Worm tracks

[Oscar]

Nozzle diameter: 5/8"

Contact tip recess into end of nozzle: 1/8"

As suggested on Miller chart on the welder voltage 24.3

Speed: 380 IPM

Miller suggests 25 CFH, I have tried 30,35, and 40.

The large nozzle diameter coupled with "only" 40CFH confirms what I think might be it. See, notice that the CFH rate range given by manufacturers rarely/never states for what nozzle diameter it is valid for? That would be like suggesting a TIG flowrate without specifying what the user's cup diameter is! I suspect they anticipate users will be using a 1/2" nozzle orifice diameter. 25CFH is wayyyy out in left field for a wire that needs ¾" to 1" CTWD (typically).

Keep the nozzle to keep the orifice ≈¾" from the joint, that way you have ≈7/8" CTWD. If you need to, get a ruler/tape measure whatever and make sure what you are thinking is accurate, really is accurate for the CTWD. Next, up the C25 gas flow to no less than 45CFH. Better yet, just try 50CFH. While it might seem excessive, I have empirically found that the [low] CO2 content is directly related to the probability of producing worm tracks with E71T-1C/1M wire:

Mixing Argon and CO2 myself, I found anything less than 20% CO2 on brand new wire started to produce worm tracks. I used 40CFH total because I was using a 1/2" Nozzle. Doesn't seem like much of a difference compared to 5/8", but do the math and compare the area increase/difference, or just trust me when I say that a 5/8" nozzle is 56% larger than a 1/2" nozzle!)


That is the reason I am suggesting for you to up your gas flow to 50 CFH at least. If that doesn't work, you can always pop open your C100 tank and run pure CO2.

As for WFS/V, 24V seems a smidge low for that wire speed. Depending on whether you were looking at it or not, you were likely seeing the tip of the wire either short-circuit or glob(ular) into the puddle, were you not? If that is indeed the case, increase it to 27V ± 1V to see how it responds. The wire should be exhibiting a near spray-like transfer where the wire tip starts to "needle" and decreases in diameter just slightly as the droplets are propelled into the base metal. That is what I have seen, but perhaps it is not the same for all wire brands. Just something to look at/think about. 380ipm is roughly 250A with that wire. Once you get the initial passes done, would it not be wiser to up the WFS/V? 450ipm @ 29-30V would net you about 300A give or take. Remember, those entrapped gasses need to escape, so if it is super-cooling due to the large mass of the base metal, the slag could be solidifying too quickly.

PS: if the thought of using so much shielding gas doesn't appeal to you, a longer nozzle can make better use of the shielding gas especially if it is C25 (because of the inherently low CO2 content). With a nozzle of the 'just-right' size, you can recess the tip enough that you can run what appears to be 'short-circuit-like' CTWD but you are really using a long CTWD, except that you can get away with a lot less shielding gas flow. I call it the Super Mega Nozzle™©. I can run a "regular" 7/16" to 1/2" nozzle-to-work distance and the lower flow-rate doesn't affect it because it's able to flood the area a lot better.






I hard to tell from the pic, but I give it a ≈2.8° downwards droop, because since that is what the wire itself does due to the inherent curvature from the winding on the spool, it better directs the shielding gas to cover the wire (and thus the puddle) coaxially instead of the wire coming out off-center out the nozzle orifice (the wire itself is off-center by about 1/8" by the time it is 1" out of the tip). This nozzle had a bit much at 4.5°, so I ended up tweaking it until I found the right angle that worked for me (shown in the previous pics).

[Welder Dave]

File a patent before someone steals your idea.

[Willie B]

Thank you. That is a lot of information. I guess I was thinking of the large nozzle as a similar effect to a gas lens in TIG. Thought I'd reduce turbulence in the gas. I'll find a smaller nozzle, meanwhile increase gas flow & voltage.

In the past successful welds this seemed more similar to a spray weld process where the wire disappeared into a needle just before contact. The superior ability of dual shield to stay put without sag is the big appeal to me.

I hope to find time this weekend to try your parameters. I can't find Bernard parts locally, Airgas orders them for me, but hazardous material, handling, shipping, fuel, and tax once brought the price of a stubby TIG back cap to $48.!

[Louie1961]

I'll find a smaller nozzle, meanwhile increase gas flow & voltage.

Bill, if you are getting true porosity and not just worm tracks, the issue is gas coverage or lack thereof. I would increase the flow rate and consider using straight CO2. I would also put up better windbreaks around your welding area to keep the breezes out. Not sure I would increase the voltage as that may lead to the actual worm tracks.

