Soldering to Aluminum

[invidregis]

Any one out there know how to solder a copper wire to aluminum? Plain old rosin core solder isn't cutting it. I'm guessing a solder with a higher tin content, maybe silver solder? I suppose a special flux is required. Any suggestions would be aprecieated.

 

[taukimada]

i'm far from an expert... but.. last i heard... soldering to aluminum is a no go



my hearing of no such thing as aluminum soldering was from my "soon-to-be ex-"wife.. who does soldering as her means of income...

 

[secondson2929]

I'm afraid that answer is correct. Some other options are interference/press fit or you can use a screw and eyelet to get a connection.

 

[ApOsTle51]

yp . welding aluminium is the same , you needed aluminium welding rods.

Dura Fix Aluminum Welding Aluminum Brazing Aluminum Soldering & Repair Rod

 

[D_Struct]

If this is for making a connection through the casing of a mod, you might be well served by just making sure a wire makes steady contact with the aluminum.

That's all it takes. No solder is necessary.

 

[breakfastchef]

Since you cannot solder to aluminum, you would need to fashion some sort of solid mechanical fastening system to which to attach a conductor.

 

[invidregis]

I'm thinking I will just tap some threads through, put in a small screw and solder to that.

 

[BarryK]

You used to be able to get aluminium and stainless steel soft solder easily in the UK years ago, but I think that the main company selling them went out of business years ago.

The big problem with both is the highly active flux contained in the solder, joints MUST be wiped afterwards or you will get some residual corrosion.

Aluminium soft solder here: CuP Alloys Limited - Brazing Alloys

also, flux that can be used with soft solder to solder stainless steel, from the same company, here:

CuP Alloys Limited - Brazing Alloys

There is also some good information about soldering generally on this site.

If I can find a supplier of stainless soft solder I'll post it here later-my own stock is getting perilously low.............

Barry

PS - Years ago, a colleague soft soldered Stainless using a flux made from, I believe Hydrochloric Acid, with a neutraliser added.

He called the stuff 'killed spiriits' but I never tried it myself.


Here it is - same company, different page:

CuP Alloys Limited - Brazing Alloys

 

[smokum]

Suppose you could always use a small dab of JB weld to do it.

VapeOn,
Greg

 

[RjG]

Easy way that can't come loose like a screw: cut a small piece of thick copper wire, drill a hole, put something heavy on the other side, and whap it a couple times with a hammer. OR use a vise-grip to squeeze it, etc.
That is now a copper RIVET, and you can solder to that.

 

[invidregis]

I'm going for a "clean" look. So I drilled through the side, then tapped the hole. I then screwed a small steel plug into the case. I covered the outside hole with mighty putty. Now to sand and paint.