Pickup Cavity Shielding

[De Trepagny]

Is it necessary to shield pick-up cavity? I saw some cavity with dielectrical paint, is that a necessity if the pickup are urethane potted?

thank!

Philippe

[thegarehanman]

Pickups are potted to reduce microphonic feedback, not to provide any shielding from electronic interference. Whether you shield your cavity or not should depend on the type of pickup you're putting in. If you've got a humbucker with a metal cover, than it's already shielded(assuming you've grounded the pickup wire's shielding), but if you've got something like a single coil or p90 with a plastic cover, you may want to shield the cavity. You can use either graphite impregnated paint or copper(or even aluminum) tape. Now, keep in mind that some pickups will have a layer of shielding tape underneath the black tape they're wrapped in. This will serve the same purpose as a metal cover in terms of shielding, more or less. Shielding the cavity of a pickup like this really wouldn't accomplish much.

You take it from there...

peace,

russ

[Son of Magni]

Dielectric paint would be non-conductive paint. Useless for shielding. Stewmac sells the graphite mixed paint that I use. But I only use it for the controls compartment. As Russ mentioned, most pickups are pretty well shielded on the back.

[spazzyone]

i copper sheild all my compartments,pickup routes with copper foil

and all of these areas are connected to each other by soldering a wire

to each route. and with this setup i am able to remove the string ground at the bridge

with no noise here is a pic

http://i32.photobucket.com/albums/d38/femf...tar/rich002.jpg

this also prevents a possible electric shock in case my marshall shoud have any problems

as it is a tube amp, i will still get one if i touch the pots though

[De Trepagny]

i copper sheild all my compartments,pickup routes with copper foil

and all of these areas are connected to each other by soldering a wire

to each route. and with this setup i am able to remove the string ground at the bridge

with no noise here is a pic

http://i32.photobucket.com/albums/d38/femf...tar/rich002.jpg

this also prevents a possible electric shock in case my marshall shoud have any problems

as it is a tube amp, i will still get one if i touch the pots though

Nice shielding spazzyone! There's a ground wire welded to the bottom plate (copper) of the pick-up, so i assume they're shielded (Delano). Thank a lot for you're helpful information! Realy precious

Does graphite lubrifiant can work? They dont dry complettely but i saw some cavity that let graphite mark on my finger.

thanks!

Philippe

Edited October 30, 2006 by De Trepagny

[spazzyone]

im sure it works as a lot of companies/people use it

but nothing beats a full copper sheild

[Son of Magni]

...Does graphite lubrifiant can work? They dont dry complettely but i saw some cavity that let graphite mark on my finger.

thanks!

Philippe

The graphite paint will come off on your fingers.

Are you talking about "Liquid Wrench" of something like that? I wouldn't get that anywhere near an instrument

Edited October 31, 2006 by Son of Magni

[De Trepagny]

...Does graphite lubrifiant can work? They dont dry complettely but i saw some cavity that let graphite mark on my finger.

thanks!

Philippe

The graphite paint will come off on your fingers.

Are you talking about "Liquid Wrench" of something like that? I wouldn't get that anywhere near an instrument

I had a graphite spray can that dry completely and i tried it tonight. That dont let mark on finger, but the graphite film is very light. I'll order 1/2 pint of graphite shield from Stew next time.

Philippe

[thegarehanman]

If you're ordering from stewmac, you might as well get the copper tape instead of the graphite. It's much more conductive than the graphite paint. Infact, I shield my control cavities and make sure there's really good adhesion, then I seal all of the edges with a little bit of CA. Once it's all said and done, the pots don't need to be grounded because they come in contact with the copper tape and you can even solder grounds from pickup leads etc. to whereever's convenient on the copper foil. Although I should stress that you need to make sure the copper adheres well to the wood and that you check everything(and I mean everything) with a multimeter to make sure you have coninuity between all grounds.

peace,

russ

[blackburncustomguitars]

Is it necessary to shield pick-up cavity? I saw some cavity with dielectrical paint, is that a necessity if the pickup are urethane potted?

thank!

Philippe

Hi,

A nice option that I often use is Cu-Pro-Cote, which is a water-based copper paint. I have found it really works well, is easy to apply, but a little expensive.