[Louie1961]

Also, you should give more credence to the wire manufacturer than the welder manufacturer regarding operating procedures. Not sure which version of Ultracore you are using, but all the operating procedures are available from Lincoln online. https://www.lincolnelectric.com/asse...M71/c31251.pdf

[Oscar]

Bill, if you are getting true porosity and not just worm tracks, the issue is gas coverage or lack thereof. I would increase the flow rate and consider using straight CO2. I would also put up better windbreaks around your welding area to keep the breezes out. Not sure I would increase the voltage as that may lead to the actual worm tracks.

For the voltage, I was going by the Lincoln literature that suggests 24V is more adept to running 300-350 IPM. But you're right that too much could cause more worm tracks. This is where Willie needs to be careful and try only one change at a time.

Willie, smaller nozzle won't necessarily help, because you would want more total CO2 present in the shielding gas. A smaller nozzle @ 40 CFH is not the same as a larger nozzle @ 50 CFH. At 50 CFH you're "presenting" more CO2 to the puddle, which I feel will help. Your 5/8" nozzle is just fine so long as you bump up your gas flow to the 48-53 CFH range (I suspect this will help). If it doesn't then you move on to something else to try.

[Oscar]

update?

[Willie B]

It's 8 AM here. Yesterday was our 39th anniversary. It was Nancy's day. I'm heading out to do a bit of fabrication. I'll try more gas.

Should I try more volts, or fewer IPM?

[Oscar]

It's 8 AM here. Yesterday was our 39th anniversary. It was Nancy's day. I'm heading out to do a bit of fabrication. I'll try more gas.

Should I try more volts, or fewer IPM?

What ever you do, do it systematically by only changing one thing at a time, and write down notes. Otherwise you will come back and say you "tried everything" which will help no one.

[Willie B]

I placed three sheets of plywood for wind control It won't fit in the garage. Doors are 8' tall, hoe is at least 8'9" tall. 26' bays. hoe is 30+ long. With enough effort I can extend the hoe to the back wall where there would be less air current. I haven't tried that yet.

Today it was plywood wind screens, and more shielding gas, being diligent about CTWD.

No improvement today.

This project has taken too long! My customers & my wife are demanding an end. MIG is doing the job. Dual shield is wasting time.

A friend & customer was pressing for us to do a three day earth moving project. I jumped the gun on the thumb build & went to work with a brace not yet there. I reasoned it was plenty strong without, I'd be careful.

It bent. First order of business today was straightening the 1X4 11" long the hydraulic cylinder acts on. I built a box to use a 20 ton hydraulic jack to push it back to shape. Didn't want excess weld I'd then have to grind off. First weld to break at 40000 lbs was non eventful.

The mess you see in pictures is the first broken weld repaired in a not pretty way. Ultimately two other welds failed simultaneously in an explosive manner.



Dual shield with plywood wind screens. 50 CFH Argon 75/CO2 25. Lincoln Ultra core. .045" My regulator won't go higher.
Barely perceptible wind. If i dropped a dry leaf it'd land a foot vertically from where it was dropped.

[leightrepairs]

hat specific UltraCore? There are different variations and not all use mixed gas.

[M J D]

Try a new spool of wire. I have ran out of gas while welding and it wasn't anywhere near that bad before I realized I was running out.

[JayWal]

I find dual shield fairly forgiving, the way those beads look it seems like you have a major issue like bad gas or wire, more than just a technique of CFH issue. Check out this beautiful turd I laid down when I forgot to open my gas. So thats's with NO shielding gas at all, yours look almost as bad.

Thats with Lincoln wire as well. 71Supreme .

Sent from my SM-G970W using Tapatalk

[djd775]

I don’t know what your prep is like, but I have experienced similar porosity with Esab Dual Shield 70 Ultra Plus. In my case it’s almost always contaminants....traces of grease, paint, rust, plasma cutter dross,etc. IME, dual shield is less tolerant of contaminants than solid wire mig.

I stand to get flamed for this, but I sometimes find that foreword/back manipulation of the puddle helps in the case of contamination. Run ahead 1/4” to get the crap boiling out, then fall back and dwell in the puddle to fill out any pockets left behind, then run ahead again.... Also, it seems constant oscillation helps to encourage the contaminants to float out - don’t stay straight and steady like you normally would with dual shield. Not in line with approved procedures I’m sure, but it seems to help.


Edit....looking back at your pictures, I’m even more convinced that your culprit could be rust/paint/grease/water. Is this possible?

Sent from my iPhone using Tapatalk

[Oscar]

Lincoln Ultra core. .045" My regulator won't go higher.

