[DougW]

Can't figure this out... New to Tig welding. Been at it 8-10 hours a day for the last week. I'm getting "better" simply because I had no where to go but up! Here's my problem - or at least one of my problems.

I've practiced on 1" x .125" angle, 3" x .125" flat stock and 1.750" square tubing. A project I want to build is driving the need to learn to tig. The learning curve is going OK on the angle stock and flat stock. Still going too slow and getting too hot but practice, I hope, will eliminate those problems. Of course I struggle with feeding filler rod but getting marginally better there as well. With the 1.750" square tubing I'm taking 2 - 4" pieces and forming a tee. This leaves me with 2 butt joints and 2 fillet joints. I'm having extreme difficulty starting the first butt weld. It simply will not pool on a regular consistent basis.

Tig welder is a HTP Invertig 221. Initial settings were 125 amps, 125 Freq., 65% EN, and 15 CFH Argon. Electrode is an 3/32" purple/E3 and the cup is a standard #6 ceramic(pink). As stated I can not get this first weld to pool. It gets contaminated, the filler rod gets contaminated. Every great once in awhile I can get it to pool and can run the first bead. Once that first butt joint is welded I'm off to the races. I flip it over and weld the second butt joint. Pools easily runs just fine until I decide it'd be stronger if I added some tungsten or I pull the filler rod out of the argon envelope.

I tried:
150 amp
125 freq
65en balance
15 CFH

Actually I tried a lot of settings and thought I had hit on the best one coming in at:
150 amp
150 freq
65%en balance
I'm set up for .3 sec. pre-flow and 4 sec. post-flow

Those settings worked once. Then back to the same problem.

Prep includes cleaning part with acetone and SS wire brush(in one direction). I clamp the two pieces together. I can tack this first butt joint on a fairly regular basis but even the tack looks contaminated(dull grey).

I've tried hitting it with 150 amp until you'd swear it would cave in but it doesn't - doesn't pool either!

Tried lowering the frequency to ~100-110. Made a wider cone but didn't solve the problem.

I've tried pre-heating with a propane torch. That did not help. Maybe I didn't get it hot enough?

So that's where I'm at. Once that first joint is cobbled together the other three joints pool up just fine and suffer only from inexperience behind the torch.

Thanks!

[v5cvbb]

Did you mention metal type? Are you welding aluminum?

Are both parts getting a good ground? That's important until they are together.

[cj737]

Did you mention metal type? Are you welding aluminum?

Are both parts getting a good ground? That's important until they are together.

If you look at his settings, its obviously aluminum.

[cj737]

Even with .125 thickness, 150 amps should get you a puddle, especially if you are preheating. Sounds mostly like a long arc situation.

Personally, I'd up the amps to 180, 120Hz, 65% Balance, and use your pre-flow. Mash the pedal. Focus the arc on one side or the other until it starts to wet, move the arc to the adjacent piece and get your puddle. Then arc to the root, add filler. A contaminated filler rod is a key giveaway that you're long-arcing.

Tight arc means tip of tungsten equal distance to the material as the filler rod. Or just a hair longer to avoid dipping.

[DougW]

Thanks for the reply!

I can only "assume" both parts are getting a ground. They are solidly clamped together. Both pieces have been cleaned to the the point it suggest I may have an OCD. Cut on a horizontal bandsaw using water soluble coolant. Rinsed with water. Blown dry. Wiped w/acetone. Edges filed. Faces wire brushed in one direction. Assembled w/clamp.

Yes, It's aluminum.

I was using an extremely sharp, 15 degree, electrode w/o balling. Electrode stick-out was ~5/16".

I have since started balling the electrode and reduced the stick-out to ~3/16". Those two changes "seemed" to have helped but it still ain't easy starting the first joint. I may miss the point it starts pooling and end up over heating - could that cause the problem I'm seeing? I could be that's it pooling extremely quick. The only got'cha' with that theory is the fact the other 3 joints I don't have problems with....

[Spartan]

Did you mention metal type? Are you welding aluminum?

Are both parts getting a good ground? That's important until they are together.

If you look at his settings, its obviously aluminum.

I don't think any assumptions can be too obvious when someone says they are new to TIG welding and having problems. That was a legit question, IMO

[cj737]

Did you mention metal type? Are you welding aluminum?

