Welding Tips and Tricks

Hello everyone, I have purchased some 0.040 aluminum sheet metal a lot of it actually I saved up for the entire summer working to buy this much for a project. I have soldered aluminum before and it wasn't too hard and it worked out well. This time I tried to lap weld one edge flat on-top of another sheet, this didn't work at all. The aluminum would need up and roll away no matter how Long I heated an area I cleaned with a wire brush I tried pre heating the solder slightly. I tried for a few hours an not a drop of solder adhered to the aluminum. I happy to try different types of welding but I don't have a Tig welder and I don't think that would work for this application anyways, thank you to anyone who can help me fix this problem.

If you soldered Aluminum what did you use as a heat source?

Nick.kempel wrote: This time I tried to lap weld .

'Yea, so you don't have a tig welder, yet you tried to make a weld....using what welder?

just having a quick read it seams there is special flux required for thin aluminium.
i suspect whats happening is the thin sheet is overheating before the flux melts.
you could try some backing material to take the heat out of the sheet. common enough trick down with tig welding thin sheet.

are you using a brazing technique with a propane torch ?

https://www.harrisproductsgroup.com/en/ ... 78-22.aspx

I’ve had good luck with this on thin aluminum using just a propane torch. We’ve been able to repair aluminum micro Chanel condensers on hvac units.

Josh, is that the same stuff the peddlers are selling at flea markets and car shows that they demonstrate using a handheld propane torch?

I’m not sure about that. But I was given some by a supply house and I have personally used it for repairs on aluminum condensers for 410A refrigerant. Head pressure can easily be at 350psi and the system is always coated with oil. I’ve also used it on copper to aluminum joints.

With that aluminium solder, there's a few good brands and about a million terrible ones. Look at the price range and do your research based on that.

P.S: Id hazard a guess to say that 0.040 thickness aluminium would be rather problematic to learn on. Get some scrap. 125thou to play with until you get your eye in.

I believe it was the same guy at 2 separate locations I visited--green dragon flea market and carlisle car show--that was demonstrating the stuff by making and closing a hole in the bottom of a pop can. The "weld" was definitely stronger than the base metal and he was having a helluva time dealing with the breeze. He was using MAPP gas in a hand torch.

Jody made a post on his website about fixing the broken hinge of a drop saw with similar stuff. Before he made lots of videos.

The YouTube gods were listening to us. Off to Project Farm we go.... https://youtu.be/fKIKsDfRAcs