spot welding Aluminum

[Ram48]

Hello
I have a project where I would like to use my tig to spot weld .040 aluminum sheets together, I have been doing that with sheet metal with great success using a home made standoff and the spot timer on my tig machine. any input or suggestions are appreciated
Thanks
Ray

[aametalmaster]

Can you drill the top sheet and plug weld it?...Bob

[Aeronca41]

I once saw a YouTube video by a guy that puts a small pice of steel sheet under each tong point and welds alum. Looked pretty slick. Don't have time to search for it right now.

[aametalmaster]

I once saw a YouTube video by a guy that puts a small pice of steel sheet under each tong point and welds alum. Looked pretty slick. Don't have time to search for it right now.

That's how we did it when i was in the sheet metal shop. But he was looking for TIG welding...Bob

[Aeronca41]

That's how we did it when i was in the sheet metal shop. But he was looking for TIG welding...Bob

Thanks-missed that. Assume the sheet steel trick works pretty well?

[Ram48]

Can you drill the top sheet and plug weld it?...Bob

I can try that if I need to but I am hoping to find some direction on spot welding it.
For sheet metal I made a standoff similar to what eastwood sells and it works perfectly.
I am hoping to find a similar procedure for Aluminum, I am going to try that with the ally in the next day or two on some scrap I guess and see what happens

[aametalmaster]

Thanks-missed that. Assume the sheet steel trick works pretty well?

Yes it did. That was 33 years ago and an old timer showed me it. Now I am the old timer LOL...Bob

[OscarJr]

Lots of focused amperage works great for quick tacks/spot welds.

1/16" 6061

[ryanjones2150]

Correct me if I'm wrong Oscar, but aren't spot welds don't simultaneously from both sides? So not the same as tacking something up I'd say. Without understanding the full aspect of the project, I wonder if drilling a hole a tacking it like that will suffice. Besides, tacks without filler metal are not very strong on aluminum.

[OscarJr]

Correct me if I'm wrong Oscar, but aren't spot welds don't simultaneously from both sides? So not the same as tacking something up I'd say. Without understanding the full aspect of the project, I wonder if drilling a hole a tacking it like that will suffice. Besides, tacks without filler metal are not very strong on aluminum.

You're absolutely right, but if you read the original post, he is already "spot welding" with his TIG and a stand-off and utilizing a spot-timer, so I doubt he is doing true spot welds on sheetmetal from both sides to begin with, unless he has some TIG torch I've never seen that has dual-heads, one for each side of the intended area to be spot-welded. I'm basically answering his question within the context of how it was depicted. Using a standard TIG torch, you can only do one side at a time, which is of course not a true spotweld. My point is not to suggest filler-less spotwelds, only to illustrate that a highly focused arc and higher than normal amperage will get the aluminum melted quickly enough to not drag things out longer than it has to be.

[ryanjones2150]

Ok fair enough. My guess is he gets that part of it. I'd also still say blasting aluminum without filler metal probably isn't going to get the same result as with steel. Without filler metal, Ray, your tacks or spot welds or whatever you want to call them are likely to crack. That's just the nature of aluminum's hot short characteristics. Quick tacks are fine when you're going to come back over them with a weld bead.

[OscarJr]

Yup, you still need to add filler metal if you're gonna be "spotwelding" with your TIG.

[ryanjones2150]

When I was first learning to tig aluminum, I was experimenting on my own and took a small piece of .125 thou aluminum, about 6"x6". Ran a bead down it lengthwise without filler metal to see what would happen. When I got done, you could just about break it in half like a cracker. Kind of neat for someone just starting out. Not that my story helps the OP, just thought I'd throw it out there for conversation purposes.