Hielding - what's the deal?

Hello all
Well, I've got a telecaster body and a finished stratocaster body. So I'm wanting to start assembling and been thinking about the shielding in the cavities. And then some people say dont waste your time because it doesnt work. Then I've read elsewhere that it does help. All sorts of talk about Faraday Cage and so forth. So what you you guys say? Do you use shielding? I have a bunch of copper tape from Stewmac. Would the shielding paint be a better idea? Are there any alternatives - I'm sure that there must be some or the other conductive paint available in hardware stores?

Cheers - Ed

I shielded my last build and didn't see any difference between it and all the ones I didn't shield. However, I've noticed that almost all brand name guitars are shielded, so I really don't know what to think.

The copper tape is fine, and, unlike paint, you can get it back out fairly easily if you want to.

I prefer guitars shielded and they seem to be better sounding, but it's difficult to prove such a thing.
Hum and buzz from external sources (computers, lights, etc) varies from situation to situation I've found, but if shielding helps in any of them then it's worth having IMO.

I don't think it has any negative effect and, as mentioned, many companies shield their guitars.

One way to kill the buzz in a single coil setup is to disable the middle pickup, but leave it wired in. I did this on accident once, I was relicing a Stratocaster and somehow in the reassembly of the electronics, I damaged the coil wire in the middle pickup. I was putting them back in the body without those plastic covers on and broke one single strand on the coil wrap. It disabled the pickup, but it was still wired into the selector switch and pots, so when you put the selector in Bridge/Middle or Neck/Middle, naturally, there would be no buzz, but only one pickup was actually picking up. Worked fine for me, I never use the middle pickup anyway.

I'm lucky , I don't seem to have a problem with pickup hum at home here..so I never bothered shielding any of them, some have the black paint stock..

I use valve amps.. there's a flouro light over head, the computer is a few feet away, the TV is going, the fridge motor clicks on and off...

and none of these appliances induce any hum in any of my guitars..

with my super 210 on,my Laney cub or my champ copy.. two guitars on the stands with the Volumes wide open ... I can still hear my computer fan and fridge over any hum from the amp/guitars...
even though my fav tele has the most microphonic PU's I have here, and the other one has 2xp90's....

I'm confused as to what makes this hum you guys always talk about?... as computers/flouros/tv's/fridges close by don't bother any of my equipment...

Might be the 240V and the different frequency, Trev.

I noticed a difference when shielding my Baja Tele. Less noise / hum. Worth doing given the minimal effort required in my opinion.

I've shielded a number of guitars. In MOST cases it makes a noticeable difference from before to after. Even with humbucking pickups, there is a difference. Mostly, the difference is with the higher frequency noise such as buzz and crackling. For example, in an unshielded guitar, if you have dry hands during the winter, you can actually hear your fingers moving along the strings by the crackling. Or maybe you hear a buzz UNTIL you touch the strings. Those two situations are clear examples of inadequate shielding.

I've used both copper tape and graphite paint. Both work quite well, but each has advantages and disadvantages. Graphite paint can give the best overall results, and while I don't know, I THINK it's because it has some resistance. I believe that gives static discharges something to dissipate across. The downside is that it takes a minimum of three days to do a shielding job because you need at least three thin coats, and you need to wait a full 24 hours between coats for them to fully dry. You should also finish with a clear coat of some kind to keep graphite particles in place, which adds an additional day or two. If the graphite powders off over time, it can get into switches and pots and cause contact failures.

The copper tape can be done in one sitting, and can be removed if you decide you don't like it. Many members of this forum swear up and down that shielding kills their tone, like throwing a blanket over the speaker. I've NEVER experienced this, and it makes no sense electronically. They claim the shield acts as a big capacitor, but the actual distance of the shielding to the pickups themselves is too far to have this effect.

I strongly advocate shielding, especially on a new build. Or better yet, put it together without shielding and play it for a month. Listen carefully to the amount of buzz that disappears when you touch the grounded strings or another grounded part like the output jack. Listen for crackling that occurs from string handling. Then take it apart again and shield the control and pickup cavities and play it again. If you don't hear a difference in the level of background noise, I'll be amazed. Now, shielding will NOT mitigate 60 hz hum from single-coils, but rather the buzz and crackle I mentioned earlier.

All of my guitars have noise-cancelling pickups and thorough shielding. They are absolutely silent in most environments and venues in which I play. Exceptions include facilities with dimmers or faulty wiring, and in my own house due to some unidentified wiring or AC interference gremlin that renders ALL guitars noisy. This experience alone convinces me that I haven't got this topic completely figured out yet, but what I have learned up to this point I still believe to be valid.

This website gives very detailed instructions on copper shielding techniques. Use this as a basic guide. Go to the link "Quieting the Beast" for Strat, and "The Beast's Cousin" for a Tele.

http://www.guitarnuts.com/wiring/menu.php

Bill Lawrence has a few things to say about shielding. He recommends aluminum tape in certain places (like pickup cavities) to mitigate noise from dimmers. I haven't been able to get that to work yet, but I trust this man. He's forgotten more about guitar electronics than most of us will ever learn.

http://www.billlawrence.com/Pages/Pickupology/External%20Interference.htm

After 30-odd years of carpentry and LOUD muzak my ears ring so much I don't notice if the guitar is sheilded or not! Just turn it up. And up.

I like the paint. It's expensive to buy (but a small can last's forever) and takes longer to do but I think it may have less capacitance and affect tone less.

There has been a very noticeable reduction in noise/hum on every guitar I have ever shielded and there has been no adverse affect on the tone/sound of the guitar.

Shielding it can't hurt but it may help. In my opinion I think a lot of the problems arise from the domestic supply within the place you are playing. In Aus we have a 240V/50cps supply and I think the USA uses 110V @60 cps. The main cause of the 50/60 Hz hum is the supply system earthing. Electrical systems can produce "earth loops" which cause massive hum in some equipment but none in others. Also the type of power supplies within the equipment is many and varied and some work better than others. A few years ago I had to check a problem with a sound proof booth at a hearing centre. One piece of VERY expensive test equipment suddenly started humming like a swarm of bees around an open honey pot. The same equipment in another room ....perfect. The hum could be eliminated by lifting the earth lead from the equipment or the power point but I wouldn't do this for safety reasons. As it turns out the hum was only audible on one power line who's earth stake was approx 25metres away on the other side of a car park. The solution until an electrician could be called was to run the gear on an extension lead from another outlet line. Probably still on the lead. If you have bad hum at home get your earthing systems checked out. Earth stakes have been known to corrode away VERY DANGEROUS!