Are both parts getting a good ground? That's important until they are together.

If you look at his settings, its obviously aluminum.

I don't think any assumptions can be too obvious when someone says they are new to TIG welding and having problems. That was a legit question, IMO

The ground questions, sure. But TIG welding with AC Balance and frequency parameters? Can only be an alloy.

[DougW]

Even with .125 thickness, 150 amps should get you a puddle, especially if you are preheating. Sounds mostly like a long arc situation.

Personally, I'd up the amps to 180, 120Hz, 65% Balance, and use your pre-flow. Mash the pedal. Focus the arc on one side or the other until it starts to wet, move the arc to the adjacent piece and get your puddle. Then arc to the root, add filler. A contaminated filler rod is a key giveaway that you're long-arcing.

Tight arc means tip of tungsten equal distance to the material as the filler rod. Or just a hair longer to avoid dipping.

I did what's highlighted in blue. But then... I tried to get the two sides to flow together before adding filler. Hence getting stuff a tad hot. Long arcing is a possibility as is too much torch tilt. But... I only have problems on this first butt joint everything else is fine. And that is what has me scratchin' my head!

Current settings are now
125 amp
130 freq
75%en Balance
15 CFH argon
Pre .4
Post 4.0

I will be implementing the settings you suggested here shortly.
Thanks for the help!!!

[DougW]

Bingo! We have a winner!!!

The new, and improved, settings seemed to do the trick. Followed the procedure --> one edge pool... the other edge pool... and get to feeding filler. Thanks for getting me straight on that. Been battling that issue for 4 days!

[v5cvbb]

He said he was new to Tig welding, so it never hurts to ask the obvious.

My first days Tig welding, which was less than a year ago, I found aluminum easier than steel because I could actually see the puddle better. I can't imagine you are missing it. No idea what effect the extreme sharp tungsten grind has as use less steep and normally blunt.

Just trying to think back to my problems starting out. Glad they got you sorted.

[Oscar]

Just FYI. Testing using spot-tacks. 16 gauge, outside corner. About 40° tungsten grind angle. 2mm arc length.




AC Freq plays a good part. Inside corners need the most help. Crank it up to 200 Hz and let 'er rip. The more EN balance you can run, the better, but not as affective as a higher Freq, IMO.

[Spartan]

The ground questions, sure. But TIG welding with AC Balance and frequency parameters? Can only be an alloy.

I'm with ya. Perhaps my habit of rejecting "obvious" assumptions is from too many years of training 18 year olds in the military

[DougW]

Mmmmm.... The problem returned. At some point between then and now I was resting my arm on the table and started noticing I was getting a light shock/tingling from making contact with the table. Because poor grounding was mentioned I started chasing that puppy. The symptoms created by poor grounding are virtually identical to the problem I'm having. Poor starting. I mentioned that I was hitting the pieces with 150 amp, on 1.75" x .125" square tubing and it simply would not melt, would not pool - seemingly no matter how long I held the arc in one spot.

I'm welding on a Harbor Freight welding table - which "should" be fine. I took a flapper wheel on a side grinder and cleaned up the table top so that should be good. There is/was a problem attaching the grounding clamp as this table has painted edges that can be raised/lowered and a good part of the clamping force is on that painted edge. Yesterday I welded a piece of 1" x .250" flat bar to the table to attach the grounding clamp to. That didn't help.

One thing I did do several days ago was put a piece of aluminum plate on the table top then put my work pieces on top of that. I'm thinking that may be part of the problem. This plate is not secured to the table and moves around rather easily. Yesterday I used the grounding clamp to clamp that plate to the table and still had the same problem. I still suspect I'm dealing with a poor ground issue and plan to put welding clamps on the work piece and then ground to the clamp and see how that preforms!

[Poland308]

Mmmmm.... The problem returned. At some point between then and now I was resting my arm on the table and started noticing I was getting a light shock/tingling from making contact with the table. Because poor grounding was mentioned I started chasing that puppy. The symptoms created by poor grounding are virtually identical to the problem I'm having. Poor starting. I mentioned that I was hitting the pieces with 150 amp, on 1.75" x .125" square tubing and it simply would not melt, would not pool - seemingly no matter how long I held the arc in one spot.

