[Darth]

I am having a terrible time trying to use my new HTP invertig 201 with 1/4 in. aluminum.

I need to weld two plates at an included angle of approximately 80 degrees. I first ground the two plates as shown in "A" and welded the top without pulse or filler rod. I used 3/32 gold tungsten ground to a point and straight Argon gas. The weld looked great, but I discovered it had no penetration. I could easily bend the two parts apart.

Next, I tried leaving the two ends square as shown in "B", figuring the opening would give me full penetration, but I could get a puddle between the two sides.

Next, I tried to weld the inside angle using both pulse and no pulse. The arc wavered all over the place and the tungsten tip balled up. I tried switching to the only 1/8 tungsten I had which was gray, and it still balled up and just globbed up weld, although it made the connection stronger.

I know that I need Argon/Helium mix gas and I have just ordered some 1/8 Lanthiated (S)tungsten.

Part of the problem is that I don't completely understand everything about the Pulse settings. Every article I have found, uses terminology the doesn't quite fit the HTP.

I need help!

welding.JPG (69.63 KiB) Viewed 3272 times

[flyingnunrt]

I'd increase the angle of the vee shown in diagram B to about 45 degrees and leave a small amount at the tip say 2mm and fill that in in 2 or 3 passes then do your fillet on the inside, or do 1 run on outside then do inside fillet then finish the outside.
You sould be able do a reasonable job without pulse at around say 120 - 150 Amps

[metafos]

I agree, increase the angle to 45 degrees, and fill that up. Leave the tungsten about 1/8 inch sticking out for that pass. For the inside pass, reset the tungsten to stick out enough to have it about 1/4 inch from the surface, and do the pass with filler rod, but reduce the current to minimise vibrasion. The part will already be hot enought from the outside pass to make a good weld with less current. You want the tungsten as close to the part as possible for the inside pass, don't worry if it's sticking out too much, it's in a restricted area and the argon will shield it properly.


Georges.

[Darth]

Can I practice this before I get the argon/helium gas, or am I just wasting my time?

[michiganwelder]

Forget the pulser, that won't help you here. Set your machine to balanced AC, running 180-200 amps. Use a 1/8 2% thoriated or lanthanated tungsten. You said you ordered some, so use it. Grey tungsten is manufacturer specified alloys, so it isn't guaranteed to be great for aluminum. Put a #10 cup on your torch and set your shielding gas to 20 cfh. Make sure your metal is clean and of a weldable alloy. By clean, i mean chemically or abrasively cleaned of aluminum oxide. keep your torch at a 45 degree angle to the fillet, and use a 5/32 filler rod. Try that, and you should at least be able to get a decent weld. Good luck.

[metafos]

You can use pure argon .

[brian]

Michigan welder said it best. I'll add in, don't try to fuse that thick of aluminum. It won't hold.

[Darth]

Forget the pulser, that won't help you here. Set your machine to balanced AC, running 180-200 amps. Use a 1/8 2% thoriated or lanthanated tungsten. You said you ordered some, so use it. Grey tungsten is manufacturer specified alloys, so it isn't guaranteed to be great for aluminum. Put a #10 cup on your torch and set your shielding gas to 20 cfh. Make sure your metal is clean and of a weldable alloy. By clean, i mean chemically or abrasively cleaned of aluminum oxide. keep your torch at a 45 degree angle to the fillet, and use a 5/32 filler rod. Try that, and you should at least be able to get a decent weld. Good luck.

Where can I find 5/32 filler rod? I have gobs of 3/32 filler rod, but it just melts before I reach the puddle.

Never mind, I found some.