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"Shielding Paint" is often just crap. StewMac Video.

Discussion in 'Tech-Talk' started by vid1900, Jun 13, 2019.

  1. vid1900

    vid1900 Most Honored Senior Member

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    When I tell people with buzzy guitars that they need some real copper foil shielding, they often counter that "It has shielding paint inside!".

    But if they ever removed the grounding lug from the cavity, it often will never again make an electrical connection when re-installed.

    Or if it's an Asian guitar, often it's just black paint, with no conductivity at all.

    You can see the scam here:


     
  2. vid1900

    vid1900 Most Honored Senior Member

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    A couple of notes on the above video.

    1. Waiting for 3 coats of "real" conductive paint to dry is silly. Get a big roll of Copper Tape from eBay for $3. It will be conductive today or 100 years from now - you can even solder to it.

    http://rover.ebay.com/rover/1/711-5...0001&campid=5338148356&icep_item=292567332546

    2. No need to shield the entire pickguard (like she did the lower horn). That's a big waste of materials. Just shield above the electronics.

    3. Make sure a tab of copper tape extends out of the cavity and under one of the screw holes - at both the Jack Plate, and the Pickguard. This ensures an electrical connection to both of those items.

    4. Test your work with a Volt Meter. The tape's adhesive is normally conductive, but if any section is not, just solder the tape to the rest of the shielding.

    5. Make sure your cord tip does not short out against the shielding around the Jack Plate.

    6. Your guitar should now be equally quiet with your hands on or off the strings.
     
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  3. Believer7713

    Believer7713 Most Honored Senior Member Silver Member

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    I have a question about doing some shielding on my current build. I am not for sure how it will work with this set up so I need to know if it will be a wast of time or if I will actually benefit from shielding it. The guitar is being wired with an EC mid boost circuit and has Fender Hot Noiseless p'ups. Will it be a waste or should it be helpful?
     
  4. Yves

    Yves Most Honored Senior Member

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    I supose I stroke lucky then
     
  5. Ronkirn

    Ronkirn Most Honored Senior Member

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    If you have Humbucker's or noiseless pups.. shielding will be a waste.. however.. if anyone in the future ever looks inside, and its all copper, they will be impressed.... so sign it too.. :p
    r
     
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  6. Johnny Danger

    Johnny Danger Senior Stratmaster

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    I thought long and hard about this when I was trying to see if I could make my AVRI a little less noisy. I was hesitant to mess with something that worked really well and I wasn't excited about doing something potentially irreversible to a clean stock 20 year old guitar. I weighed both options and eventually came to the conclusion that what seem to be people in the know point to the massive antenna that is a single coil pickup. It is going to grab any noise it can regardless of how meticulously and methodically you shield the cavity it's sitting in. So I didn't bother. I also looked up some pre/post shielding comparison vids and it seemed to make little to no difference in those examples.

    I did try a dummy coil, which did make it dead quiet, but also made it sound like a weak humbucker. So now it does its duty in pure stock form and it's a beautiful thing.
     
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  7. vid1900

    vid1900 Most Honored Senior Member

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    A good test of "Will shielding make any difference for me?" is to take your hands off the guitar with the volume up.

    Did the hum increase? Then shielding could help.

    Did the hum stay the same? Then it's probably already shielded as well as it can be.

    Sometimes a circuit board inside the guitar will hum if it is facing a computer monitor or LED ceiling lamp. You can shield to avoid most of this too.
     
  8. Yves

    Yves Most Honored Senior Member

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    All I can say is that it worked superbly well for me. Here is the detailed work scrolling down that thread.
    The result is absolutely brilliant!
     
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  9. vid1900

    vid1900 Most Honored Senior Member

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    One place is hard to shield with paint or foil is the wire lead to the Jack Plate.

    This pair or wires is exposed to RF for that couple of inches from the controls to the Jack.

    Here, you can see that a piece of Shielded Wire was used, rather than 2 single leads:

    14-output-jack-lead-wire-soldered.jpg

    If for some reason this was unwanted (like a "vintage" guitar), you would twist the two leads evenly together for the length of their run.

    This "rejects" hum much better that straight leads:

    telecaster-13.jpg
     
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  10. vid1900

    vid1900 Most Honored Senior Member

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    Here you can see the tabs of Copper Foil that I have extended out from the cavities and into the screw paths.

    This will allow the body shielding to connect to the scratchguard shielding.

    IMG_20180316_115523236_HDR.jpg

    One good thing about Copper Foil vs Conductive Paint is you can remove it latter.

    So if 70 years from now your guitar is worth a zillion dollars, your grandkids can remove the foil and return the guitar to 100% $tock.
     
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  11. Believer7713

    Believer7713 Most Honored Senior Member Silver Member

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    This is the wire I like to use since I like push back style wiring.
    [​IMG]
    Plus, it's really easy to solder cleanly.
    [​IMG]

    Sent from my SM-G975U using Tapatalk
     
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  12. Groovey

    Groovey Most Honored Senior Member Strat-Talk Supporter

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    All good stuff. I just paid for a small handful of copper tape from a popular site. Dang my luck. Always consult the forum, always consult the forum....
     