I'm welding on a Harbor Freight welding table - which "should" be fine. I took a flapper wheel on a side grinder and cleaned up the table top so that should be good. There is/was a problem attaching the grounding clamp as this table has painted edges that can be raised/lowered and a good part of the clamping force is on that painted edge. Yesterday I welded a piece of 1" x .250" flat bar to the table to attach the grounding clamp to. That didn't help.

One thing I did do several days ago was put a piece of aluminum plate on the table top then put my work pieces on top of that. I'm thinking that may be part of the problem. This plate is not secured to the table and moves around rather easily. Yesterday I used the grounding clamp to clamp that plate to the table and still had the same problem. I still suspect I'm dealing with a poor ground issue and plan to put welding clamps on the work piece and then ground to the clamp and see how that preforms!

The shock is from arcing on your filler rod and not the metal.

[DougW]

The shock is from arcing on your filler rod and not the metal.

Thanks for that bit of info...

Actually I have finally figured out what the problem is! I suck at cold starting 1.75" x .125" square tubing!!!

It is not a ground issue - if it ever was.

It is not a "dirty metal" issue. Acetone, file on edges, SS wire bush(only ever used on aluminum) all surfaces

Might be a pre-heat problem as I tried running the arc up and down the first joint hoping to heat things up. That still did not solve the hard starting problem. Getting a pool is a problem. Once I get past that first joint be it butt or inside corner it goes good.

While you can see the upper and lower welds on these test pieces my focus and comments are relative to the weld in the middle.

The right hand side is where I started. This is after running the arc up/down the inside corner joint.

For those that don't know... You can double-click on the photo which takes you my flicker site and enlarge/zoom on any of these photos...



Obviously I'm still dipping, touching the electrode with the filler rod and pulling the filler rod out of the argon envelope but I'm getting better. Next I'm gonna try pre-heating the dookie out of it and see what happens

[Oscar]

You dont need pre-heating on 1/8" alum. You have plenty of power, you just need to apply it.

You need to:

Crank the machine up to 170A or so.
hold a tight arc (no more than 2mm)
with very little torch angle (<10°)
you likely are ramping up too slowly which is not all that great for aluminum
you need to run a high AC freq (>120Hz)
and finally with as much EN balance as that material can tolerate without getting a lot of "pepper".

I havent TIG'd 1/8" aluminum lately, but I remember thise settings working really well previously. Give me a couple hours and I can demonstrate.

[DougW]

Thanks! Again...

The machine settings used for the above photos.

Amp - 180
Freq. - 200
EN - 70
Argon 15 CFH

The arc is as close as I can get it w/o touching - most of the time.
Torch angle is pretty much perpendicular (filler rod almost parallel to joint while maintaining 90 degrees between filler rod and torch.

Ramping up - That could be a problem but I 'think' I'm nailing it but I may back off too soon for fear of blowing through the material.

The material is crazy clean. I have tried 75en I'll bump it up to 80-85 and see what transpires!

Again... I only have this problem on the first weld on square tubing. This problem does not exist for me on 3" x 1/8" flat stock nor does it exist on 1" x 1/8" angle. Nor do I have this problem after the first weld on square tubing. The second weld pools like "RIGHT NOW".

I do appreciate the help and advice! Lord knows I need it!

[Oscar]

Thanks! Again...

The machine settings used for the above photos.

Amp - 180
Freq. - 200
EN - 70
Argon 15 CFH

The arc is as close as I can get it w/o touching - most of the time.
Torch angle is pretty much perpendicular (filler rod almost parallel to joint while maintaining 90 degrees between filler rod and torch.

Ramping up - That could be a problem but I 'think' I'm nailing it but I may back off too soon for fear of blowing through the material.

The material is crazy clean. I have tried 75en I'll bump it up to 80-85 and see what transpires!

Again... I only have this problem on the first weld on square tubing. This problem does not exist for me on 3" x 1/8" flat stock nor does it exist on 1" x 1/8" angle. Nor do I have this problem after the first weld on square tubing. The second weld pools like "RIGHT NOW".

