Using Aluminum Magnet Wire to Simulate the Lower Quality Copper of Yesteryear?

[capehead]

Hi guys; progress on building my new winder is on hold due to my outside work-space being rained upon so until the weather clears up, I guess the best I can do is some 'academic research'. Anyways, the other night I was looking at a topic on this forum (I can't find it now though) that was comparing the differences between old and new wire of which one of the key differences that stuck out with me was the old wire was slightly less conductive due to a less pure copper quality. Within the conversation, it was also pretty much concluded that within the standardization of the copper wire industry today it would be almost impossible to find a wire company which would be able to reduce the quality of their copper to satisfy a small niche market, especially when almost everyone else who uses copper magnet wire desires the purest quality possible for the price. This quandary got me thinking though; isn't aluminum wire by nature is less conductive than copper? I suppose the crux of the matter would be by how much is it less conductive, especially if the numbers are way off in comparison between old wire, new wire and aluminum wire. Would anyone here happen to have any first hand experience using aluminum wire; or even better compared the specs and end results (sound wise) vs copper wire? If the numbers add up with this, the very good thing I've found is that it seems that aluminum wire is a bit cheaper per pound/kilo, see here of what I've found: High Quality 42 Awg Magnet Aluminum Wire - Buy 42 Awg Magnet Aluminum Wire,42 Awg Magnet Aluminum Wire,42 Awg Magnet Aluminum Wire Product on Alibaba.com

[rjb]

I suppose the crux of the matter would be how to connect the aluminum magnet wire to copper hookup wire.
Can't solder them directly.

[capehead]

I suppose the crux of the matter would be how to connect the aluminum magnet wire to copper hookup wire.
Can't solder them directly.

I thought of that too and while it isn't as easy as soldering copper wire, it isn't completely impossible; from what I've read about it thus far it seems that one would need more heat and a different solder composition. Although everything I've read about has related to soldering standard type wire, in regards to #42/43+ wire, there may be a different procedure needed. One of which I had an idea about using a very small copper tube which would be placed around the pickup leads and the magnet wire, crimp/compress it together and then fill it with traditional solder. Whatever way you do it would be more of a process but if the end results sound good, I have no doubts it could be made to work.

[capehead]

Here's something I found on the Elektrisola website regarding soldering aluminum magnet wire:"Soldering of aluminum is possible, but there are a number of critical areas that need tight control. Tenacious aluminum oxide makes most attempts to solder using conventional methods difficult. Flux must be used because of the rapid formation of an aluminum oxide layer, which is difficult to remove and prevents the solder from wetting the aluminum. The reason aluminum oxide is more difficult to remove compared to copper is because of its very high melting point of 2030°C, compared to the 660°C of pure aluminum. Another reason the aluminum oxide is difficult to remove is its high corrosion resistance value. Therefore, more aggressive fluxes are often required, such as an organic amine-based flux (up to 285°C), or inorganic fluxes (e.g. sodium hydroxide up to 400°C). An ultrasonic soldering bath may also be used to crack the oxide layer and wet the aluminum without the use of flux."

[David King]

When aluminum wiring was commonplace in houses most of it was copper plated. The solid aluminum conductors commonly used for the mains feeder from the power line uses mechanical connectors and a special gel is applied to stop oxidation and maintain conductivity over time.

[J M Fahey]

Agree and add, back to the original point: any difference between resistance of, say, 99% pure copper of yesteryear vs. modern 99.9% copper is absolutely irrelevant (less than 1%) compared to, say, the diameter tolerance when drawn, the wire tension or the exact number of turns.

While copper to aluminum difference is in the order of 80% , definitely not what you want .

[capehead]

Agree and add, back to the original point: any difference between resistance of, say, 99% pure copper of yesteryear vs. modern 99.9% copper is absolutely irrelevant (less than 1%) compared to, say, the diameter tolerance when drawn, the wire tension or the exact number of turns.

While copper to aluminum difference is in the order of 80% , definitely not what you want .

You know I've been spending all day trying to find the proper specs of aluminum magnet wire; particularly it's ohms per foot/meter/ect ratings and I have yet come across anything relevant to the issue. Honestly this idea was more of a guess based on a readily available alternative as opposed to the prospect of obtaining custom made wire. Although with the lower prices I've seen for aluminum wire (in comparison to copper), it might almost be worth it to buy a small roll and see how it sounds.

[David King]

A lighter weight pickup would also be nice but there are other ways of getting to that. Whatever you do find out I know we would all appreciate it if you would report back.

[capehead]

A lighter weight pickup would also be nice but there are other ways of getting to that. Whatever you do find out I know we would all appreciate it if you would report back.