Those are very bad as in, not just worm tracks, there is porosity. Like someone else mentioned, there are lots of Lincoln Ultra-core's.

Have you every successfully welded with this exact roll using C25?

If you look HERE, some Lincoln Ultracore wires use only 100% CO2. Which exact Ultra Core are you using?

[Willie B]

Those are very bad as in, not just worm tracks, there is porosity. Like someone else mentioned, there are lots of Lincoln Ultra-core's.

Have you every successfully welded with this exact roll using C25?

If you look HERE, some Lincoln Ultracore wires use only 100% CO2. Which exact Ultra Core are you using?

I've used it a few times. I limit it to heavy steel welded out of position. The roll is a couple years old. I built a skidding arch for the bulldozer. I did have a few spots I had to grind out when it got breezy while welding. That was mostly 1" thick stock.

I rebuilt a backhoe bucket a year ago with no troubles.

It is stored upstairs in a plastic bag when not in use. The second floor of the garage is HOT in summer, and a bit warmer than outdoor in winter.

[Oscar]

So again to reiterate, which ultra core are you using exactly?

[Willie B]

So again to reiterate, which ultra core are you using exactly?

Not much information. I take it to mean 71......85000 tensile.

[12V71]

I've used it a few times. I limit it to heavy steel welded out of position. The roll is a couple years old. I built a skidding arch for the bulldozer. I did have a few spots I had to grind out when it got breezy while welding. That was mostly 1" thick stock.

I rebuilt a backhoe bucket a year ago with no troubles.

It is stored upstairs in a plastic bag when not in use. The second floor of the garage is HOT in summer, and a bit warmer than outdoor in winter.

Hot in summer? in a heavy plastic bag that has already been opened and resealed without any moisture eaters? I'm almost betting that is the equivalent of "steaming" moisture into that wire. I don't know the whole story, but it kinda makes sense to me. Your mileage may vary, but i think you need to try some new wire to be sure.

[Willie B]

Hot in summer? in a heavy plastic bag that has already been opened and resealed without any moisture eaters? I'm almost betting that is the equivalent of "steaming" moisture into that wire. I don't know the whole story, but it kinda makes sense to me. Your mileage may vary, but i think you need to try some new wire to be sure.

I don't know. Seems a logical theory.

KD welding is the local heavy user of this product. He is severely overworked. Though he'd probably make time to help sort out my problem, I'd feel very guilty asking.

[Oscar]

I see. Just wanted to make sure that wire was indeed compatible with mixed shielding gas.

I did try a simple bead on the horizontal, it was flawless.

So you said with this exact wire, just before you got worm tracks/porosity, you were able to lay down a horizontal bead with zero issues? Or was that some time ago and not during this time-frame?

[TimmyTIG]

Is there any way you can bake that wire? I know you probably don't want to just chuck it, but those welds ain't gonna cut it.

[Welder Dave]

I agree that storing for 2 years in varying temperatures likely introduced moisture into the flux. Wire might not be rusty because Lincoln puts a graphite coating on the wire. Maybe baking it for several hours would help but that might be hard to do with a fibreboard spool. Should work fine with C-25 shielding gas. How clean was the steel you were welding? Could be a combination of things contributing to the worm tracks and porosity. See page L13 of the 2nd link concerning storage conditions. I suspect your wire is contaminated from improper storage. Keep the unused wire in the house where the temperature is more consistent. Dual-Shield isn't the best option for occasional welding where it takes month's to use up a spool.

https://www.lincolnelectric.com/asse...1A85/c3126.pdf

https://www.lincolnelectric.com/asse...ure/mc1578.pdf

https://www.dryrod.com/technical-art...lux-cored-wire

[Willie B]

I see. Just wanted to make sure that wire was indeed compatible with mixed shielding gas.



So you said with this exact wire, just before you got worm tracks/porosity, you were able to lay down a horizontal bead with zero issues? Or was that some time ago and not during this time-frame?

Same day. Nasty worm tracks & porosity, I tried a simple bead on a piece of 1" thick flat. While it wasn't hot enough, it laid down flawlessly. Conditions were identical except position & no joint to fill.

Been having issues with the wire bird nesting so I've thrown away maybe 50 feet of wire.

[Willie B]

Is there any way you can bake that wire? I know you probably don't want to just chuck it, but those welds ain't gonna cut it.

It's on a pressed sawdust reel. At the pellet mill they heat pine sawdust to 600 degrees with nearly no oxygen present. I doubt I'd get away with that in Mrs. B's oven.

I will find time to get it indoors, and try again. A new roll would be worth it if it solves the problem, or a waste of money if it doesn't.