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  13. Andrew Wasson

    Andrew Wasson Senior Stratmaster

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    I would think helpful. I’m not sure how much the noiseless pickups need help but unless you’re using shielded cables there are opportunities for the wiring to induce buzz or hum.

    I use HVAC aluminum tape. A roll is pretty inexpensive and the adhesive conducts so no need to worry about attaching one piece to another. If they are touching, they are conducting. I did my Squier Series and my Telecaster. They are quite quiet as a result.

    Photos:

    E65C6B7E-4A18-407F-B8C4-1C3B3315FC26.jpeg

    I didn’t have photos of the Telecaster handy but this is a BC Rich Warlock I did recently. It has humbuckers but I split them on a push/pull tone control pot so I wanted it to be quiet.

    38BA5AED-7C1F-47B6-B2D1-3EA76862B99B.jpeg 4A189579-8C59-491A-A87D-B6A45DA8F007.jpeg
     

    Attached Files:

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  14. simoncroft

    simoncroft Dr. Stratster Strat-Talk Supporter

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    Great thread!

    I've tried most methods of reducing RF interference in Strats - copper, aluminium and conductive paint – and they all work to an extent. None of these methods work unless you've formed a 'Faraday Cage' by connecting all your shielded surfaces to Ground (Earth). Big thanks to @vid1900 for pointing that out, because it's essential.

    @Raimonds created an induction loop for his Tele, which works even better. However, it's either a non-reversible mod, or means you have to cosmetically change your guitar.

    I shielded my 86 MIJ Strat with adhesive copper sheet. Worked pretty well, but the sheet could cut like razor blades! Although I assume the thicker copper might equate to better shielding, I have no science to back that up.
     
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  15. Ronkirn

    Ronkirn Most Honored Senior Member

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    the overall thickness of the material chosen will have no appreciable effect on the degree to which interference is shielded, but you must be certain there is conductivity between each and every piece used to achieve the Faraday Cage Simon speaks of... that means the adhesive on the metal tape must be conductive, or you must connect each piece, either by soldering, or making a mechanical connection with a screw and a piece of wire...., other wise its just decoration..

    I'm afraid the HVAC aluminum tape will require the point to point screw and wire method, ya cannot solder aluminum..

    Here the adhesive is conductive, and that's backed up with solder points... I'm a bit excessive like that.

    r


    DSC_6910.jpeg
     
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  16. JB74

    JB74 Senior Stratmaster

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    If you have an old Jazzmaster, you need not worry. They had brass shielding inserts, just like 335/345/355 had shielding covers over the pots.
     
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  17. Andrew Wasson

    Andrew Wasson Senior Stratmaster

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    HVAC adhesive conducts. I discovered this while doing a bunch of duct work. I wondered if the adhesive would conduct from the steel I was taping it with and yes indeed the continuity was absolute with negligible resistance. That’s one of the reasons I chose it over copper. The other reason was because Bill Lawrence recommended it in his research papers on the subject.

    And yes, grounding the cages a must if you want it to do anything positive.
     
  18. amstratnut

    amstratnut Peace thru Music. Strat-Talk Supporter

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    I tried copper tape and it sucked. You guys make it look great.

    My solder barely stuck to the copper. The tape wasnt sticky enough to stick to the cavity. It kept popping up. Once it was in place I could barely fit pups back in.

    I cut my fingers to ribbons....that sh!t is sharp.

    I said eff it and took it out.

    I do like foil on the back of the pg.
     
  19. vid1900

    vid1900 Most Honored Senior Member

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    Solder needs 3 things:

    1. Clean Copper (any coatings, oily films or oxidation have be removed)

    2. Flux - You need the chemical reaction or its a no go. Old "flux core" solder might not be too fluxy anymore (that's why flux core has an expiration date), but Solder Paste for circuit boards works like magic. (we use DeoxIT Rosin Soldering Flux)

    3. Ample Heat - all that copper is a giant heatsink, you need enough heat to wet-out the solder.

    Don't use lead-free solder, don't let anyone tell you "they don't make it anymore" (they do, so you can service old leaded circuits), get the good stuff = Kester "44" SN63/PB37
     
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  20. hobdybob

    hobdybob Strat-Talk Member

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    when i read this form Bill Lawrence: http://billlawrence.com/Pages/All_About_Tone.htm/TeleLovers.htm

    made me change my shielding method, because in this article it mentions the aluminum and its high eddy current potential.
    so i tried a dual foil shield.
    all above an surrounding the pickups is copper, controlcave is alu.
    because the copper i used had bad conductive adhesive i put some small pieces off alu that has good conductive as overlay to connect them, still grounded the pots with wire.

    first impression, no bad influences in sound and seems to be more silent.
    please don't look at the not so neat placement of the foil, it was just a quick test

    [​IMG]

    [​IMG]
     
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