New 185dv owner with a porosity issue

[Deep Six]

Hi all!

I've been doing stick and mig welding for several years now around my shop, equipment, etc. Nothing professional, I think I'm referred to as a "hobbyist". I've been wanting to get a tig setup for a while mostly because I run into situations with aluminum and a need for clean welds on stainless when working on cars. Well the time came last November when Everlast started the big end of year sale. I'm now the happy owner of a 185dv!

I'm local to HTP and they were running a special on 55 cf refurbed tanks so I bought one and had them fill it with argon for me. I had the tank before the welder even arrived. I grabbed some 3/32 2% lanthanated tungstens off Amazon along with various fillers and a gas lens kit. I set everything up according to the directions in the manual and got to welding on some A36 that I carefully prepped to a rough polish with a new 80 grit flapper wheel.

I think I've got the technique down pretty well and can hold a good tight arc and make nice puddles. However I'm having a nagging problem with porosity that I can't seem to beat. Gas flow rate (tried 10-50 cfh), tungsten prep, torch angle (tried to stay close to 90 deg), arc length, or amps doesn't seem to make a difference. As the puddle cools behind the arc, these craters develope. Anybody got any ideas?



Also, I tried aluminum a bit too. 1/8x2" flat, brushed clean with a new stainless brush. Set the welder at 110 amps, ac electrode in the neg port of the welder, 32% cleaning, 120 hz, freshly prepped 3/32 lanthanated tungsten. I couldn't get the arc to focus at all or make a visible puddle. It'd just buzz hard and then eventually large sections of the piece would melt and produce black goop.



At this point I'm thinking I got a bad tank of gas. Anybody got any other ideas?

[aland]

Let me first say I have very little experience with tig, and have only used my DC tig welder twice.

To me it looks like contamination that could be causing the porosity. Hopefully someone will come along quickly to give a better opinion.

Normally I've seen it recommended to set the post flow to about 5-7 seconds, so the arc tapers off on aluminum, that keeps the craters from creating. However in this case there are craters in the middle of the weld, so you have either stopped and started the weld or the arc may have changed going long to short and long again, that I don't know.

I'm sure someone else with more knowledge of aluminum tig welding will be along shortly to help, such as Mark from Everlast, Rambozo, zoama or Christian.

Alan

[christian]

Yeah,

The OP is probably right about it being bad gas. I mean, I've never had a bad tank of Argon myself, though.

But to rule-out anything that might able to be resolved onsite and without getting a fresh tank of Argon, I'll speculate further.

Sometimes hot rolled steel will throw porosity like that at the end of a tank for me. But I think sometimes it can occasionally also be either the base metal or the filler, as some TIG filler has more or less deoxidizers, as denoted in their code number. I mean, it looks like you ground down the base metal first and were not trying to TIG weld over the mill scale. But, maybe it could be your flap disc leaving imbedded stuff that crops up as contamination/porosity.

But, of course, that aluminum is a mess, so it's undoubtedly a gas problem or an occlusion somehow. Although, it looks like you weren't adding any filler on the aluminum. So, I'd try adding some filler, to see if the arc and puddle likes the filler better than the base metal, since some aluminum is not weldable, and some of it is clear anodized, which can be problematic to weld.

[Deep Six]

Yeah, I don't mean to keep you guys in the dark. I just didn't take any pictures to post beyond those in the start of this thread. I will try to remember to snap some next time I'm out there. I'm afraid all they're going to show is a clean, balled tungsten and clean aluminum (before) and dirty melted aluminum (after).

What would be really cool is a video. Maybe I'll try to get some help holding a camera behind a spare helmet.

I understand what you mean about wait for the puddle and then stab filler. I've watched several hours of guys doing it on youtube. The problem is that I never get a puddle to stab. Also it's melting the piece within 3 seconds.

If I had to guess, it has something to do with I'm not getting thru the oxide layer before the metal underneath melts away. However I tried going up to 50% cleaning and it didn't help. I'm also getting black soot in the area I hold the arc. When the filler melts it goes into little black gobs that won't adhere to the workpiece.

[Deep Six]

Actually I was trying to add filler in the aluminum
Using 3/32" 4043 filler, a full 1/2" off the end of the filler rod would melt before I got within a 1/4 inch of the tungsten though. Like I said, the arc was so huge and unfocused, there was no way to pinpoint the heat and it was just just pretty much melting everything within a 1/2 inch of the tungsten.

