Grounding and shielding question. Looooong question.

Hello. I have been stuck sick for a few days and it has been storming like crazy here, so I had to put working on my clear coats on hold. In the mean time, I've been shielding my LP with the paint from Stew Mac. Today when coat 4 dried, I measured it for kicks and I was amazed that it measured very very close to 0 ohms. I have also been reading a lot about wiring and looking at splitting coils... In other words, I've been thinking a lot about new and creative ways to make this project a lot more complicated and expensive. :)

Anyway- In the PB diagram for 2 humbucker, 4 pots, and a 3 way switch, it says "Purple wires may not be required if cavities are shielded and pots are in contact with the shielding." Makes sense to me. I have some very limited (like basic introductory) knowledge about electronics, and so removing the purple wires makes perfect sense. What I am wondering is can the gray wires (ground from pups and bridge and switch) be grounded to the shielding and then the shielding be connected to to the output jack sleeve? It seems that it should be so. I have painted all the cavities and all wire routes, so I have continuity from every point in the shield to every other point. I even painted the route for the bridge ground wire just because I'm a little OCD. And seeing as how the shielding has to be grounded to the sleeve anyway, and that's the only ground leaving the guitar, it seems that that would be OK.

Gav put up a great little diagram here (http://www.buildyourownguitar.com.au...ead.php?t=2900 - sorry i'm not sure how to directly link to another post other than copy/paste the URL) and it looks like everything just goes to ground. But I may be way off and that is just showing shorthand for "connect all these directly to the ground out."

Having said that, I'm a little fuzzy on the difference between an earth and electric ground (more properly neutral?) in this application. Is it that the gray wires in the PB diagram are needed for the circuit to work correctly, it needs a hot and neutral rather than hot and earth? Like If I tried my mad scientist idea I would get zero signal?

Like I said, I only have a little knowledge and having a little knowledge about something is a dangerous thing. And I just kind of like the idea of just running a short little jumper right to the cavity rather than running a wire I might not need (like just grounding the switch right to the cavity rather than running it to a pot).

I'm wondering because I've been eyballing the free-way switch and the HH Coil Split wiring (here http://goo.gl/YZTfFz - this is a pdf link, page 2). On that, there is a ground running from the switch all the way directly to the output. That is what got me thinking about just grounding everything to the shield because on the LP that is a very long connection. Why add one more wire if it isn't needed?

Oh, and one more question, this one a little more straight forward - I have the black hardware on my LP. On the mount for the tailpiece is the black coating conductive or do I need to scuff off some of the coating to get a good contact with the bridge ground?

Thanks and sorry for the length of the post! This is what happends when I have too much time on my hands...

Hi Ken,
think you are over complicating things. The black hardware the bridge post should be conductive but wouldn't hurt to rub off a bit of black so the earth wire makes good contact.
As long as the switch, both pups, all 4 pots and the output jack are earthed to the bridge post it should all be earthed, so if all of these make contact with the shielding and the shielding is grounded you shouldn't need a separate grounding wire to them.
As for coil splitting the pickups you need pups with 4 wires - a north and south ending wire plus hot and earth wire. You can modify the supplied pups to do this unless you have upgraded to coil splittable pickups ?

Looking at some different pickups. Leaning toward the SD Hot rodded set right now... Although I looked at the Lace Alumitone Grillers and thought, "I don't care how they sound those are sexy!"

And you are right. Probably overthinking things. I'd just hate to spend all this time on a cool guitar just to wire up a very expensive paperweight.

Ken sounds good re pup selection.
Just see how you go with the wiring, you won't find out till strings are on and you plug it into an amp. I always find there is a bit of fine tuning needed. Only takes one stray wire to touch another lug or the shielding and it earths the signal

Hi Ken Fu,
the simplest and easiest way in my honest opinion, is shield and earth everthing.
I only use conductive paint in the bridge post holes, I use shielded push back wire, like that sold by Stew MAc, but it is freely available on ebay. I use copper shielding in all cavities. I do not, repeat do not subscribe to the idea of earthing the pots to the shielding. AFAIAC that concept is a bit too hit and miss, as it requires you to make sure the pots contact the shieldong as some may suggest, or you have to solder a tag to the shielding. I think you get a better result from using shielded wire.
As for split coils Love th idea and have done it a few times. You can dismantle two wire coils and do your own split, but beware you may end up with a couple of paper weights. Yep been there done that.
You should have a look at Seymour Duncan tripple shot pick up rings. these make the whole wiring in split pick ups easy.
getting the wiring right for split coils using push pull pots is a whole lot of fun and guaranteed to end with a few burn spots on you fingers. But it is worth the effort.

Cheers PK

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Originally Posted by kells80aus

...guaranteed to end with a few burn spots on you fingers. But it is worth the effort.

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Well, when you make it sound so fun, how can I resist! Ha ha! But those rings are kind of amazing. I had not heard of those. I think I might just have to try those out instead of the free-way switch... Thanks PK!

EDIT: In the interest of future reference, PK was totally right. I tried just using the "solid contact with the shielding" when wiring up my guitar, and it worked well except the neck tone pot made maybe a 1% difference. You could kind of hear it, but only if you listened hard. I went ahead and physically wired the ground connections, and it made a marked difference with everything. Both tone pots have a wider range and are much smoother.