joining copper/brass to aluminum?

[Haywire]

Is there a weld method to join a copper or brass fitting to an aluminum base? I've got a small aluminum radiator that I want to put compression fittings on for copper tube, but I can't find any aluminum compression fittings that I can get tigged on. All the compression fittings are brass or copper.

Ian

 

[zonta223]

Is there a weld method to join a copper or brass fitting to an aluminum base? I've got a small aluminum radiator that I want to put compression fittings on for copper tube, but I can't find any aluminum compression fittings that I can get tigged on. All the compression fittings are brass or copper.

Ian

Not a direct answer to you question.....but when I used to do service on domestic refrigerators I was able to buy aluminum compression fittings that were certified to work and be compatible with both copper and aluminum. check your nearest refrigeration wholesaler

 

[Shield Arc]

aluminum base

Would a bulkhead fitting work?

 

[Baby Grand]

Maybe brazing? Never tried this stuff, but looks promising:

Uniweld UNI-4300 - How to Braze copper to brass to aluminum

 

[AKwelder]

Try Sil-Floss or a similar silver solder product.

 

[Yellowhair42]

You also could try welding an NPT fitting on then you could thread anything into it.

 

[Damifino]

You also could try welding an NPT fitting on then you could thread anything into it. :thumbsup:

Something like this.

 

[yomax4]

The Solders like Al-Solder 500 by harris will do the job but are not very strong. Makes a good good eye catcher at shows but is really limited. We used to solder Stainless to Brass to copper to aluminum in a square and people would buy the stuff although it was weak and fussy. The flux would often burn before the parts were up to temp. I like the aluminum npt idea above.. There are some aluminized copper fittings out there too that solder up. You don't want to use Silver Solder due to the heat it takes to flow out and the aluminum wont like it at all.

 

[Haywire]

That weld on bung fitting might be just the ticket.

Thanks,
Ian

 

[Soundguy]

i've seen plastic ferroules.. but .. I'd try a alloy solder rod first.

I've soldered aluminum to both brass and copper using an alloy rod.

use a clean stainless steel brush.

once the alloy is tinned, you can even silver solder to it.

PS.. most of them alloy rods are high zinc content.. so that tells ya what you can and can't join to. IE.. you CAN solder to galvanized with them rods.. etc.

soundguy