Avoiding arc start porosity on 7018?

[BrooklynBravest]

I never leave the nest so everything is always MIG and sometimes TIG.

For the sake of having the ability I'm practicing on scrap here and there.

This is 1/8" 7018 on 100 amps from a powermig 210.

I think my beads are "decent" but the arc start is always ruined with porosity.

I have tried starting 1/2" or so inward, and quickly whipping back once its lit as well as slowly bringing it back. Nothing I try seems to improve it.

[Oscar]

Try 1" and slowly move it back. Make sure you get the right arc length when you get to the apart of where the bead is going to go.

[villageblacksmith]

Just curious what brand of rod that is. And, a lot of times the need for clean material gets (over) stressed in my opinion, but this time it did get my attention. It looks like there is a fair amount of rust in the area where you have the porosity. Could just be how the photo looks.
About the only suggestions I have come in the form of questions. Is the porosity coming from an unused electrode? Or from re-strikes. If it is coming from an unused electrode, the first time you use it, then it "could" be when you strike it to begin welding, your fear of sticking it to your plate is causing you to lift the electrode too high, initially giving you too much arc length.
If porosity is coming from when you re-strike, then I would suggest grinding, filing, sanding, or whittling the end off the electrode before re-striking. Some 7018 rods seem more prone to get a mixture of molten slag and weld material glued to the end of the rod at the end of a weld, causing porosity when beginning the next pass
But yes, the rest of your beads look fine. Don't forget that 7018 works best without any of the whipping, or forward and back motion, that is often employed with the 6010/11 electrodes.
Good luck!

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[cwby]

My sweet spot for 1/8 7018 is 115 to 125A. Maybe a little cold @ 100A. I strike ahead of my start, long arc a little to heat the rod & stabilize the arc (engine drive), then move back to start & stuff it in to make sure I have a short arc then pause for just a micro second to let a clean puddle form. I find that a cold rod nearly always leaves a little porosity.

[M J D]

Turn your amps up. On that practice piece after a bead or 3 you would be running too hot tho. On 1/8" 7018 I would be in the 115-130 amp range depending on thickness, joint configuration and position. The 2 main causes for porosity ( excluding rust, paint or oil) are too low of amps or starting with too long of an arc.

[William McCormick]

I never leave the nest so everything is always MIG and sometimes TIG.

For the sake of having the ability I'm practicing on scrap here and there.

This is 1/8" 7018 on 100 amps from a powermig 210.

I think my beads are "decent" but the arc start is always ruined with porosity.

I have tried starting 1/2" or so inward, and quickly whipping back once its lit as well as slowly bringing it back. Nothing I try seems to improve it.

Switch to 7016 you cannot go wrong. You can bury the rod and it just cuts deep and leaves a nice weld. It starts so nice too.

Sincerely,

William McCormick

[BrooklynBravest]

Thats a piece of HRPO 3/16" plate scrap from my plasma table.

Its definitely not rusty or oily but I didnt take any time to prep the surface either.

I'd prefer to learn 7018 because its such a commonly used rod. I'm literally just burning a couple rods every time I go out for practice.

[albrightree]

What are your Arc force, and Hot start settings ?

Is your polarity correct (sometimes I have things switched around because its multi purpose, it happens occasionally), sometimes going to "Home" and going through the settings helps me remember.


Seems a little cold amperage wise for most 1/8" 7018 work, but if you need to run that amperage( welding thinner metal and or vertical ) , increase your hot start.

3/32" 7018 runs good 85-100 amps.






Good luck

[BrooklynBravest]

What are your Arc force, and Hot start settings ?

Is your polarity correct (sometimes I have things switched around because its multi purpose, it happens occasionally), sometimes going to "Home" and going through the settings helps me remember.


Seems a little cold amperage wise for most 1/8" 7018 work, but if you need to run that amperage( welding thinner metal and or vertical ) , increase your hot start.

3/32" 7018 runs good 85-100 amps.

I messed with it a bit. I tried 115 amps, the puddle never felt like an issue it all ran smooth just the porosity.

Hot start i tried from 3 up to 10. Arc force was 3.