The aluminum I was using was just hardware store stock like you get at Home Depot.

Also I should add that the welder works great with stick. I'd only ever used an old Lincoln a/c buzz box for stick and this DC inverter machine makes a world of difference.

[christian]

Yeah,

It's probably bad gas then.

Rarer is a faulty regulator, I suppose, too.

Please let us all know if a fresh tank of Argon does solve your problem.

[Deep Six]

He thought the arc sounded good. By cathodic etching do you mean the infamous "cleaning action"? If that's what you mean, my answer would be "kind of", not nearly to the extent I see in youtube videos of the process.

Tungsten is 3/32" lanthanated 2%. #7 gas lens, argon at 20 cfh. Tungsten is balled and clean after welding. Tried grinding it to a point, leaving it squared off, and everything in-between. Result after welding is a blunted, small ball and clean either way.

[christian]

Yeah,

20 CFM is a tad of high, but not enough to be causing your problem. I'd drop it down to 15 anyway, especially if you're using a gas lens.

You probably won't see the etching if dwelling in one place without a tight arc, or until there's a puddle and you start moving.

If you hold a tight arc and move the torch along the top of the metal, you can see it that way, as it can give some preliminary cleaning action and preheating for a weldiing bead or seam. But it's not a typical thing to do.

Some pics of your torch, with tungsten prepped, and showing the stick-out might help us spot something, too.

Originally, were you welding on some galvanized, ground-off?

That might have been your initial problem with porosity on steel.

Otherwise, I'm guessing that you're on the brink of similarly turning for the better with aluminum.

"Three seconds" or less, watch for the "glint", stick it, then pull back the filler. That's a tack on aluminum. And a bead is a series of tacks, so to speaks.

But you gotta see it first!

He thought the arc sounded good. By cathodic etching do you mean the infamous "cleaning action"? If that's what you mean, my answer would be "kind of", not nearly to the extent I see in youtube videos of the process.

Tungsten is 3/32" lanthanated 2%. #7 gas lens, argon at 20 cfh. Tungsten is balled and clean after welding. Tried grinding it to a point, leaving it squared off, and everything in-between. Result after welding is a blunted, small ball and clean either way.

[Rambozo]

He thought the arc sounded good. By cathodic etching do you mean the infamous "cleaning action"? If that's what you mean, my answer would be "kind of", not nearly to the extent I see in youtube videos of the process.

Tungsten is 3/32" lanthanated 2%. #7 gas lens, argon at 20 cfh. Tungsten is balled and clean after welding. Tried grinding it to a point, leaving it squared off, and everything in-between. Result after welding is a blunted, small ball and clean either way.

Sounds like you have covered all the bases. Nothing jumps out as a problem. On the off chance it is a balance issue, try a weld with the balance set to 75%+. Expect the tungsten to melt into a big ball, if it doesn't something is off with the balancing.

As far as having the filler not melt when introducing it , that takes some practice. Torch angle , arc length, rod angle, and speed all play a part. One thing you don't want to do is pull the rod way out between dabs. You want it to be out of the heat but stay within the argon envelope, so it doesn't oxidize. Also make sure your rod is clean. A wipe down with acetone is always a good idea. For 1/8" material bead on plate, I would use 1/16" filler. 3/32" at the most. Keep your torch at 90° and move your head instead, to see around the torch. Aluminum magnifies any lack of proper prep or technique. Steel has to be clean, but aluminum has to be sterile! Especially when you are learning.

One thing because you are seeing soot and have also had issues with steel, is I would make sure your torch isn't sucking in any air. Easier said than done, but checking all the o-rings and sealing surfaces for cuts, roughness, or burrs, especially the back cap and where the cup meets the insulator, is a good start. Maybe your expert can do a leakdown test on it for you.

[Kempy]

How close are you to the welder it might be blowing the gas away from the weld I have see that many a time with Everlast because they blows the air out the front of the machine most Millers and Lincoln blow out the back just a thought.

[christian]

Yeah,

I had an overhead air conditioning vent that would mess with my welding/shielding gas.