Weight reduction would be the least I would hope to achieve, but hey it is a plus I suppose, lol! As much as I would like to just go right ahead and order a roll, my financial situation at the moment dictates otherwise. It is definitely something that is on my agenda to try in the near future though. One thing I'd like to know is whether aluminum would be more or less fragile/prone to breaking than copper? I'm sure it's different in some way or another for better or worse; I guess it's all a matter of trying it out for myself. First things first though is I gotta get my machine working and then get back into the groove of winding pickups (with the regular copper wire I still have) again as I haven't wound any in just about 10 years. I would like to say that this portion of the forum has been immensely helpful in my re-education (plus tons of more info I never knew before). I initially was planning to build this winder with the sole intention of winding transformers and coil chokes, but spending time on this forum has given me the inspiration to try my hand at pickups again; so now my winder is designed to do both ; )

[Jason Rodgers]

How about this info?
Aluminium wire ? Kanthal

[salvarsan]

You know I've been spending all day trying to find the proper specs of aluminum magnet wire; particularly it's ohms per foot/meter/ect ratings and I have yet come across anything relevant to the issue.

Here's a quick and dirty resistance calculator link for arbitrary lengths of wire, tubes, and strips. Use a non-copper conductor from the bottom select box.

Resistivity Calc

FWIW, #42 copper is 1659 ohms/1000 ft and aluminum is 2522.

[capehead]

How about this info?
Aluminium wire ? Kanthal

Oh wow, the difference is pretty big; it says that (with whatever wire their using to base these results on) copper wire is 1.72 ohms per centimeter (I think that's what it is saying) and aluminum is 2.79 ohms. I'd call that a fairly large difference, especially when multiplied thousands of times over. So I suppose my original theory is busted but I'm not disqualifying it's usage completely as I'm sure in the right configuration it might sound good.

[capehead]

Here's a quick and dirty resistance calculator link for arbitrary lengths of wire, tubes, and strips. Use a non-copper conductor from the bottom select box.

Resistivity Calc

FWIW, #42 copper is 1659 ohms/1000 ft and aluminum is 2522.

Yeah, that is like a 1.5x greater difference in resistance; again I concede defeat in respects towards aluminum perhaps being similar in resistance with a lesser pure copper quality. As towards a potential practical usage for it; I figured perhaps the effect of the higher resistance might be similar to using a smaller than #42 gauge? As in the treble response would be more subdued?

[Bruce Johnson]

If you do decide to try winding with aluminum wire, my suggestion is to do the terminations mechanically, using some variation of the old wire-wrap technique. Remember that? Little sharp-edged square pins that stood up vertically. You wrap the wire tightly a bunch of turns around the pin, and the corners cut into the wire in a whole bunch of little notches. Wrap it, test it, and coat it with epoxy to seal it up. I've never tried it with aluminum wire, particularly down in these little sizes, but it seems to me that this would be a simpler and more reliable way of terminating than using solder and flux.

Using aluminum wire is an interesting thought. There may be some odd pickup configurations and formulas that could use it.

[capehead]

If you do decide to try winding with aluminum wire, my suggestion is to do the terminations mechanically, using some variation of the old wire-wrap technique. Remember that? Little sharp-edged square pins that stood up vertically. You wrap the wire tightly a bunch of turns around the pin, and the corners cut into the wire in a whole bunch of little notches. Wrap it, test it, and coat it with epoxy to seal it up. I've never tried it with aluminum wire, particularly down in these little sizes, but it seems to me that this would be a simpler and more reliable way of terminating than using solder and flux.

Using aluminum wire is an interesting thought. There may be some odd pickup configurations and formulas that could use it.

That's a good idea Bruce; much easier than the special fluxes and other stuff which would likely damage the wire. Although in the link Jason Rodgers posted, that company has copper coated aluminum which might be a more logical way to go depending on price and availability. Either or though, I can imagine some interesting combinations with aluminum wire so long as my current assumptions about it hold true. In my search of a reference to a pickup wound with aluminum wire and it's perceived sonic effect has yielded little; only this one short section on a strat pickup Curtis Novak wound with vintage, blue coated aluminum wire: Curtis Novak Pickups www.CurtisNovak.com: Custom Pickup: Teisco Lap Guitar 7 String 50's It is interesting to note that his impression was that there appeared to be nothing out of the ordinary about it. Who knows though, if the sound of aluminum wire is pretty much the same and copper prices keep rising then it is inevitable we might be seeing pickups wound with it in the future; more likely from the far east companies before anyone else. On second thought though, once the patent on those Lace Sensor Alumitones expires I figure that will be the shape and form numerous discount pickups will take since by all indication they are simple and cheap to manufacture.