I am correct in saying that you can't weld up holes in used aluminum A/C lines, correct? I'm told it acts like pot metal.

 

This is a really old thread, but since I have an answer to this exact question ... the answer is no way. I tried to repair a pinhole leak on the AC line of my A6 with some of these brazing rods and failed miserably. As soon as you get the area hot enough to melt the brazing alloy the thin wall tube blows out. I tried to do a slip joint type thing with a larger diameter tube as well and that didn't work out either. I ended up spending like $300 at the audi dealer for a stupid piece of tube because I couldn't make this work. (Epoxy, not surprisingly, did not last long.)

 

Hello.....

 

I love how is still has his button up shirt on even under water.

 

Nice timing. I tried it on one of my high pressure lines not too long ago it it worked similarly to yours. I jbwelded a rubber hose around the line in that spot. It is holding fine for now.

 

I've use these rods. Bought them cheap at a hunting show, so I figured to give them a shot. Repaired a severely pitted/erroded (from battery acid) lower end on a Kohler twin 18HP mower engine about 8 years ago, and it has held up well. It leaked oil badly before, and it's all sealed up now.

I used it to weld up hoops from aluminum strips (for wheel rims) and they are impossible to get back apart except by reheating. They haven't seen much use, though.

 

I've used these on my build for intake piping. I used MAPP gas. Worked so-so. Really tough to control the heat so you avoid melting the aluminum. It is a skill -- the connections I made later in the project were much better. Should have practiced more before starting on my actual parts.

It really works well if the aluminum you're working with has some mass to help control the heat. The video examples showed cylinder heads and alternator housings. That would work well. Also works well on cast aluminum outdoor furniture.

One of the video examples showed it being used on a soda can. That's just a skilled operator showing off.

Oh, and just like welding aluminum . . . cleanliness is next to godliness. This stuff hates contamination.

 

mighty tape at walmart is cheaper then silicone tape at the hardware store

 

I ended up using this stuff on a piece of cast aluminum. We could not get it hot enough with mapp gas to get it to work but an acetylene torch did the trick. When we tried to break the joint by hammering on it in a vice the metal broke in a different spot, the brazed part was fine.