I do appreciate the help and advice! Lord knows I need it!

those settings would work just fine. What ever the issue is, it's simply something you are omitting because you are not noticing it as part of the learning curve. Or it could be the ramp-up like you mentioned. I prefer to puddle it quickly. Less than 2 seconds. One-one-thousand-two, and I'm off! From your description it sounds like the torch angle and arc length are under control. I can't imagine you NOT getting a puddle unless you are just baby'ing it and only using 30A at the beginning, or you have a really wrong tungsten grind angle on your tungsten.

[DougW]

Not doubt you're correct - something I'm missing. Best I can describe is on the first weld hitting it at 180 amps it takes 3 seconds for the following to appear. At this point I'm not even holding a filler rod I'm just trying to figure out when it starts to pool....

A little history first. This had been my welding set up. Aluminum plate on Harbor Freight welding table. Pieces not clamped.

20200515_085459 by Doug Wei, on Flickr

This is now... I removed the aluminum plate, clamped the pieces together on the table.
20200515_140219 by Doug Wei, on Flickr

This is the results of 180 amp / 200 freq / 75 balance/ 15 CFH argon @ 3 seconds
My cheap o'l temp gun showed the pieces ~160 degrees

20200515_140318 by Doug Wei, on Flickr

Then I run a short bead but it really isn't going down easy nor pretty... I'm not doing a good job of feeding filler.

20200515_140442 by Doug Wei, on Flickr

Then I complete the weld on that joint - I come back and close up all the corners after everything else is done.

20200515_141129 by Doug Wei, on Flickr

Then I weld the other 3 sides. The welds aren't much to look at as I'm struggling to keep the filler rod in the envelope and out of the electrode. Some days have been better than others as far as dipping and moving.

20200515_141352 by Doug Wei, on Flickr

20200515_141640 by Doug Wei, on Flickr

20200515_141645 by Doug Wei, on Flickr


Here's some of my better welds over the last few days...

20200515_144018 by Doug Wei, on Flickr

20200515_144004 by Doug Wei, on Flickr

20200515_143958 by Doug Wei, on Flickr

20200515_143948 by Doug Wei, on Flickr

[Oscar]

This is the results of 180 amp / 200 freq / 75 balance/ 15 CFH argon @ 3 seconds
My cheap o'l temp gun showed the pieces ~160 degrees

20200515_140318 by Doug Wei, on Flickr

That just doesn't seem right to me. The few times I TIG'd 1/8", I'm 99.9% positive it did just fine with that similar level amperage on the same exact machine. Are you saying you completely mashed the pedal all the way down, at 180A, and you obtained that small puddle that took 3 seconds (roughly)?

I actually got swamped with work today, so I won't be able to recreate a similar joint until tomorrow.

In the meantime, can you hold your tig torch in the same exact orientation with the same exact distance you are keeping the tungsten from the joint? Please indicate what size tungsten you are using/in the picture.

Also, have you changed the independent amplitude settings on the machine?

Since you only have an air-cooled torch. I suspect that is the reason you have not attempted higher amperage(?)

[cj737]

The higher the frequency, the less penetration. Lower the frequency to 60-90Hz, whatever you want.

I still suspect you are long arcing (why the point was raised about holding torch etc.). At 180 Amps, full pedal, you should be turning the backside of the aluminum to molten. Unless you're long arcing...

[Oscar]

The higher the frequency, the less penetration. Lower the frequency to 60-90Hz, whatever you want.

I agree, but even at 200Hz, it should still be able to punch through regardless.

[cj737]

The higher the frequency, the less penetration. Lower the frequency to 60-90Hz, whatever you want.

I agree, but even at 200Hz, it should still be able to punch through regardless.

Completely agree. Look at the picture with his "spot". Notice how wide and diffused the etch line is? If that's at 200Hz, he's about 5/8" for arc length All of his fillet beads show a too wide etch for 200Hz in my opinion. With my Dynasty (and I'm certain with an HTP) the etch at 150 or > is so tight to the bead that you can barely tell its welded. (If you have proper arc length).

[Oscar]

I don't think it's that narrow on the HTP 221. It's still visible, but not quite how you describe it. I'll try it out tomorrow. Just received some scrap so it's perfect timing.

[Spartan]

What waveform is being used? Does that HTP offer options on that?