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

[Joe Gwinn]

I would hazard that #42 aluminum wire will be very difficult to handle in practice, and any flux strong enough to work will eat the wire after a year, causing dead-pickup returns.

If the objective is to achieve higher resistance per length, one can achieve the same by using wire 80% the diameter, so if one goes from #42 to #44, one will achieve the same resistance per length as changing from copper to aluminum.

The #44 is smaller in diameter than #42, so the coils will be tighter, which may or may not be an advantage. Some compensation is possible: #44 single build is 0.0028" in diameter, while #44 double build is 0.0025" in diameter, the difference being lost in normal manufacturing variation.

[big_teee]

Back in the 70s, they tried using aluminum wire in mobile homes.
I saw some of it, and it was brittle, easily broken, and had many corrosion issues.
It wasn't used long.
Aluminum is used for service entry, but in larger sizes, like 4/0.
Like DK said, you need to use corrosin inhibitors.
All the old Copper used in Telcomm work like Phone offices, back to the 50s were pure and soft.
Unless you guys come up with a break through, copper is hard to beat.
Or go the other way like Seymour Duncan did on elite pickups, and use Silver wire!
However the cost is the limiting factor with Silver.
There are some Copper Alloys that should be cheaper than pure copper.
GL,
T
** http://www.elektrisola.com/conductor...oys/cuni2.html
Notice that bending gets to be an issue as alloy goes up.
It would be hard to wind something that is too springy!

[Mike Sulzer]

I would hazard that #42 aluminum wire will be very difficult to handle in practice, and any flux strong enough to work will eat the wire after a year, causing dead-pickup returns.

Exactly! The link in the first post shows that somebody makes and sells #42 aluminum magnet wire. Why? Is there some application where weight is really a critical issue?

[salvarsan]

Kanthal lists copper-clad aluminum wire that is solderable.

Perhaps that's a start.

[rjb]

Is there some application where weight is really a critical issue?

(Moving) speaker voice coils.

[rjb]

my suggestion is to do the terminations mechanically, using some variation of the old wire-wrap technique.
...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.

To refresh your memory, the ends of the #30 Kynar-insulated wire were *stripped* and 7-9 turns of *bare*wire wrapped around the post.
Wire wrap - Wikipedia, the free encyclopedia

Does anyone make magnet wire with insulation suitable for IDC connections?

[capehead]

Exactly! The link in the first post shows that somebody makes and sells #42 aluminum magnet wire. Why? Is there some application where weight is really a critical issue?

Yeah, apparently motor armatures use it to reduce their weight, thus increasing their power to weight ratio at the cost of a few extra windings.

Kanthal lists copper-clad aluminum wire that is solderable.

Perhaps that's a start.

If I decide to go with this idea, the copper-clad aluminum will be the way I will do it; although I'm having a hard time finding a supplier who will sell some in smaller quantities.

Back in the 70s, they tried using aluminum wire in mobile homes.
I saw some of it, and it was brittle, easily broken, and had many corrosion issues.
It wasn't used long.
Aluminum is used for service entry, but in larger sizes, like 4/0.
Like DK said, you need to use corrosin inhibitors.
All the old Copper used in Telcomm work like Phone offices, back to the 50s were pure and soft.
Unless you guys come up with a break through, copper is hard to beat.
Or go the other way like Seymour Duncan did on elite pickups, and use Silver wire!
However the cost is the limiting factor with Silver.
There are some Copper Alloys that should be cheaper than pure copper.
GL,
T
** CuNi2
Notice that bending gets to be an issue as alloy goes up.
It would be hard to wind something that is too springy!

Unless the current trend in copper prices evens out, I can easily imagine a future where aluminum electrical conductors become more prominent again with the corrosion issue worked out via copper (or some other less reactive metal) coating. That's what I was saying about the prospect of discount guitar builders using pickups wound with the cheaper aluminum wire for the sake of saving a handful of pennies per unit. I'm not trying to be an electrical industry Nostradamus here, but I can easily see these sort of compromises being made in the future if and when the price of copper approaches that of the precious metals. If that happens I'm getting locking guitar cases to prevent the crack heads from getting any ideas about the scrap metal value of a mile or so of 99.99% pure copper #42AWG, lol!

[David King]

There was one Chinese firm on Alibaba what would do custom copper clad aluminum but the minimum order was 400Lb and I seriously doubt they could go any smaller than 20AWG.

There was plenty of Chinese copper magnet wire for between $8-$10/Kg -that's less than $5/Lb so cost of copper won't be a limiting factor anytime soon.

With aluminum wire I suspect you'll want it pure as you can get it to minimize corrosion and work hardening but that's just a hunch.

[big_teee]

You can buy a big roll of this, and wind a lot of pickups.
Copper is too affordable right now.
Close to 6.5lbs, for a little over a hundred bucks.
Magnet Wire, Enameled Copper Wire, 42 AWG, 0.0026" Diameter, Red : Magnet Wire

[JGundry]

IMHO you are wasting your time. Vintage magnet wire has the same ohm per foot variation as current production Copper wire. I have heard both metal was purer and metal was less pure in the 50's. I have yet o see or hear any real evidence for either argument. I have no problem getting vintage spec. magnet wire ir magnets.

[Joe Gwinn]

IMHO you are wasting your time. Vintage magnet wire has the same ohm per foot variation as current production Copper wire. I have heard both metal was purer and metal was less pure in the 50's. I have yet o see or hear any real evidence for either argument. I have no problem getting vintage spec. magnet wire ir magnets.

Copper is and was refined electrolytically, and technical-grade "pure copper" was just as pure then as it is now.

If people really want to use #42 pure aluminum wire, an ultrasonic welder will prove very useful or essential. This works on bare wire, and requires no flux. They are not cheap.

[Possum]

This is way too simplistic thinking. Yes, magnet wire pre-1965 had impurities in the copper, that comes straight from Elektrisola. Ohms per foot is too simplistic. The insulations modern PE has on it isn't the same as what they made in those days, can I prove that? No. But having wound with a couple full spools of vintage magnet wire now, dating from the 50's, that is the same diameter as stocks of modern wire I have, it is very different sounding, I know some of the reasons from the testing they did for me on vintage wire with alot of parameters detailed in precise lab numbers, but dielectric efficiency of insulation wasn't one of them. But its more than insulation or copper purity, everything done in any materials back then just has no modern equivalent. Unfortunately the wire we are getting now is way way way modern in every detail. And no, the magnet wire makers won't change what they are doing, I've talked to them about it and you would need big funds to push them back into time, it could be done, and I have wire here from 2003-2009 that is much more vintage in every way than anything being made now. But the ones who made that wire are either gone, or doing things in much more modern ways. Its a shame because its an obstacle that you really can't get past.

[J M Fahey]

In Argentina we used to have a small insulated copper wire Factory originally established in the late 40's which still used the old method to coat wire, incredibly crude (but which probably was state of the art way back then, and the same as in USA/Europe): wire gets into a raw varnish pot, then up inside a "chimney" where hot air is blown up>down to predry it, but original coat is very uneven and thick, because varnish itself is thick, so the wet wire passes between 2 felt pads which absorb excess, they did it twice to even out irregularities.

The fun part is that the beginning of the wire gets practically uncoated because dry pads absorb too much, later they become soaked with "incoming" excess and product is "more or less" uniform.

Varnish they used was called "oleo resinoso" , poorly translated as "oily resin based" , a close cousin of standard general purpose "synthetic paint/enamel" .

I know when they used this one because when I burn wire with a lighter (I make transformers and use thicker wire than you) it forms "scales" or a "crust" which must be scraped away, while Epoxy when burnt leaves a thinner and more uniform carbon "dust" coating, visibly very different.

It behaves like wire I find inside oooolllldddd Fender transformers.

In thin gauges wire was sort of oval, meaning you measured it 3 or 4 times at the same point and values did not match.
The wire itself was fine, coating was not uniform.

I guess the old wire you crave must be similar.

In the 90's they scrapped all old rusty machinery, selling it by the kilo, and imported a modern machinery setup, including far more consistent Epoxy coating system.

[Possum]

Concentricity is one of the lab measurements for old wire they did. In other words, how round the wire actually is. They did comment that the 50's wire I sent them was remarkably good in that respect. Percentage of bare wire vs.insulation thickness is another parameter they tested. The worst wire they tested for me was AWC wire which was literally double thick insulation compared to the "increase" of vintage wire, "heavy PE" is what it should have been called.

[Joe Gwinn]

This is way too simplistic thinking. Yes, magnet wire pre-1965 had impurities in the copper, that comes straight from Elektrisola. Ohms per foot is too simplistic. The insulations modern PE has on it isn't the same as what they made in those days, can I prove that? No. But having wound with a couple full spools of vintage magnet wire now, dating from the 50's, that is the same diameter as stocks of modern wire I have, it is very different sounding, I know some of the reasons from the testing they did for me on vintage wire with alot of parameters detailed in precise lab numbers, but dielectric efficiency of insulation wasn't one of them. But its more than insulation or copper purity, everything done in any materials back then just has no modern equivalent. Unfortunately the wire we are getting now is way way way modern in every detail. And no, the magnet wire makers won't change what they are doing, I've talked to them about it and you would need big funds to push them back into time, it could be done, and I have wire here from 2003-2009 that is much more vintage in every way than anything being made now. But the ones who made that wire are either gone, or doing things in much more modern ways. Its a shame because its an obstacle that you really can't get past.

What were the impurities?

What is the mechanism by which they affect tone?