shielding paint vs. copper

[prscrptn]

I'm upgrading the pickups/wiring on my JMJM and question the quality of the shielding.

Is shielding paint in the cavity as good as using copper tubs or tape?

I want to reduce RF and noise as much as possible...

[_nash]

If you have conductivity throughout the cavity and everything is properly grounded including a pickguard shield, then there shouldn't be a difference. Having said that, the guitars I've had with copper shielding have always been quieter then the couple I've had with paint.
I have a JM with only a copper pickguard shield and no cavity shielding and it's very quiet.

[prscrptn]

I purchased an aluminum shield but still wonder if it's worth installing copper when the cavity is already painted.

May be a waste of time, but I figured if I've already got it open, I might as well go the extra mile to make it right.

[Glimmer]

I used copper shielding on mine (cavities + pickguard) but have told myself if I ever build another one I'll use paint. _nash's comment above makes me realize that I'll want to research the paint option further.

[Bradley-Jazz]

I've used paint, and found it to work well. I did take a conservative approach to continuity though - plenty of coats, and a number of connection points to the scratchplate shield and the earth wiring on the pots and to the bridge. Tested it all with a multimeter to check continuity.

I have come across paint shielded guitars on which the paint wasn't very conductive at all....

[sears]

I have definitely had paint-shielded basses which passed a continuity test and because of that, I delayed copper shielding them because I thought it wouldn't help the noise. Copper shielding made a huge difference. I don't understand why. My note comes out of a pit of silence now.

[spacecadet]

I would love to see a real scientific test of this (measurement tools for RF interference must exist) and if I did and it showed something different than what I'm about to say, I would absolutely eat my words... but my personal experience is that copper sure seems to work better.

My CIJ JM came with paint, and it worked fine for its stock pickups. But CIJ stock pickups are quite low in output, and it could also just be that their construction isn't conducive to interference. So it was pretty quiet, and I doubt anyone would have noticed any difference using copper tape.

Once I installed some Antiquity II's, though, which are built more like a regular JM pickup (the coil spread all the way to the edges) and have higher output, I noticed a *lot* of noise. So I shielded it with copper tape, and it quieted it down at least back to the level of my AVRI JM, which is probably all you can expect. I mean they're still single coils, they're going to hum a bit when used individually. But it's definitely less than just with the paint.

Now, it is totally possible that it's the doubling up on the shielding (both paint *and* tape) that helped me, rather than paint vs. tape individually. But just the paint alone didn't seem to work well enough when using proper Jazzmaster pickups.

[fat finger]

http://physics.stackexchange.com/questi ... h-currents" onclick="window.open(this.href);return false;

I'm sure there is an equation for this or something but that web page kind of suggests that a resistive faraday cage only reduces the field strength of the EM waves. That seems to agree with the way that foil shielding works better than paint and paint works a bit better than nothing.

[eternal learner]

My mij jazzmaster has the factory shielding paint, however i stuck down aviation aluminium speed tape over the paint in the cavities as well as the underside of the pick guard , very quiet and to my ears no loss of tone. Has SD vintage for JM pups. Soon to start a makeover on my mascis jm, i have some copper tape and can't decide to try the copper or al tape.

[Singlebladepickup]

I was thinking about doing copper pickguard shield only, like Nash. Does anyone else think more is needed?