Conductive shielding paint!

[Kain VKail]

so i bought this stuff and i think it was a good idea...i hope it was. but how should i apply it. and when applying it what should i be wearing.

Can i do it outside instead of in a garage because all i have is out side to do any work.

And when im done how should i let it sit to dry. can i leave it in my basement? i cant do the work there with the opened container because its not very well vented.

 

[Cagey]

so i bought this stuff and i think it was a good idea...i hope it was. but how should i apply it. and when applying it what should i be wearing.

Can i do it outside instead of in a garage because all i have is out side to do any work.

And when im done how should i let it sit to dry. can i leave it in my basement? i cant do the work there with the opened container because its not very well vented.

Since you already have the stuff, we'll skip the discussions about its efficacy.

Applying it is as easy as painting anything you'd paint with a brush. Just brush it on. It's never going to be seen, and pickup/control cavities don't have good surfaces anyway, so don't worry about brush stroke marks or anything like that. Use a narrow brush, maybe 1/2" to 3/4" wide.

The stuff I'm familiar with is water based, so clean-up isn't a problem. Kitchen sink works fine, if you have running water <grin>

Don't worry about ventilation - there are no combustibles or VOCs involved. Treat it like latex interior house paint.

It's a little thinner than house paint, so don't try to glop it on too thick - it'll run and puddle. Better to do several coats instead.

Let the body sit flat to dry.

As for what to wear, I'd get some nice Calvin Klein designer jeans, a ruffled white shirt with black piping like you'd wear with a wedding tux, and some high-top Raeboks for your feet. Get a pair that black won't show up on so easily, such as these...

Or, you could just wear anything that you don't mind getting paint on. Unless you're some kind of clumsy animal with little motor control and no opposable thumbs, I can't imagine you'll have much of a problem with that anyway <grin>

Actually, since you can apply it indoors without any problem, you don't necessarily have to wear anything at all. Paint it, clean up your brush (or just throw it away), and go take a shower. You'll be fine.

 

[Kain VKail]

well im quite partial to the idea of the wedding tux. thats actually how i do some of my best work.

but what do you mean abou the efficiancy. is there something better? i mean id be willing to get that instead so i dont feel really stupid later.

 

[line6man]

well im quite partial to the idea of the wedding tux. thats actually how i do some of my best work.

but what do you mean abou the efficiancy. is there something better? i mean id be willing to get that instead so i dont feel really stupid later.

There is no need to discuss this yet again, but Cagey feels that shielding is a complete and utter waste of time and money because it does nothing.
Personally, I feel that shielding is largely useless, though in some applications has proven to make a big difference, but there is no excuse not to just shield your guitars either way.

FWIW, make you sure stir the paint frequently. Conductive paint is not as conductive as copper tape, as it's just conductive material suspended in paint. You don't want the conductive material settling.

 

[Kain VKail]

so what in the world should i do i mean i have a bunch of copper shielding that i bought from warmoth and every luthier i talk to says its useless and then now you guys tell me that the paint is basically useless. im new to this building process so itd be great to have a solid idea of what basically the most appropriate choice/application to my problem.

 

[line6man]

so what in the world should i do i mean i have a bunch of copper shielding that i bought from warmoth and every luthier i talk to says its useless and then now you guys tell me that the paint is basically useless. im new to this building process so itd be great to have a solid idea of what basically the most appropriate choice/application to my problem.

I would just shield the guitar for the hell of it.

 

[Cagey]

but what do you mean abou the efficiancy. is there something better? i mean id be willing to get that instead so i dont feel really stupid later.

I said "efficacy", not "efficiency". Efficacy is the capacity to produce an effect. Efficiency describes the extent to which time or effort is well used for the intended task or purpose. See any dictionary or the Wiki.

The efficacy of cavity shielding in a guitar is nearly non-existent, which means that there can be little or no measure of efficiency.

But, to make a long story short, it doesn't hurt anything, and if you take pictures while building, it makes for more attractive cavities.

