Capacitance raising potting solutions/dielectric effect....

[Bruce Johnson]

Maybe try wrapping shielding around the outside, but only go partway up? Find some amount of shielding that softens the tone the amount that you want, but not as much as a complete outer wrap?

Or, start hand wrapping turns of a heavier wire around the outside, keeping the start connected to ground. That way, you could adjust the shielding effect on the same pickup while listening to it.

[David King]

Bruce,
That's starting to sound pretty clever and is BOUND to throw off commercial spies when they see your pickup wrapped in 16AWG...

David, Shellac use as a finish goes back about 5000 years. Nitro started up in the 1880s or 1910s. The darker shellac is less refined. The lighter color ambers to clear are actually a bit harder. I couldn't tell you what the density differences are if any between the raw and the refined but most shellac used in luthiery is "de-waxed". A lot of folks just use good old Bullseye brand which isn't particularly transparent but it's cheap, tough and has a good long shelf life compared to home cut shellac flakes. The only virtue to cutting your own flakes is that you can use grain alcohol or everclear instead of denatured alcohol which kills your brain in no time.

[Possum]

......

Well I tried what I thought would be a winner, india ink. Its conductive, the pigment is super fine etc. Beaded up on the coil and didn't want to penetrate and pretty much didn't. No effect at all, didn't go below one or two layers....

[Joe Gwinn]

Well I tried what I thought would be a winner, india ink. Its conductive, the pigment is super fine etc. Beaded up on the coil and didn't want to penetrate and pretty much didn't. No effect at all, didn't go below one or two layers....

Ink is formulated to not soak through the paper, the exact opposite of what one wants to do to that hapless coil. One thins india ink with a dilute solution of ammonia.

[Possum]

...

Would ammonia be dangerous in a coil, its a base right? Meaning the opposite of acid, so any tiny chip in the insulation wouldn't it get in and corrode the wire?
Wonder if lamp black could be bought raw and mixed in shellac, if it would penetrate....

[Possum]

....

I wonder if carbon would even work at all, I sprinkled the coil heavily with graphite all around it and got no indication of any change from the LCR meter...

I have this conductive gel adhesive for electrodes, its messy and too thick to penetrate coils, I read there is some kind of electrolyte in that stuff that works, I wonder if that kind of approach might work?

[Joe Gwinn]

Would ammonia be dangerous in a coil, its a base right? Meaning the opposite of acid, so any tiny chip in the insulation wouldn't it get in and corrode the wire?

It's like one drop of ammonia, which will all evaporate.

Wonder if lamp black could be bought raw and mixed in shellac, if it would penetrate....

It takes a ball mill to really disperse the lamp black in shellac, a stunningly messy process. But it will work - you will have reinvented ink.

How to Make Indian Ink | eHow.com

[Possum]

...

Hmmmm, worth another attempt then, the article has some ideas, I wonder if burned charcoal is conductive....

[David King]

Possum why not try that grease they use on electric panels for sealing the air away from aluminum conductors. I think it's slightly conductive. There's always conductive epoxy too...

[Possum]

...

Well, having tried castor oil, anything slipper makes taping the coil nearly impossible. It'd be better to use something that is not actually solidifying the coils, I did see those expoxies, doesn't appeal to me at all...
I supposed grease could be teflon taped, maybe...problem is grease won't penetrate, castor oil probably would have worked but it wouldn't penetrate the coil at all....

[Joe Gwinn]

I wonder if burned charcoal is conductive....

No, it's carbon dioxide gas. The ashes probably aren't conductive.

But charcoal is conductive.

[Joe Gwinn]

Possum why not try that grease they use on electric panels for sealing the air away from aluminum conductors. I think it's slightly conductive.

The stuff used for aluminum conductors is zinc dust in silicon grease: IDEAL INDUSTRIES, INC. - Noalox Anti-Oxidant Compound.5 oz. Tube. Be aware that this stuff does not conduct electricity unless crushed between two pieces of metal bolted together.

[EFK]

How about raw linseed oil? Don't know what type of dialectic effect it might offer but (1) it can be heated to typical wax temperatures so it will thin and penetrate, (2) it will dry *sort of* but will stay 'gummy' over time and (3) you can easily clean it up with turp or mineral spirits so as to tape the outside of the coils. It will stink though. Boiled linseed oil could also be used but it will dry to a greater extent (not so much the commercial stuff - still flexible when dry).

[Joe Gwinn]

How about raw linseed oil? Don't know what type of [dielectric constant] it might offer but (1) it can be heated to typical wax temperatures so it will thin and penetrate, (2) it will dry *sort of* but will stay 'gummy' over time and (3) you can easily clean it up with turp or mineral spirits so as to tape the outside of the coils. It will stink though. Boiled linseed oil could also be used but it will dry to a greater extent (not so much the commercial stuff - still flexible when dry).

The oil has a dielectric constant of 3.2 to 3.5, which rises to ~5 when oxidized (boiled, maybe as a dried film). So, it isn't all that different from wax.

[Possum]

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Castor oil is the exception, very high rating, the problem with that stuff though, is that when it gets warm it goes higher, so in summer your pickups would be too dark....