red, it's a Lincoln, if it's blue, it's a Miller - Nearly always true.

 

[Puddles]

bc those are Lincoln IdealArc 250. Yes they are AC DC. :wink:

 

[Anonymous-0]

Idealarc 250's are a better machine than a Miller Dialarc 250. When I went to school, we had both(the Miller was newer) as well as SAE 300 generators and some TM AC and AC/DC machines and a TIG 300. Of course the generators were the smoothest but the Idealarc wasn't too far off. The TIG 300 was about the same as the Idealarc. There were straight AC Idealarc's made too. Red-D-Arc sells a rebadged Idealarc 250 with only DC current. I looked at some SA 200 face plates on the net. They say "current and O.C.V." on the fine adjustment. Dave

 

[bc]

Thanks guys, I'm enjoying the welding classes/wars the last few days. I guess the Idealarc 250 even has copper windings. I think I passed one of those up a while back cause in the picture the paint was so cruddy and it looked so old and it didnt' say anywhere that it was dc as well. One of those or an ac/dc 225 is what I'll look for.

If anyone has a meter I have an experiment to try. Just wonder what the OCV is for different amp settings. And then check to see how much voltage drop if any there is when you start welding at a set amp setting.

And if I was guessing, an idealarc with a dial type amp adjustment wouldn't need a fine tuning OCV adjustment and if there was such a fine tuning adjustment, it would be on a welder with switchable amp increments such as 5 or 10 amp increments.

 

[Anonymous-0]

The newer Idealarc's may have aluminum wires? but they are still an excellent machine. They have a thermal cut out if they get too hot, but rarely do. An AC 225/DC 125 is better than straight AC but not even close to an Idealarc 250 AC/DC.
Open circuit volts on a constant current (stick) welder go down to around 24 volts when welding. You can get a cheap meter to measure to volts. If you have someone else to weld, you can watch the volt meter as they strike an arc and vary the arc length. There will be quite a difference. Usually only higher end machines with different current ranges like an engine drive have adjustable OCV. On a constant voltage (MIG) machine, the arc volts stay pretty close to the OCV. Some MIG machines have a slope control to adjust the voltage drop. A stick machine has a steep voltage drop or slope and a MIG machine has a relatively flat slope. Stainless steel MIG usually needs a higher slope for proper welding. Some MIG machines have inductance control as well which changes the pinch off effect of the wire. Puddles will tell you how much he "hates" his Linde machine with inductance control.:wink: He posted some pictures a while ago of what changing inductance will do.
I don't mind trying to educate people about welding and will try to explain things as best I can. I don't know everything and may make the odd small mistake but I do know the fundamental basics. It can get very frustrating trying to get someone with no formal training to understand that they are incorrect. A lot of people wouldn't bother but I think it is important to post the correct information. People could be injured following the wrong information. I just read the most ridiculous comment I've ever seen on the other forum. A repair broke that was brazed but held when it was MIG welded. Well D'oh, as Homer Simpson would say. There's lots to learn regarding welding. Sometimes it's like beating a dead horse but I hope I'm helping people get better results with their welding projects and equipment requirements. Dave

 

[Puddles]

I found this chart in the Lincoln Procedure Handbook, (The Bible)!

Variable Voltage is just another term for Constant Current.

 

[Anonymous-0]

Have always been told that if you're running a little hot or the gap gets a little too big, just lengthen the arc a little and it will lower the amps a bit. You must have a new "Bible". I had one but loaned it out and never got it back. I think they update it every year and it doesn't cost very much for the size of it. Lots of cool pictures in it though, like the rebar for the rocket launch facility. That's a lot of welded rebar! Dave

 

[Puddles]

(quoted from post at 18:37:57 01/30/10) Have always been told that if you're running a little hot or the gap gets a little too big, just lengthen the arc a little and it will lower the amps a bit.

Now that is strange, I’ve always found it to be the opposite!

Or at least it will get hotter if you lengthen the arc gap. May just up the voltage.

I’ve had this “Bible” for at least 30-years, maybe its time to update.

 

[RodinNS]

I too have always observed that a longer arc will burn hotter...

Rod

 

[Anonymous-0]

I agree but even the chart below says the contrary. If I'm running a root pass and the key hole gets too big, sometimes you can just push the rod in real tight and it helps. Dave

 

[bc]

Now this is where it gets confusing again. After I saw this chart yesterday, it made sense to me because my little 110 volt mig welder instruction book says that to increase the heat and penetration, you turn up the wire feed speed. To my way of thinking, turning up the wire feed speed is the same as pushing a stick into the work and therefore according to the chart, the shorter arc lenght puts more current amps onto the weld.

That was great till you guys posted about pulling the stick out further to make a hotter weld and more penetration. It's been about 30 years since I've done much welding but I recall that as well. And as I recall, pushing the stick in will cool it down and help control the puddle a little better and get less penetration.

Technically, varying the rod distance/arc length never changes the amp setting on the machine which stays constant. It would be my guess that if you replaced the bottom axis of the chart from Current-Amps to something like welding heat, then the chart would be accurate. The alternative is that changing the rod distance/arc length does something to the electrical equation that is going to require one of electricians to step in and explain it. Such as the arc length acts like some type of resistance or capacitance in the circuit that causes volts and amps to change but that still doesn't account for the heat applied to the metal.

I assume the basic equation is still volts x amps = watts/power/heat.

Getting into welding 404 now.

 

[Fastjack]

Hello fellas, I need some help. I am an amature welder. I learned to weld on an old Lincoln 225 AC welder. Most of the stuff I weld is thin, mild steel so my rod of choice is 6013 (usually 1/8), with which I produce some very pretty welds.

However, I recently purchased a new DC welder -- a Miller Bobcat 225 -- but when I tried using my 6013 rods the welds were terrible. I was getting heavy spatter, arc blow, and air pockets. It seemed as if I was running extremely hot. I tried adjusting the amps down but then I got NO penetration, lots of bubbles and just as much splatter. I thought my rods might be damp so I bought another box and got the same effect.

My machine, a Miller Bobcat 225, has a normal set up of DCEP (which is direct current reverse polarity). My question is, can I change the polarity of my welder (to DCNP) without hurting my machine? And if so, how? Most DC welders have a switch where you can change the polarity, but I cannot find one on my machine, and I cannot find anything in the owners manual to help me.

 

[Puddles]

What little 6013 I run, I run it on DCEN.
Just switch your leads, stinger / electrode holder is normally on the + stud, put it on the – stud, now your running DCEN! :wink:

 

[Fastjack]

Thanks a lot, Puddles! That is what I thought, but not really knowing I was afraid to do it. That machine cost $3,000.00, and I didn't want to damage it any before I really got the chance to use it.

 

[Puddles]

I have a 6,000.00$ Tig / stick machine and that is how I have to change polarity. You’d think for 6-grand Miller would install a switch! :roll:

 

[Ecnerwal]

Pair of (300A?) camlock quick disconnects is how I do it on mine - tape color coded to:
Electrode yellow
ground clamp green
+ red and
- black

easy to see how it's hooked up that way. Takes seconds to switch. Cost a few bucks at the welding store, but worth it. If you ever need extension leads, it makes that easy too.