If you really want to eliminate as much external influence on your signal as possible, you have to shield the signal conductors themselves. Do that well, and you can forgo all the conductive paint and/or copper business. Bear in mind that if you're using single coil pickups, most of your shielding efforts will be in vain anyway. But, hope springs eternal, so do what you think is best. As I said, it can't hurt.

 

[Wana_make_a_guitar]

so what in the world should i do i mean i have a bunch of copper shielding that i bought from warmoth and every luthier i talk to says its useless and then now you guys tell me that the paint is basically useless. im new to this building process so itd be great to have a solid idea of what basically the most appropriate choice/application to my problem.

I would just shield the guitar for the hell of it.

Agreed, what have you got to loose (apart from a tux and some raeboks). If it works, HAZZAH! If it doesn't work, you've got a nice pretty control cavity that's now worth slightly more.

 

[Cagey]

so what in the world should i do i mean i have a bunch of copper shielding that i bought from warmoth and every luthier i talk to says its useless and then now you guys tell me that the paint is basically useless. im new to this building process so itd be great to have a solid idea of what basically the most appropriate choice/application to my problem.

It's not Warmoth's, Stewart-MacDonald's, Luthier's Mercantile's, or any other vendor's fault. They sell what people demand. They're not engineers or in the business of making value judgements on your part. Some guys think copper shielding or conductive paint works, so they sell the stuff. Who wouldn't? It's not dangerous and it doesn't hurt anything. They also sell purple paint, Bigsby vibratos, and Kluson tuners. Go figure.

The thing is, you're trying to create what's called a "Faraday Cage". You surround something in a conductive enclosure, then ground the enclosure, and no external EMI/RFI can get in. Where it becomes a problem is if there are any holes in that enclosure, it's as if the enclosure isn't there. It's like a submarine with screen doors, only worse because interference moves at the speed of light, and once it's in it bounces around. Any other conductors it encounters will have signal induced at the frequency of the interference.

Well, guess what? You have anywhere from one to three huge holes in your cage where the pickups poke out. Can't help that. What's worse is the pickups themselves are effectively very large antennae tied to a high impedance amplifier input. They're so sensitive they want to pick up signals from Alpha Centauri. So, you have huge holes with monster antennas sticking out - what good do you suppose shielding behind all that is going to do? You may as well bark at the moon.

 

[crash]

Cagey's theory can be demonstrated at home.  Just build a relatively high gain pedal, then remove the screws for the cover.  Slowly open and close the cover.  You will notice that as soon as the cover is opened just a sliver (~0.5mm) you will get a buzzing sound.  That is the Faraday cage being rendered useless.  Put the cover back on all the way, the buzzing goes away (mostly).

One good way to eliminate noise, Make sure your amp is plugged into a circuit with no dimmer switches or fluorescent lights.

 

[Kain VKail]

ok this is all starting to make a lot of sense. but since ive already bought it im just going to use it because it looks splendid even though no one will see the inside of the cavities.

 

[Cagey]

That's why I said early on that we wouldn't discuss it because you already spent the money. May as well use the stuff - it's not expensive, it looks good, and it doesn't hurt anything. But, now you understand why it's useless as well, so it's all good. You won't make the same mistake twice.

 

[Strat Avenger]

well im quite partial to the idea of the wedding tux. thats actually how i do some of my best work.

but what do you mean abou the efficiancy. is there something better? i mean id be willing to get that instead so i dont feel really stupid later.

There is no need to discuss this yet again, but Cagey feels that shielding is a complete and utter waste of time and money because it does nothing.
Personally, I feel that shielding is largely useless, though in some applications has proven to make a big difference, but there is no excuse not to just shield your guitars either way.

FWIW, make you sure stir the paint frequently. Conductive paint is not as conductive as copper tape, as it's just conductive material suspended in paint. You don't want the conductive material settling.

I remember reading a long time ago on The Gear Page that John Suhr strongly disagrees that shielding does nothing. He claims that people just don't know what they're doing -- including mass-production guitar manufacturers.