[Louie1961]

This is a common problem, common enough that Lincoln publishes guidance on how to avoid it

https://www.lincolnelectric.com/en-g...ty-detail.aspx

[Meltedmetal]

Credit to Louis 1961 from 2015

http://forum.weldingtipsandtricks.co...pic.php?t=7029
https://www.lincolnelectric.com/en-u...ty-detail.aspx

[JDM Welder]

Here in Japan, we call this kind of porosity from LH rods "blow holes," and it mostly caused by what we call "start blow." Not to be confused with arc blow due to magnetic forces, but the same effect with the arc wandering around. To mitigate the effect, try starting the rod quite a bit farther forward, like maybe a full inch. After the back step, hold the rod there for a second to let the puddle build, and arc firmly establish, and keep the rod angled back. Here's a video on a A-2F qualification with LB-47 (E7016) showing the back step and rod angle. English subs, but not all clear translations...

[farmersammm]

Here in Japan, we call this kind of porosity from LH rods "blow holes," and it mostly caused by what we call "start blow." Not to be confused with arc blow due to magnetic forces, but the same effect with the arc wandering around. To mitigate the effect, try starting the rod quite a bit farther forward, like maybe a full inch. After the back step, hold the rod there for a second to let the puddle build, and arc firmly establish, and keep the rod angled back. Here's a video on a A-2F qualification with LB-47 (E7016) showing the back step and rod angle. English subs, but not all clear translations...

That really looks nice(actually BEAUTIFUL) until the last pass. It's a bit too proud of the plate. Too much metal piled up.

It's a booger to judge bead height in these kind of welds, been there, done that I find that viewing the puddle from the side works best, if you can get in a position to look from this angle. Flat welds can sorta suck in a way.

See how the weld is not extremely convex, but relatively flat, but still blending nicely with the edge of the joint. A side view gives you a very good approximation of bead height.



All welds not more than maybe 1/16 over the top of the plate.

This is a funny!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I was just starting to lose my eyesight when I made these welds. I took this pic in the mirror I think, right at the time this project was in process. I'm probably at my peak here, and that's about as good as I'll ever weld again for the remainder of my days. The welds made since, haven't been up to snuff. I'm getting closer to committing to cataract surgery I guess And I'm not keen on doing welding critique these days, because I'm not doing much better since the eyes started going.

Anyways.............you got some good stuff there, just try to flatten out that final pass

[52 Ford]

That really looks nice(actually BEAUTIFUL) until the last pass. It's a bit too proud of the plate. Too much metal piled up.

It's a booger to judge bead height in these kind of welds, been there, done that I find that viewing the puddle from the side works best, if you can get in a position to look from this angle. Flat welds can sorta suck in a way.

See how the weld is not extremely convex, but relatively flat, but still blending nicely with the edge of the joint. A side view gives you a very good approximation of bead height.



All welds not more than maybe 1/16 over the top of the plate.

This is a funny!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I was just starting to lose my eyesight when I made these welds. I took this pic in the mirror I think, right at the time this project was in process. I'm probably at my peak here, and that's about as good as I'll ever weld again for the remainder of my days. The welds made since, haven't been up to snuff. I'm getting closer to committing to cataract surgery I guess And I'm not keen on doing welding critique these days, because I'm not doing much better since the eyes started going.

Anyways.............you got some good stuff there, just try to flatten out that final pass

Go ahead and get the damned surgery. No reason to waste time. Get it. Really.

Nice welds by the way. Thought it was MIG at first.

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[52 Ford]

I never leave the nest so everything is always MIG and sometimes TIG.

For the sake of having the ability I'm practicing on scrap here and there.

This is 1/8" 7018 on 100 amps from a powermig 210.

I think my beads are "decent" but the arc start is always ruined with porosity.

I have tried starting 1/2" or so inward, and quickly whipping back once its lit as well as slowly bringing it back. Nothing I try seems to improve it.

If i think about it, I'll run some 7018 tomorrow and try and make some porosity at start. I dont think I've ever had that issue.

Damp rods, maybe? Material not clean enough? Some other contaminants on the rod? Might want to try a new pack of rods just to be sure.

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[Sberry]

They used crappy Chemtron Atom Arc on a nuke I was on, cost them millions for terrible starts.

[driz]

That really looks nice(actually BEAUTIFUL) until the last pass. It's a bit too proud of the plate. Too much metal piled up.

It's a booger to judge bead height in these kind of welds, been there, done that I find that viewing the puddle from the side works best, if you can get in a position to look from this angle. Flat welds can sorta suck in a way.

See how the weld is not extremely convex, but relatively flat, but still blending nicely with the edge of the joint. A side view gives you a very good approximation of bead height.



All welds not more than maybe 1/16 over the top of the plate.

This is a funny!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! I was just starting to lose my eyesight when I made these welds. I took this pic in the mirror I think, right at the time this project was in process. I'm probably at my peak here, and that's about as good as I'll ever weld again for the remainder of my days. The welds made since, haven't been up to snuff. I'm getting closer to committing to cataract surgery I guess And I'm not keen on doing welding critique these days, because I'm not doing much better since the eyes started going.

