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How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 5:50 pm
by Chips O'Toole
I decided to start practicing with 1/8" aluminum because it's easier to prepare than steel. It made a big difference and allowed me to spend a lot more time welding. Now I have questions.

1. Sometimes the arc just will not start. If I move the torch from a place where it won't start, I can find a place where it will start. What's up with that?

2. I was trying to do lap welds, and the arc absolutely refuses to stay put. I want it down in the joint, but it bounces between the flat piece and the upper corner of the upper piece. How do I make it stay in the joint? I was chasing the puddle all over the place.

I found some suggested settings, and that's what I used. I was at around 140 amps (with the pedal) and 25% AC balance. I started at 75 Hz, but I read somewhere that increasing the frequency would make it easier to aim the arc, so I tried again at 125, and things seemed better (but still bad). I used a 3/32" E3 tungsten.

The first time I welded, I used aluminum pieces that had been wiped down but not cleaned in any other way. The second time, I polished them with sandpaper and followed with acetone. Didn't seem to matter.

Welding flat beads on top of the pieces seemed about like welding steel, except that I had to move fast to keep the metal from melting too much.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 6:13 pm
by Farmwelding
If your arc is wandering it may be the tungsten sharpening. As for the arc not starting, I have that happen all the time while I practice and usually i end up scratching it like a scratch start rig which isn't a good idea idea due to arc strikes. It may be due to poor ground, or maybe try cleaning the aluminum more with a stainless wire brush and acetone. Sometimes it helps.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 6:18 pm
by Otto Nobedder
Mash that pedal. Don't be shy and sneak up on it. The arc will only focus when you put power behind it. It will still want to wander from one piece to the other, but if you hit it fast and hard, you won't wonder where it's going. Manipulate the torch back and forth across this phenomenon until you see molten metal tight in the corner, and add your first bit of rod.
Once you add rod and tie the two sides together, everything gets easier, as the arc will find the puddle, not the sides. This is where what I said about advancing to the front of the puddle and waiting for it to follow you before adding more rod comes in to play.

Steve S

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 6:19 pm
by Chips O'Toole
Should I be welding with a balled up tungsten? Some Youtube dude says he fries his tungstens with DC to ball them up before doing aluminum. I was just putting about a 3/16"-long point on it with the belt grinder.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 6:23 pm
by Otto Nobedder
Your tungsten will ball all by itself. Only in critical code welds do I ball it first, and then I just use normal settings on some scrap. If you have scrap at hand, that whole "DCEP to ball" thing is wasted time. I grind a short taper, and blunt the point, and call it good.

Steve S

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 7:06 pm
by Farmwelding
Otto Nobedder wrote:Your tungsten will ball all by itself. Only in critical code welds do I ball it first, and then I just use normal settings on some scrap. If you have scrap at hand, that whole "DCEP to ball" thing is wasted time. I grind a short taper, and blunt the point, and call it good.

Steve S
See I don't get this. I've welded a decent chunk of aluminum for the years I've been on this earth( all 17) and I've only used 3/32" ceriated because that's what my school has. I've run from 60-180 amps and never once had it balled. Hell it barely loses its point at 180 amps. The only time my tungsten changes is when I dip-which I don't do as much now. Although the guy Im teaching had a ball on the end of his tungsten the other day that a pen cap couldn't go over. Stabbed it constantly with stainless rod and couldn't figure why his plate wasn't melting and his arc was wandering.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 7:18 pm
by Chips O'Toole
Okay, I'M GOING BACK IN!

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 10:40 pm
by MinnesotaDave
Farmwelding wrote:
Otto Nobedder wrote:Your tungsten will ball all by itself. Only in critical code welds do I ball it first, and then I just use normal settings on some scrap. If you have scrap at hand, that whole "DCEP to ball" thing is wasted time. I grind a short taper, and blunt the point, and call it good.

Steve S
See I don't get this. I've welded a decent chunk of aluminum for the years I've been on this earth( all 17) and I've only used 3/32" ceriated because that's what my school has. I've run from 60-180 amps and never once had it balled. Hell it barely loses its point at 180 amps. The only time my tungsten changes is when I dip-which I don't do as much now. Although the guy Im teaching had a ball on the end of his tungsten the other day that a pen cap couldn't go over. Stabbed it constantly with stainless rod and couldn't figure why his plate wasn't melting and his arc was wandering.
Just listen to Steve (Otto), don't argue with him.
Your machine is running enough negative balance that it doesn't ball - and 180 amps is very small besides.
On a 50/50 machine like my Airco, 1/8" pure balls up right away and welds very well like that.
1/8" thoriated takes longer to ball, but won't always ball smooth.