All I know is; I used the shielding paint, shielded cable from the volume pot to the output jack, and twisted wires from the switch to volume pot. The pickup wires are shielded. I didn't notice any real reduction in noise (although there isn't a lot since the pickups are humbuckers).

Also, the EVH Wolfgang guitar has no cavity shielding whatsoever, and it's an expensive guitar with his Seal Of Approval.

 

[Strat Avenger]

That's why I said early on that we wouldn't discuss it because you already spent the money. May as well use the stuff - it's not expensive, it looks good, and it doesn't hurt anything. But, now you understand why it's useless as well, so it's all good. You won't make the same mistake twice.

A quart from StewMac cost me $30. Not exactly cheap.

 

[Kain VKail]

well i think at this point its all speculation. maybe mr suhr is right. i mean he does make some of the finest and greatest sounding guitars in the world. but eddie, even though he did have luthier work with him on his new guitar line, just likes to toss stuff together until it sounds good. but i will say he is quite the innovator, regardless of him actually having a methodical plan or not for most things he does.

either way ive already started. it looks decent so im going to move forward with it. i think we can nix this thread. thanks everyone

 

[Cagey]

A quart from StewMac cost me $30. Not exactly cheap.

Geez! I didn't realize it cost that much. I was under the impression it was only $5-$7.

 

[Super Turbo Deluxe Custom]

A quart is enough to shield every guitar you and all of your friends have or will ever own.  The paint, depending where you keep it, will go bad before you ever use it all.  $30 may seem like a lot, but that's just the particular increment size you bought.  25 to 50 cents of it is actually going in the guitar, so it is relatively cheap.

I was in a surplus electronics store in a warehouse district a while back.  A guy came in looking for some to shield the plastic shell of a desktop computer.  The employee recommended chrome spray paint and sent him on his way, making no mention of grounding the sucker.  Grounding cavities is essential for the process to work.  Even when not intentionally, mechanically grounding, just assembling often causes effective incidental grounding.  Let's hope that happens with this guy, and that spray paint is conductive enough.

 

[Jusatele]

I will finally interject here,
If we shield something from electrical  interference we shield it from all the way around, and then we filter the entrance to it, such as a radar system. A guitar has a huge area we can not shield, the area under the strings, we need this area to pick up the strings to make the electrical field to create the signal to go into the amp, so shielding may help in any area not under the strings, but does not eliminate unwanted interference as the entire top section of the pickup needs to be unshielded and then can pick up any interference. and no guitarist in the world stands perfectly still.  
I applaud the efforts of those who shield, but as with any idea they really go to far, the pickup is the area needing shielding, not the control cavity, unless you use twisted wire which in itself is a transformer. unshielded twisted wire is a transformer. put current through a wire with another wire twisted around it and it will create eddie current.
SO, does shielding a cavity work, YES, but very little unless you seal it entirely in, other wise it works, but only very little, that may be enough for some, but I do not bother as I mainly use single coils and I accept the fact that they are noisy, a lot of my technique in playing and my muting is to eliminate the sounds. As you grow in playing you also learn techniques you can not even describe to hush sound. I am always plying with the volume not even knowing it anymore and I can mute 5 strings, how, I do not even know how to describe it I do it automatically bit it is a 2 hand technique. the only guitar I own with a humbucker is my 335, and my fretlight, but is a fretlight really a guitar or a practice device ? I mean get real would you take a fretlight up on stage, unless the fret board is lit it is useless, the pickups suck.
I think we are looking for the holy grail here, but it is not what we can build, it is what years of playing teach us, and a lot of that is this

a amateur practice till he makes no mistakes

a professional practices ti he cannot make a mistake

bottom line, the search for noise abatement, the search for tone, the search for technique all boil down to how many hours do you put into chopping wood a day, Just my warm up finger exercises are 10 minutes of 16th notes at 120 bpm, then I do finger stretching exercises for 5 minutes, then I play at least 1 hour a day and I consider myself about in the middle of my peers, some of the guys I play with are so insanely fast I just close my eyes and try to out soul them with my ability to create emotion in my playing. it is my way of keeping up with the guys who practice at levels I cannot even achieve.