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]

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.

[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]

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]

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.

[Deep Six]

Christian, you did see that I was using stainless filler for those beads, right? Using the same base metal, same cleaning, same gas, same tungsten, amps, etc with ER70S2 filler (tried two different batches) gives awful porosity like I originally posted. I was thinking the stainless filler merely compensated for whatever is wrong with my setup.

[christian]

Nah,

If you can get a porosity-free bead with stainless filler, then it's not the machine or the gas, as least with DC.

It's probably either the ER70S2 filler, or it's the base metal (partially cleaned galvanized or rust traces) is contaminated.

Sometimes filler can have oil on it. That undoubtedly shows up as porosity, if I recall.

I believe ER70S6 has more deoxidizers in it, which may be helpful if you're attempting to TIG weld on steel that's dirtier somehow.

So, I'd just make absolutely sure that your base metals (steel or aluminum) and your filler rod are perfectly clean and bright down to bare metal.

Show us some new metal prep before-and-after welding.

[performance]

Gray is contamination. You are getting something in somewhere. Also you are probably welding too low of amperage.

[Deep Six]

Any guesses where it might be coming from? Using a new flapper wheel, I've ground the steel to a bright polish then wiped it with acetone, double checked and redid the connections on the gas line, ground the tungsten on a fresh flapper wheel. The only thing left I can think of is a bad tank of gas. I'm going to keep trying stuff before paying for a fresh tank though.

As for amperage, I know the rule is 1 amp per thousandth, and my 1/8" plate would indicate about 125 amps, but at only 2" wide, that much amperage was putting too much heat into the little piece of steel with continuous beads so I turned it down to 100.

[zoama]

Any guesses where it might be coming from? Using a new flapper wheel, I've ground the steel to a bright polish then wiped it with acetone, double checked and redid the connections on the gas line, ground the tungsten on a fresh flapper wheel. The only thing left I can think of is a bad tank of gas. I'm going to keep trying stuff before paying for a fresh tank though.

As for amperage, I know the rule is 1 amp per thousandth, and my 1/8" plate would indicate about 125 amps, but at only 2" wide, that much amperage was putting too much heat into the little piece of steel with continuous beads so I turned it down to 100.

Slow travel speed can put more heat in than turning up the amps and getting it done.

[Deep Six]

Ok time for another update. Yesterday I had a guy from work come over and look at it. This guy spent much of his career in welding so definitely knows his stuff. First off he said there's nothing wrong with my technique. Secondly, he thought the machine was very smooth and worked great on steel. Third, he couldn't get it to work on aluminum any better than I could.

The problem with aluminum seems to be that it's melting the workpiece without ever creating a visible puddle. You just sit there with the arc going waiting for the puddle to appear and then a large section of the piece just slumps off in a gooey slush. Attempting to jab filler in just results in the filler rod evaporating before it gets close to the surface of the workpiece. Again, there's no visible liquid aluminum puddle to work with.

Again, this was on 1/8" thick 6061 aluminum bar, brushed clean, 1/16" 4043 filler, machine in a/c, 120 amps, 100 hz, cleaning dial at 35%, electrode in the - port. The gas is 100% argon that makes for a very steady/smooth arc on steel.

[christian]

Well,

Those effects would most likely be from holding too long of an arc, i.e., you're overheating the aluminum without a pinpointed puddle, then the metal drops out on you.

And, DCEN TIG welding steel without a foot pedal is fairly easy, but not so much on AC with aluminum.

So, as the PT185 is often marketed without a foot pedal included as standard equipment, are you trying to do AC TIG welding on aluminum without a foot pedal?

Or, show us a pic of your torch tip all newly prepped up, and also the aluminum stock before welding or any joint fit-up prep, just to rule-out any chance you're trying to weld on anodized or powder-coated stock.

Aluminum is often very challenging, at first. But once you kind of get onto it, so to speak, it's fun to overcome any of its further challenges, I think.

Hang in there, as you'll undoubtedly get it, then the funner parts start.

[Deep Six]

I did get the optional foot pedal and have been using it.

I could post pictures of the piece, tungsten, etc, but I'm confident I've got it all set up right. This was confirmed by the expert I had out yesterday.

Next step is going to be try welding the same stuff with a different setup. I've got a lead on that and will report back. This will definitively confirm whether the problem is me or my setup.