For the OP, more amps (170-180), full pedal immediately, the arc will straighten out - reduce after you start welding as needed.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 10:42 pm
by Oscar
Chips O'Toole wrote:Should I be welding with a balled up tungsten? Some Youtube dude says he fries his tungstens with DC to ball them up before doing aluminum. I was just putting about a 3/16"-long point on it with the belt grinder.
There's this one Youtube channel that gives really good advice with regards to anything and everything regarding this thread. Look for a channel called weldingtipsandtricks, and some dude that makes those videos gives pretty darn good advice. ;) :D

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 10:42 pm
by MinnesotaDave
Oscar wrote:
Chips O'Toole wrote:Should I be welding with a balled up tungsten? Some Youtube dude says he fries his tungstens with DC to ball them up before doing aluminum. I was just putting about a 3/16"-long point on it with the belt grinder.
There's this one Youtube channel that gives really good advice with regards to anything and everything regarding this thread. Look for a channel called weldingtipsandtricks, and some dude that makes those videos gives pretty darn good advice. ;) :D
LOL!!

I've heard of the guy too :D

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sat Apr 29, 2017 10:50 pm
by Farmwelding
MinnesotaDave wrote:
Farmwelding wrote:
Otto Nobedder wrote:Your tungsten will ball all by itself. Only in critical code welds do I ball it first, and then I just use normal settings on some scrap. If you have scrap at hand, that whole "DCEP to ball" thing is wasted time. I grind a short taper, and blunt the point, and call it good.

Steve S
See I don't get this. I've welded a decent chunk of aluminum for the years I've been on this earth( all 17) and I've only used 3/32" ceriated because that's what my school has. I've run from 60-180 amps and never once had it balled. Hell it barely loses its point at 180 amps. The only time my tungsten changes is when I dip-which I don't do as much now. Although the guy Im teaching had a ball on the end of his tungsten the other day that a pen cap couldn't go over. Stabbed it constantly with stainless rod and couldn't figure why his plate wasn't melting and his arc was wandering.
Just listen to Steve (Otto), don't argue with him.
Your machine is running enough negative balance that it doesn't ball - and 180 amps is very small besides.
On a 50/50 machine like my Airco, 1/8" pure balls up right away and welds very well like that.
1/8" thoriated takes longer to ball, but won't always ball smooth.

For the OP, more amps (170-180), full pedal immediately, the arc will straighten out - reduce after you start welding as needed.
Yeah I've kind of figured that out. When Steve says something just go with it. He's got my respect from all the crao he's done. Many others here too but...

Although I thought 180 amps was real heavy on AC current for 3/32"

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 2:59 am
by Otto Nobedder
180 IS heavy amps for a 3/32 tungsten, but I usually try for clean enough to set the balance at 10 (max penetration), which allows a lot of amps. I have 1/8 pure tungsten, but didn't switch to it for my recent project welding about 1/4" (Actually, schedule 40 and some 1/4" plate. If you see the ball quiver, you're too hot for the tungsten size and it could puke into your weld.

One of these days, I'll get to use a high quality inverter machine again, and will be able to use the Lanthanated tungsten everyone raves about.

Steve S

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 8:42 am
by MinnesotaDave
Farmwelding wrote: Although I thought 180 amps was real heavy on AC current for 3/32"
Not for the ceriated tungsten you're using with the diversion tig.

Since it runs better balance than the 50/50 of old machines, you're on a different part of the chart.
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Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 12:30 pm
by Otto Nobedder
Good info, Dave, thanks for the chart. It seems to show the limit for 3/32 pure at 160A at 70% EN, but I think "10" on my synchrowave is 80% EN which is why I was able to stay within the limits and not dig out my 1/8" stuff. I was set at 225A, but only used that to initiate the puddle, backing off as the heat built up. Of course, those pictures are on another thread...

Steve S

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 1:11 pm
by MinnesotaDave
80% is pretty darn good - my old Syncro 350 that I picked up only goes to 68%

I wonder what the upper limit is for "just enough" cleaning?

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 2:01 pm
by Chips O'Toole
I am working to apply the advice I'm getting. The welds are still hideous, but now they ARE welds.