Peace,

Dave

[spazzyone]

i get my copper on ebay

12"x12" sheets for like 5 bucks and cut each peice with an overlap

and i also ca the edges and fully solder all the joints not just spot soldering!

this is the best sheild you can get bar none

here is a pic of the same guitar but the control cavity

http://i32.photobucket.com/albums/d38/femf...tar/rich001.jpg

note the heat shrink. those lose wires are a pickup i was messing with

its now complete

[De Trepagny]

i get my copper on ebay

12"x12" sheets for like 5 bucks and cut each peice with an overlap

and i also ca the edges and fully solder all the joints not just spot soldering!

this is the best sheild you can get bar none

here is a pic of the same guitar but the control cavity

http://i32.photobucket.com/albums/d38/femf...tar/rich001.jpg

note the heat shrink. those lose wires are a pickup i was messing with

its now complete

Now... why copper? Aluminum tape offer good conductivity and you can find it at your hardware store. Copper look good, i will put in on my "à acheter" list on my next stewmac order.

I test graphite lube on a small piece of wood with my multimetre and there's no conductivity. Useless

thanks for your help!

Philippe

[thegarehanman]

You really shouldn't have to run solder over the whole overlap. Most copper tape is meant to conduct on both sides, making just an overlap all that's necessary. Looks like somebodylikes their heat shrink tubing; I use it but just on leads, not grounds.

That's the first guitar I built, an lp. I just rewired it. It originally had the stock lp wiring. I switched out the pickup toggle for a kill switch, the neck vol for a master vol, the neck tone for a neck/bridge pan pot, the bridge vol for a master treble cut, and the bridge tone for a master bass cut. Notice two things: I didn't solder the copper tape lap joints, and instead of grounding to one physical central point, all grounds went to the shielding(which effectively does the same thing). It's much like how ground connection work on a metal chasis. Needless to say, there's continuity throughout all ground connection and the thing sounds great.

peace,

russ

PS Aluminum tape should work just fine. Aluminum isn't quite as conductive as copper, but in this case it doesn't matter. It will certainly work better than the conductive paint.

Edited November 4, 2006 by thegarehanman

[De Trepagny]

and instead of grounding to one physical central point, all grounds went to the shielding(which effectively does the same thing). It's much like how ground connection work on a metal chasis. Needless to say, there's continuity throughout all ground connection and the thing sounds great.

That's exactly what i've done yesterday! I test the conductivity by putting a pole on the aluminium shield and the other pole of my multimeter to the body of my pot and there 100% conductive, so dont need to ground every pot = cleaner job.

thegarehanman: how do you ground your cavity cover? I dont see any copper shield extension that goes where the cover sit. I'm just curious

Philippe

Edited November 4, 2006 by De Trepagny

[thegarehanman]

That picture was taken before I fiddled with the control cavity cover or output jack. All I do is take a small piece of copper tape and fold it over the lip of the cavity so it sits under the control plate and overlaps the rest of the shielding. I normally locate it near a screw(or magnet if it's a magnetized cover) so that I'm assured the cover will be pressed against the lip in that area. I then put some copper tape on the control plate. There's no need to put shielding tape on the entire ledge that the cover sits on.

Oh, and if anyone wonders why I do it this way, it's because I think it looks cleaner and because I absolutely hate soldering to the back of pots. I think it looks sloppy[read: I think it looks sloppy when I do it].

peace,

russ

Edited November 4, 2006 by thegarehanman

[spazzyone]

yes im exsesive with soldering and heat shrink but i leave nothing to chance

plus it looks like i know what im doing

[Rick500]

I'm assuming the aluminum tape that's been mentioned as acceptable, is the type sold for the purpose of sealing ducts? (Not talking about "duct tape,"

but the aluminum variety that is actually used on ducts.)

[modman]

I really wouldn't bother trying to find the right tape. I used aluminium foil from the supermarket, thickest they have.

I use an entire sheet and squeeze that in. Really helps the conductivity of the shield to keep it in one piece. Really no way of knowing whether your pickups need it, but certainly wouldn't hurt. Would do stargrounding too (and before anything else)

When I shielded, stargrounded my old japstrat and put a treble bleed on the volume, it felt better than a buying a new guitar.

more pics and info on this way of shielding

good luck,

j

[USAF1989]

Rick500, yes, the aluminum tape used to seal ductwork will work. I use that, and have never had any problems. It's inexpensive, adhesive-backed, and another roll is 5 minutes down the road.

I'm impressed with the wiring & shielding you guys have shown. Very clean and professional looking. Don't you hate when you open one up that looks like a spider's been living in it! Ha!