Color of old Heavy Formvar wire vs. color of contemporary HFV wire

[Telemachos]

I'm wondering if there is any difference in insulation thickness between contemporary HFV wire and old HFV wire. The color of the old wire looks darker to me. Anyone knows why this is the case?

[Possum]

Its a varnish and gets darker when it ages...

[Telemachos]

Hmmm, that's interesting. Since there is no UV light involved the aging process must be in the varnish composition itself. Thanx for shedding the light.

[David King]

Perhaps it's the copper underneath that is getting darker? It could be that the Formvar is slightly permeable to oxygen allowing the copper to oxidize.

[Telemachos]

Perhaps it's the copper underneath that is getting darker? It could be that the Formvar is slightly permeable to oxygen allowing the copper to oxidize.

Dunno if this process would reach the most inner windings, especially when the PU had been pottet. I've seen the darker wire on countless vintage wire that I had to cut all the way down to the inner winds. Here's a pic that to some extend might show the color difference.

[David Schwab]

Perhaps it's the copper underneath that is getting darker? It could be that the Formvar is slightly permeable to oxygen allowing the copper to oxidize.

I think that's it. On old pickups the insulation is always very dull looking and the whole thing has an oxidized look to it.

[Telemachos]

On the other hand I've noticed SD PUs with HFV wire of the same dark tan that the old PU have.

[big_teee]

On the other hand I've noticed SD PUs with HFV wire of the same dark tan that the old PU have.

Is it possible that the lighter one is Heavy Poly.
It is natural finish, but lighter in color.
This is 42HPN
http://remingtonindustries.com/Conte...0AWG%20HNS.jpg

[Telemachos]

Is it possible that the lighter one is Heavy Poly.

No, it's HFV that I purchased from MWS.

[David King]

Let's just assume that HFV varies in color for manufacturer to manufacturer and batch to batch.

[jonson]

Let's just assume that HFV varies in color for manufacturer to manufacturer and batch to batch.

Spot on David but not just manufacturer to manufacturer, just batch to batch from same source. I put up a pic a year or so ago of a few reels all from one source and the same year but diferent batch numbers and all different shades light to dark. Paint, wallpaper is always a recomended to buy from the same batch no or shades will vary and considering the varnish maker is only interested in the correct formula,, colour does not come into it.