A few questions about shielding

[runtfan]

Greetings all.

I am getting ready to build my first guitar, and I have a few questions about shielding.

1. Someone suggested using aluminum tape from Home Depot.  Has anyone tried this?  Does it work better than the copper stuff you can buy from W?
2. The same person mentioned that the wires connecting the grounds on the pots are unnecessary.  Has anyone tried this as well?  Assuming that I do a good job with the conductive paint/metallic tape, it sounds like it should work.  I would of course test for conductivity with an ohm meter.
3. Does the pickup selector switch cavity need to be shielded?

Thanks in advance!

 

[SkuttleFunk]

1. it depends on what you mean by 'better' ... cheaper = yes, but it's awfully tough to solder aluminum

2. wires connecting the pots to ground can be necessary depending on exactly which pots you use. one example of it not being enough would be a case where you use a stacked pot - only the pot half that connects to the threaded shaft will be grounded, the other half will be isolated and thus inoperative. look and you'll find more

3. it depends on what you mean by 'need to be'


my question to you is this: do you clearly understand what each of these actually does? I'd suggest learning about the role of each component that makes up your electronics (shielding included), how changes in each component impact the overall circuit, and how each of these changes ultimately does/doesn't impact your tone in an audible way.

there's more than one way to assemble a guitar and wire it up - you'll only know for sure what each substitution does if you try it yourself one small change at a time. and then, once you know from personal "having done it" experiences, you won't be relying on opinions of someone who may have only read about it or performed that aspect on one or two guitars before becoming an 'internet authority' on the subject

all the best,

R

 

[Rick]

1. Someone suggested using aluminum tape from Home Depot.  Has anyone tried this?  No.
Does it work better than the copper stuff you can buy from W?  I've used plain aluminium foil and it works, though if it sounds better than copper I can't say.  I can't tell a difference, though someone here may have a scientific reason why copper is a better sheild.

2. The same person mentioned that the wires connecting the grounds on the pots are unnecessary.  Has anyone tried this as well?  Assuming that I do a good job with the conductive paint/metallic tape, it sounds like it should work.  I would of course test for conductivity with an ohm meter.  I always follow what the manufacturer says.
 
3. Does the pickup selector switch cavity need to be shielded?  No, it's not a must.

 

[greywolf]

Many builders use aluminum for Pickguard shielding so it isn't uncommon, I've used aluminum and rather than solder, I used a lead to a screw post.

A few tips :

  All of the shielding must be in contact with ground. There are several ways to apply a ground to a shielding network. When using copper shielding foil, the ground wire can be soldered directly to it. If your volume pot housing is in contact with the foil, a ground jumper to the foil is not necessary. Shielding paint  is also good for shielding control cavities, pickup routs, and drilled holes. The paint is very easy to apply in small tight areas, unlike self-adhesive foils.

It's easy to apply ground to a painted cavity, or an aluminum adhesive foil in a Strat-type guitar. Bring the paint or foil over the top of the body in the area that would be under the pickguard and around the pickguard screw below the bottom tone pot. The foil on the pickguard should surround this screw hole. When the pickguard is screwed into place, the grounded foil on the pickguard will come in contact with the cavity shielding paint. The same will work for a Telecaster control plate/control cavity and a Stratocaster jack plate/jack cavity.

Another method is the use of a solder lug screwed into the cavity's side wall. Make the solder lug out of a scrap of brass and use a small wood screw to affix it to the side wall. Just solder a wire from the volume pot's casing to this lug for a good ground.

 

[Patrick from Davis]

The shielding is just an electrically conductive material.  The shielded/ing paint is paint with graphite.  As long as you can ground the material it should behave just fine as a shield.  So Aluminum or copper will function the same in that regard.  As mentioned above, one may be easier to solder to, one may look better, so on.  One the pots, I have found that it is generally a good idea to sand an area and solder them to ground.  If for no better reason than I am sure it is grounded that way.  The shielding on the cavity can connect to it, but I really get frustrated with bad connections and weird noises (inconsistent grounding) which is probably something I acquired from building pedals.

With the concentric pots, I have found them to be conductive all the way through.  I soldered the ground to the back of it (the bottom pot)  I did a bunch of tests on my Tele with a 6 foot cord attached to the jack, used the sleeve for ground and a conductivity tester.  It is grounded...
Patrick

 

[Rick]

So there you go, "physically" (in the sense of physics) there's no difference between aluminium and copper foil.
You should ground the pots.
And it's OK to shield the selector cavity.

 

[GoDrex]

All I know is, aluminum works great at keeping the government's mind control rays out of my head.  :laughing7:

 

[SkuttleFunk]

R

 

[dbw]

"physically" (in the sense of physics) there's no difference between aluminium and copper foil.

Nobody said that... there are lots of "physical" differences between the two.  But for our purposes you're right... copper is a better conductor than aluminum, but both are plenty good enough to make an effective shield.

 

[ZGOZZ]

I use copper and shielding paint.

 

[Rick]

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Quote from: Rick on Today at 10:40:54 am
"physically" (in the sense of physics) there's no difference between aluminium and copper foil.


Nobody said that... there are lots of "physical" differences between the two.  But for our purposes you're right... copper is a better conductor than aluminum, but both are plenty good enough to make an effective shield.

Big D, it was pretty obvious, I meant in terms of sheilding ... but maybe you could explain which one is better for keeping out the government mind control rays. 
:headbang1: