Easy Soldering to Aluminum?

Question

I am building an antenna with aluminum elements.

Is there any easy way to solder copper wire to the aluminum? I do not need a very strong connection, just a good electrical connection so I can then apply glue etc.

I tried sanding the aluminum and applying cooking oil, but that didn't seem to work. I will try motor oil later, but I don't think that will be any different.

The aluminum is a 1/4 inch rod.

I got it to work on aluminum foil, but it won't work on the rod for some reason?

Would something like this work?

Soldering to aluminum is very difficult under the best circumstances. The rod is probably too large a mass to solder to; consider welding a chunk of copper to it and soldering to that. — Ignacio Vazquez-Abrams, Mar 22 '14 at 23:34
maybe I will just find another way to attach the copper without soldering — skyler, Mar 22 '14 at 23:51

score 5 · Answer 1 · answered Mar 23 '14 at 02:48

5

One well-known solution is to use a piece of polyvinylchloride tube as flux when soldering. It's better to solder with a slightly overheated soldering iron this way. Then resolder the same connection with some neutral flux.

I don't know the exact chemistry of this method, but it worked for me to solder aluminium wires (but not thin foil). It's better to do it in a well-ventilated place.

answered Mar 23 '14 at 02:48

motoprogger

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I would guess that the chemistry is Al2O3 + (carbon, chlorine) = CO + 2AlCl3 The aluminium chloride sublimes at 182C. Having discovered that it is basically impossible to solder to aluminium with regular solder/flux, I am very curious about this, and despite the toxic fumes, will probably try it out. – Level River St Mar 23 '15 at 23:22

score 4 · Answer 2 · answered Mar 23 '14 at 01:38

4

One thing I've seen several times on both DIY and smaller commercial antennas is using a combination of screws and washers or solder lugs to attach the feed to the antenna elements. Here's one idea from Homemade 14 element Yagi antenna for PMR446 that would be pretty easy to put together:

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answered Mar 23 '14 at 01:38

PeterJ

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Mechanical connections are the best solution short of welding. A thin copper tube just barely wider than the aluminum antenna tube, pushed on then crimped would also work. – Passerby Mar 23 '14 at 02:51

score 2 · Answer 3 · answered Mar 23 '14 at 01:46

2

Between the time you sand it and apply the oil, it oxidizes again. If you're going to have a chance, you would have to apply the oil and then sand with the oil in place. This still does not make it easy.

answered Mar 23 '14 at 01:46

gbarry

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Easy Soldering to Aluminum?

3 Answers3