PE and me...

[fjgaston]

We don't hear past 20KHz.
but we can hear the difference between two impulsions separated by more than 0.00001s and one impulsion alone.
That's we use a sampling frequency up to 192KHz (almost 2x100,000 because 100,000 is 1/0.00001) for a High Quality of sound, that's the point.

I just built a Humbucker with Heavy Formvar, I'm a beginner in pickup building but it sounds better than the 1985 Tim Shaw PAF I have on my Les Paul. There are more harmonics, more dynamic. I like it

[Spence]

Spence, I said fill me in, not fill me UP! And all this from a man with a sheep. That always sounds plural, sheep. Is a singular one a ship?

No, a single sheep is a special little lady.

[Possum]

an easy test...

If you think insulation has no effect and that they are all the same, well you're wrong. So you say the insulation perfectly keeps the wires from affecting eachother and the only effect is how thick? Here's a real easy test to blow that idea away. Get an LCR meter, the Extech is the best, take your measurements. Now dunk the pickup in WATER. Now take your readings. You will notice that the pickup has gone to hell, all the readings show it suddenly got muffled and dark sounding and if you put it in a guitar and play it you'll hear what a drowned pickup sounds like. Now if the insulation were a perfect insulator the water would have no effect. I'm guessing what happens is water is a pretty good conductor and what you're seeing is the current being affected by the water THROUGH the insulation. This is why I don't use shellac anymore, shellac has water in it and if it fails to dry properly, which with 43 guage or finer it probably will never dry, the water in it turns your pickup into mud. If water can have this effect then the dielectric specs on each of the different insulators, if they are different will have a different effect on how well it is insulating the current , even at very low voltages. Science.....

[Joe Gwinn]

If you think insulation has no effect and that they are all the same, well you're wrong. So you say the insulation perfectly keeps the wires from affecting eachother and the only effect is how thick? Here's a real easy test to blow that idea away. Get an LCR meter, the Extech is the best, take your measurements. Now dunk the pickup in WATER. Now take your readings. You will notice that the pickup has gone to hell, all the readings show it suddenly got muffled and dark sounding and if you put it in a guitar and play it you'll hear what a drowned pickup sounds like. Now if the insulation were a perfect insulator the water would have no effect. I'm guessing what happens is water is a pretty good conductor and what you're seeing is the current being affected by the water THROUGH the insulation.

You will get this effect even if very pure (and thus non-conductive) water is used, because the dielectric constant of water is about 80, compared to about 3.5 for wax and magnet wire insulation, and 1.0 for air. One effect of pure water would be to sharply reduce the self-resonant frequency.

Prevention of waterlogging from condensation is why Leo invented wax potting of pickups. Salty water would be worse, and one would never get all the salt out.

As for shellac, one can force it to dry by use of heat and vacuum. Too much trouble for production, but could be used to verify the theory that it's the fact that the shellac has not dried is the cause of the muddy tone.

I gather you have tried the waterlogged pickup experiment. What were the numerical results?

[Possum]

....

No I didn't try the waterlog experiment. I used shellac and it works with 42 gauge PE but with 43 when I tried it, a day later the Extech readings were awful, I thought the wire had shorted out so cut it open to take the coil off and found it was wet and sticky inside. I had another like it at the same time so roasted it in a toaster oven. Even after hours it refused to dry out, the thin wire was wicking it to keep it inside deep in the coil where it can't dry out. I think someone told me shellac has water in it on the forum so I just quit using it altogether, end of story. But it does point out that you should pay attention to what the insulator on wire is.

[Joe Gwinn]

No I didn't try the waterlog experiment. I used shellac and it works with 42 gauge PE but with 43 when I tried it, a day later the Extech readings were awful, I thought the wire had shorted out so cut it open to take the coil off and found it was wet and sticky inside.

I think I recall this discussion.

I had another like it at the same time so roasted it in a toaster oven. Even after hours it refused to dry out, the thin wire was wicking it to keep it inside deep in the coil where it can't dry out.