[Deep Six]

Ok pictures:

Mess I made (notice how it digs and won't let me build the aluminum up):


Tungsten before:


Tungsten after:

[Deep Six]

Not much of an update, but I managed to stop by the local welding supply house and pick up some different tungstens and filler. Figured I should try that before paying for another tank of gas.

Also, the welder was a good 5 feet away and pointed parallel to the workpiece, so I don't think it was the fan blowing the argon away.

Other than that it's been too cold in my unheated shop to bother with practicing. I'll update this again when it gets warmer lol.

[Deep Six]

Additional info:

I was previously having problems with porosity in ground, clean A36 steel. NOT galvanized anything. I solved the porosity issue by using stainless 309 filler. I was also having some success using going slow and jamming as much ER70S2 filler as I could manage into the weld. However even the steel welds have a dull grey appearance that can be wire brushed to a nice shine.

I did try cleaning settings between 20 - 80%. 20% gave me more black goo and 80% gave me a giant ball on the tungsten and no penetration, as expected.

I think I'm better than halfway thru the 55cf tank of gas. So soon enough I'll have a fresh tank of gas to try.

[performance]

Those show evidence of contamination. Definitely looks like bad gas. If your tungsten is balling, it should not be an issue with AC.

[Rambozo]

Additional info:

I was previously having problems with porosity in ground, clean A36 steel. NOT galvanized anything. I solved the porosity issue by using stainless 309 filler. I was also having some success using going slow and jamming as much ER70S2 filler as I could manage into the weld. However even the steel welds have a dull grey appearance that can be wire brushed to a nice shine.

I did try cleaning settings between 20 - 80%. 20% gave me more black goo and 80% gave me a giant ball on the tungsten and no penetration, as expected.

I think I'm better than halfway thru the 55cf tank of gas. So soon enough I'll have a fresh tank of gas to try.

Ok, I just wanted to make sure your balance control was working properly. Check, that is as expected.

For learning I would advise larger pieces of material, that way the heat won't get out of control so easily. Also cool off the material between welds. For practice you can just dunk them in water, but don't do that with actual projects. Also ensure that it is totally dry before trying another bead. From what I can see your arc length looks to be on the large side. Rule of thumb, try to hold a max arc length about one tungsten diameter. To do this you will have to lift the torch as you add filler then lower it as you move forward. Trying to jump right into aluminum is a big challenge. When I have taught new employees to TIG, I typically start with 1/8" steel then wait until they semi master that before moving to 16 gauge sheet steel. Where upon the welds go back to looking like crap but they get that pretty quick. Once they master the sheet metal and start getting cocky. I bust out the 1/8 aluminum and take them down a peg or two. Their welds go back to looking like crap, but they understand the fundamentals and have a pretty good idea what they are doing wrong, just not enough control to prevent it. That just takes practice. However, everything you learn about aluminum will make steel a cake walk. Once you can lay a good bead on 6061, you can weld steel standing on your head. Previous MIG and stick welding skills never made much of a difference. If anything they had bad habits from other processes. The only person I taught that got it quickly was someone that had done a bunch of oxy-fuel welding many years before. And while watching videos is a great new way to learn, it probably won't be as fast as someone looking over your shoulder, saying more pedal, less pedal, too long, don't starve the puddle, add filler, get moving, etc. It just takes practice.

[Deep Six]

Well it warmed up a little so I got back out there and practiced some more. Tried my new purple tungstens and new ER70S2 filler. Neither helped anything. Still getting that bad herringbone porosity.

I did, however, have some luck using stainless 308 filler on A36 steel. Does this look like everything is working right? The welds still look a little "frosted" to me compared to other tig welds I've seen...

[performance]

Are you in DC or AC on this one? What is thickness and amps? Tungsten? Torch still in negative?

[Deep Six]

That picture was DC electrode negative 100 amps. That was a piece of 1/8"x2" A36 steel. 3/32" tungsten and 1/16" stainless 308 filler.

I did also try AC on steel this time and got pretty much the same result I did on the aluminum: arc just went everywhere and I couldn't form a puddle.

[christian]

Yeah,

Your beads on steel look OK and are now free of the earlier porosity. So, you undoubtedly either squared away your gas, or you're now using better base metal, or you're cleaning the metal better before welding, or your earlier filler rod was dirty somehow.

Don't do AC on steel. DCEN.

Go back to the aluminum now.

Put some new beads on plate and show us where you're at with them.