[JoepWelds]

Hi people of the welding world,

About a year ago I started TIG welding with an old Morellise Weldboy eg251 machine.
Everything I did so far was steel, but a recent project requires aluminum welding. So I thought let’s give it a try.

It’s an old machine so first thing I do is balding the (turquose) tungsten using the inverted poles principle. Then I’m switching to AC, and play a little with the amperage and other settings. I am able to get an arc going and draw a little line, but the result looks really bad. When I’m trying to weld together two pieces it feels like I’m burning away the corners without them melting together. Even at low amperages. (See pictures)

At this point I am wondering wheter Its a settings issue, experience issue, or my transformer is just not doing the trick. Im using 100% argon, 9 liters per minute (19cfh).

Please let me know If you have any suggestions! I will post conclusions when results get better.

Thanks in forward,
Joep

[Bill Beauregard]

You have a dirty tungsten, or a gas coverage issue. You need very clean aluminum. scrub with acetone. Then use a stainless steel brush.

Hit it hard, (Lots of amps) to form a puddle, and bridge. Then, focus the arc on the wet leading edge of your puddle. As you form a "horseshoe" pull your torch back where you came from and dab filler.

[tungstendipper]

I see no cleaning action of the AC.

[Arno]

I see no cleaning action of the AC.

Yup.. No tell-tale white 'etching' along the edges of the weld. Seems like the machine is not outputting AC?

OP: can you hear the 'buzz' of the arc on AC versus welding steel on DC or is there no difference? On 50/60Hz there should be a definite buzz noticeable. (arund 200Hz on an inverter machine gets really skin-crawling annoying though )

Bye, Arno.

[Poleframer]

Does that machine have high frequency?

[JoepWelds]

Thank you very much for the replys.
I got myself a new stainless steel brush and some acetone today.
Everything clean and still gave some of the weird spickles, I turned up the gas to around double the cfh, and that made a big difference.
All looked clean now. When I hit the filler rod, or the Alu with my tungsten I get these black burned spots.
And have to clean the filler rod.

I’m pretty happy with the current results. As the alluminium gets hotter, the puddle gets pretty big.
I have no foot pedal to lower the amperage, so I guess thats kind of what I have to deal with.

When I add very few filler rod the weld sometimes "breaks" (see one of the pictures).
It is solved with adding filler. But is that normal?

Let me know if there are any more tips!

Cheers!
Joep

[tweake]

Thank you very much for the replys.
I got myself a new stainless steel brush and some acetone today.
Everything clean and still gave some of the weird spickles, I turned up the gas to around double the cfh, and that made a big difference.
All looked clean now. When I hit the filler rod, or the Alu with my tungsten I get these black burned spots.
And have to clean the filler rod.

I’m pretty happy with the current results. As the alluminium gets hotter, the puddle gets pretty big.
I have no foot pedal to lower the amperage, so I guess thats kind of what I have to deal with.

When I add very few filler rod the weld sometimes "breaks" (see one of the pictures).
It is solved with adding filler. But is that normal?

Let me know if there are any more tips!

Cheers!
Joep

don't ya just hate dipping the tungsten.

with no pedal you will need to control it by increasing travel speed.

the breaks are "normal" problem caused by the metal cooling. you really need to back off the heat slowly (which you can't do) tho some will stop/start on the end a few times to keep adding a bit of heat to slow down the cooling.
but adding more filler at the end helps stop the crater cracking.
jody has some good video's on this.

you can see why its much easier to have a pedal.

[LtBadd]

When I add very few filler rod the weld sometimes "breaks" (see one of the pictures).
It is solved with adding filler. But is that normal?
Cheers!
Joep

Yes, without adding filler that is normal.