At what temperature? It can take days, not hours, unless vacuum is also used, or the temperature is high. One needs to stay near or above the boiling point of both alcohol and water for an extended period. Vacuum reduces the boiling points of both, making removal easier. But pickups can withstand 200 degrees F pretty much forever, unless the bobbin plastic is not good.

I think someone told me shellac has water in it on the forum so I just quit using it altogether, end of story. But it does point out that you should pay attention to what the insulator on wire is.

It may have been me. Brand new shellac will have little water in it, but alcohol avidly absorbs moisture from the air, and so quite soon there is water in the shellac, and it does not take much water in a pickup to properly spoil things.

[SK66]

If you think insulation has no effect and that they are all the same, well you're wrong. So you say the insulation perfectly keeps the wires from affecting eachother and the only effect is how thick?

As I believe was noted elsewhere in this thread...The insulation of all types is more than adequate for the purpose. I will say that PE/Formvar tends to crack as it ages or with improper winding and the resulting flaws in the insulation could have a significant effect, especially if the pickup is potted.

All of the "characteristics" of PE/Formvar can be duplicated with Poly thru winding technique. PE/Formvar would not be able to duplicate Poly when wound perfectly evenly (I believe).

IMO, these differences may be measurable, but not "hearable" in a practical sense. This is like arguing over Poly vs Paper-Oil tone caps....

[David King]

Any lacquer, varnish or shellac you dip a pickup in will take forever to dry but not because there's water in there. The problem is that as soon as the surface dries and shrinks down it seals in all the remaining volatiles and traps them. This is why epoxy is better, it's anaerobic. Motors and transformers are dipped in a non-volatile varnish and baked until the varnish hardens from the inside out. Shellac is actually an excellent vapor barrier, you just need a very thin coating of it.

[Possum]

...

Yes and the other reason is that 43 gauge wire acts more as a sponge than 42 does and is more tightly packed with more tiny spaces to suck the liquid into the core, so thats why I couldn't get it to dry out by oven cooking it. Cooking something in an oven for days is ridiculous if you want to make a living doing this. It is useable for 42 PE but just don't use it at all anymore.

One thing I just learned about formvar you can read in its descriptions is they recommend annealing the wire if its being wrapped tightly around a small radius or something, so its a good idea to pot that wire for that reason. Its the insulation that gets annealed, not the copper.

[David Schwab]

Any lacquer, varnish or shellac you dip a pickup in will take forever to dry but not because there's water in there. The problem is that as soon as the surface dries and shrinks down it seals in all the remaining volatiles and traps them. This is why epoxy is better, it's anaerobic. Motors and transformers are dipped in a non-volatile varnish and baked until the varnish hardens from the inside out. Shellac is actually an excellent vapor barrier, you just need a very thin coating of it.

I cracked open an old broken Lawrence pickup that was potted with clear polyester resin that I had since the 80's, and it was still not fully cured on the inside! You could smell it as soon as I had the case open. I hate the smell of that stuff!

I've been having good luck dipping my bobbins in polyurethane and letting them sit overnight to a couple of days. You can't even smell it at that point.

Of course after I epoxy them it's a moot point anyway.

[Joe Gwinn]

I cracked open an old broken Lawrence pickup that was potted with clear polyester resin that I had since the 80's, and it was still not fully cured on the inside! You could smell it as soon as I had the case open. I hate the smell of that stuff!

Sounds like a bad mix to me. Epoxy will do the same, but has no giveaway smell.

[David King]

Polyester is like epoxy, it cures fully without air, the smell has nothing to do with the cure, cut into any old surfboard or polyester finished guitar and you'll get that styrene smell. The styrene is there to allow the uncured resin to flow but once the polymer chains are linked up in the cure the styrene has nowhere to go and can't get out.

[David Schwab]

I figured it was a bad mix, and I remember there were a few tacky spots inside. The smell went away after a while.