My rod-feeding is pretty lame, and it seems to cause more problems with aluminum, because if you screw up, the weld goes nuts while you're trying to get your left hand straightened out.

I decided to order some lanthanated tungstens, because my belief is that skill is no substitute for buying new tools.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 2:11 pm
by MinnesotaDave
Chips O'Toole wrote:I am working to apply the advice I'm getting. The welds are still hideous, but now they ARE welds.

My rod-feeding is pretty lame, and it seems to cause more problems with aluminum, because if you screw up, the weld goes nuts while you're trying to get your left hand straightened out.

I decided to order some lanthanated tungstens, because my belief is that skill is no substitute for buying new tools.
Make a flat pad of beads, half overlap every prior bead so the top ends up flat.
Use 1/8" thick and at least 8" x 8" so it's big enough to not overheat on every bead.

Once you finish a few of those, your feeding hand should be much better.

Skill and practice wins over buying tools any day :D
After about 100 hours it all gets easier.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 2:16 pm
by Farmwelding
MinnesotaDave wrote:
Chips O'Toole wrote:I am working to apply the advice I'm getting. The welds are still hideous, but now they ARE welds.

My rod-feeding is pretty lame, and it seems to cause more problems with aluminum, because if you screw up, the weld goes nuts while you're trying to get your left hand straightened out.

I decided to order some lanthanated tungstens, because my belief is that skill is no substitute for buying new tools.
Make a flat pad of beads, half overlap every prior bead so the top ends up flat.
Use 1/8" thick and at least 8" x 8" so it's big enough to not overheat on every bead.

Once you finish a few of those, your feeding hand should be much better.

Skill and practice wins over buying tools any day :D
After about 100 hours it all gets easier.
Yep... Pad beads all day long and you will start to worry about the puddle rather than feeding wire. And as Johnny Cash once sang-Get rythm. Find that pulse that gets you going. Try music or a metronome. It helped me when I was starting. Balance the puddle and dipping rod win the pulse of some good ole country.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Sun Apr 30, 2017 2:48 pm
by Otto Nobedder
Y'know what's crazy? I can weld well with either hand, but I only recently realized that when the torch is in my left hand, I can't feed rod worth a damn with my right. That's messed up!

Steve

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Mon May 01, 2017 5:35 pm
by Chips O'Toole
I decided to see if lanthanated tungsten was any more friendly than E3. I have a feeling the problem will still boil down to a total lack of skill on my part.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Mon May 01, 2017 5:48 pm
by exnailpounder
Chips O'Toole wrote:I decided to see if lanthanated tungsten was any more friendly than E3. I have a feeling the problem will still boil down to a total lack of skill on my part.
When I started playing guitar, I thought better guitars would make me play better. Seat time is the only way...lot's of it too

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Mon May 01, 2017 7:26 pm
by MinnesotaDave
Chips O'Toole wrote:I decided to see if lanthanated tungsten was any more friendly than E3. I have a feeling the problem will still boil down to a total lack of skill on my part.
You're actually changing the least significant thing when switching those two tungstens.

In my opinion.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Tue May 02, 2017 12:15 pm
by Chips O'Toole
MinnesotaDave wrote:You're actually changing the least significant thing when switching those two tungstens.

In my opinion.
Best I can do. If I changed the part that's causing most of the problems, someone else would be using my welder.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Tue May 02, 2017 2:49 pm
by MarkL
Chips O'Toole wrote: If I changed the part that's causing most of the problems, someone else would be using my welder.
Now that's funny.
I had been using zirconiated tungsten on a transformer machine and really liked it, switched to an inverter machine and it arced over to the gas lens and everywhere but the aluminum- basically unuseable. Went to a 2% lanthanated and had good luck, also ceriated worked well. I had a bit less luck with E3, it seemed to always run hotter for me and create a wider, dull colored bead, but it was acceptable. I think professional welders can use any tungsten and make it work. For home hobbyists and amateurs, I think trying different things can tip the balance in our favor.

Re: How to Get Arc Into Aluminum Lap Joint?

Posted: Tue May 02, 2017 8:53 pm
by MinnesotaDave
Chips O'Toole wrote:
MinnesotaDave wrote:You're actually changing the least significant thing when switching those two tungstens.

In my opinion.
Best I can do. If I changed the part that's causing most of the problems, someone else would be using my welder.
Ah, the loose nut behind the wrench is more of an issue :lol: