Wires on 1940 Buick, is this steel?

[Morgan Wright]

I've done a lot of work on rewiring my 1940 Buick. Lights, horns, turn signals. I saw right away the wires weren't copper, because they are silver colored, and assumed they were aluminum, a good conductor that was popular in wiring around 1940. But as I was working on them I kept noticing, these wires are very STRONG, much stronger than I think aluminum would be. They never break. I tighten them at connections, I pull on them, they are strong as heck. It's almost like they are guitar strings or cables. Then I took a really close look....it this steel? Did they actually wire this car with steel wires?

 

No, really. I clipped a sample of the wiring and took a closer look. They used steel cables to wire this car.

[jvelde]

You could use a magnet to see if it sticks to the wires to tell for sure!  

[Morgan Wright]

Ok this blows my mind. It's not magnetic, so obviously not common steel, and it isn't rusty at all, so I thought maybe it's a steel alloy like stainless steel which is not magnetic and doesn't rust. Very strong wire, silver colored, not magnetic. Hmmmm,

 

So I called my 92 year old father who worked in WWII as an electric engineer in the Marines, making airplanes and radar gear. He should know about the wires they used in the 40's. He said, maybe it's tinned copper. What? I said. He said "Tinned copper. They dipped copper in tin so it wouldn't corrode. Try scraping off a strand and see if there's copper under the coating."

 

I took a strand with my jack knife and scraped off the plating and guess what? It's tinned copper!!

[Buicknutty]

 I have seen this before. My '41 had some wires like this, but the insulation was so rotted that nothing could be saved.

 Keith

[Morgan Wright]

On 5/8/2016 at 4:04 PM, Buicknutty said:

 I have seen this before. My '41 had some wires like this, but the insulation was so rotted that nothing could be saved.

 Keith

 

It's a shame to pull wires because the insulation is bad, if the wires themselves are perfect. I notice that much of the insulation on my '40 is rotted, some is so bad I'm in the process of finding the bad ones and coating the bare wires with acrylic. You can just paint the acrylic coating on the wires with an artist's brush, it forms a tough rubbery coating that is a perfect insulator, it's flexible and strong and I'm sure will last for decades. I use Galeria acrylic made by Winsor & Newton, it comes in many colors but I use black. No way am I going to pull out all the wires when I can just coat them. It dries in 5 minutes so I use 2 quick coats. It really works marvellously. I got mine at the local artists supply store.

[Barney Eaton]

It is probably copper with a tin coating to reduce corrosion.   Bare copper will oxidize, a tin or tin/lead (like solder) coating solves the problem

[Buicknutty]

Actually, some of the wires were corroded, and one section was burned up a bit from a high resistance connection. That is an interesting solution to the insulation problem, I did not know it was available. I'm sure that that coating is at least as good as the cotton and rubber that the originals used, likely much better.

Keith

[Morgan Wright]

44 minutes ago, Buicknutty said:

Actually, some of the wires were corroded, and one section was burned up a bit from a high resistance connection. That is an interesting solution to the insulation problem, I did not know it was available. I'm sure that that coating is at least as good as the cotton and rubber that the originals used, likely much better.

Keith

 

On my car the main insulator is air. The bare wires are sticking out all over but bent in such a way that they don't touch anything. Up front where the headlight wires are, most of the insulation fell off and bare wires are all neatly arranged so they don't touch anything. I can't wait to coat all those wires with acrylic. The previous owner wrapped a lot of electricians tape over some bare wires but that stuff is worthless and falling off.

[Grimy]

Where individual wires can be separated, I've used shrink tubing of an appropriately snug diameter.  This usually requires removing the flag or loop terminal at the ends--which usually needed replacement anyway.  It works for a driver!

[Daves1940Buick56S]

Yes, heat shrink works great - I must have a couple pounds of the stuff in my car at this point. You have to unsolder/redo the terms as George said, but the benefit is you get a nice clean solder joint that will work for a long time. For the areas where getting to a wire end is impractical, I use F4 tape rather than electricians tape.

 

Cheers, Dave