Anyways.............you got some good stuff there, just try to flatten out that final pass

Hell just do it and be done. Cataract surgery is nothing but an office procedure these days. It’s like getting a tooth pulled . Also just like getting a tooth pulled more or less EVERYBODY is going to get it done eventually.


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[52 Ford]

Hell just do it and be done. Cataract surgery is nothing but an office procedure these days. It’s like getting a tooth pulled . Also just like getting a tooth pulled more or less EVERYBODY is going to get it done eventually.


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Exactly.

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[52 Ford]

They used crappy Chemtron Atom Arc on a nuke I was on, cost them millions for terrible starts.

I wonder if the ESAB Atom Arc have the same problem. I have about 40 pounds of 7018-M in sealed cans. Never burned one.

I don't guess they would since they're still on the market.

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[William McCormick]

If you have not tried 7016 rods they are amazing rods. You can do horizontal at 105 amp with 3/32" rods, dig in deep, and not have the puddle run. If you are doing butt joints either pipe or plate, you just leave the rod thickness gap, and it just pushes a beautiful puddle to the inside when you are overhead. You have to watch you do not push too much material if you are vertical or over the top of the weld. 7016 needs no drying out or oven, these things just go. You will not believe the penetration you get when you keep a short ARC. My friend Lou Stimberger used them and built hundreds of thousands of tons of steel docks with that rod, I heard he recently passed away but his work lives on.

The 7016's have half the thickness of flux as the 7018's do, it is the excessive flux of the 7018 that causes that porosity.

Sincerely,


William McCormick

[Welder Dave]

You could try sticking the rod to the plate for a couple seconds to heat up the rod. Have done this with new rods working on pressure vessels where we took boxes of rods that weren't in the electrode oven. 7016 is not common. Some brands of 7018 are more prone to start porosity than others. I ran some 10018D2 and it was terrible for start porosity even when it came straight out of the oven.

[52 Ford]

Even if it isn't a low-hy, getting a little heat in the rod seems to always help me with stsrts.

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[12345678910]

Thats a piece of HRPO 3/16" plate scrap from my plasma table.

Its definitely not rusty or oily but I didn't take any time to prep the surface either.

I'd prefer to learn 7018 because its such a commonly used rod. I'm literally just burning a couple rods every time I go out for practice.

I agree with that, but I wish I'd started with a box of 7014 first.

I was a kid, got frustrated and didn't try again for twenty years.


I find short sessions not as helpful as a longer session.
It takes time to get into the groove

Wall Mountain Arc weld videos
https://www.weldingvideos.com/







I started by cutting rods in two or three pieces , for less twang and wobble on starts; but it also gave me more practice on arc starts too.




Listen to the sizzle, you can really hear when you're long arcing and when it's right.

I had huge problems with sticking the rod and
Upping heat definitely helps

If it's just for practice, the smaller 3/32 rod goes slower, takes less heat, gives you more rods per pound/package/dollar

Unless you're buying the sealed tennis ball tubes, try high temp drying the rods according to the instructions, and I use a toaster oven as rod oven.
It does make a difference.

[52 Ford]

I agree with that, but I wish I'd started with a box of 7014 first.

I was a kid, got frustrated and didn't try again for twenty years.


I find short sessions not as helpful as a longer session.
It takes time to get into the groove

Wall Mountain Arc weld videos
https://www.weldingvideos.com/







I started by cutting rods in two or three pieces , for less twang and wobble on starts; but it also gave me more practice on arc starts too.




Listen to the sizzle, you can really hear when you're long arcing and when it's right.

I had huge problems with sticking the rod and
Upping heat definitely helps

If it's just for practice, the smaller 3/32 rod goes slower, takes less heat, gives you more rods per pound/package/dollar

Unless you're buying the sealed tennis ball tubes, try high temp drying the rods according to the instructions, and I use a toaster oven as rod oven.
It does make a difference.

Impressive mustache.

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[52 Ford]

I don't burn much 7018, so I baked about 20 pounds of them and vacuum packed them in bundles of 5 and stuck them in 10 pound cans with a little desiccant.

I just turn the oven up to 500 and let them cook for a couple hours to dry them. Nothin' like the smell of fresh baked electrodes. Works for aluminum rods, too. I had about 250 dollars worth of those get wet and the flux turned to like a paste that wanted to peel off when I pulled the rods out the box.

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