Does brush-on shielding paint work?

[Old Deaf Roadie]

I am beginning a thinline build. After many very good results on other guitars, I am very partial to copper tape for shielding, but the cavity route on the body makes a taping challenge I don't look forward to or want to attempt. I see brush-on shielding paint from various sources and am curious about the actual efficiency of it. Any insight would be appreciated. Thankx!

 

[StrangerNY]

It's worked for me in the builds where I've used it.

Two coats are always better than one, allowing for full drying between coats.

- D

 

[SixStringSlinger]

I have a few guitars with it (stock; never applied it myself), and it seems to work fine. I have read some warning here about testing whether it's actually conductive from spot to spot within the guitar. No idea why it wouldn't be, but others here have warned to check that, whereas copper tape seems a pretty sure bet.

What makes taping so challenging in your case? I've applied copper tape in pretty tight spaces/corners and it's pretty forgiving about being smushed around and pressed flat. My greatest concern would be to wear gloves to make sure my fingers don't catch and edge while I'm pressing the tape in.

 

[tele_savales]

Yes, it works.

 

[warrent]

Try this water based version it's designed for wood and guitars
https://www.mgchemicals.com/products/conductive-paint/conductive-water-based-paints/emf-paint/

 

[Boreas]

I believe the key to using brush-on products is to mix, mix, mix. Keep mixing throughout the process. My guess is whatever is in there that is conductive settles out rather quickly. I use copper tape.

 

[trapdoor2]

I have used both. Paint is much easier to apply, copper looks cooler. I tested both, both seem to work fine in my applications (an HSS Strat and a Tele). Yah, I used two coats of the paint.

 

[Larry Mal]

Try this water based version it's designed for wood and guitars
https://www.mgchemicals.com/products/conductive-paint/conductive-water-based-paints/emf-paint/

I was coming here to say this. Not all shielding paint is the same, and that carbon stuff that Stew Mac sells is not particularly good.

That nickel or even better silver stuff that MG Chemicals sells is good, do at least three coats.

 

[KokoTele]

I have used copper and shielding paint for both my guitars and for my customer's guitars.

Tape is much more conductive and provides a better shield. However, over time the adhesive degrades and it doesn't always stay where you put it. (This happens over years, usually, as long as the surface was clean when you started.) Even in instances where the adhesive is conductive, I like to solder the overlap to make sure it's conductive for a long time.

Shielding paint requires several layers to become conductive enough to work well. I've measured resistance from a neck pickup cavity to the control cavity at over 100 ohms. That's enough resistance that it will still work, but not 100%.

In applications where it's tough to install copper cleanly, paint might be a less imperfect choice.

 

[magicfingers99]

It's worked for me in the builds where I've used it.

Two coats are always better than one, allowing for full drying between coats.

- D

as long as its high quality. its used in MRI coils for imaging humans using rf pulses. The stuff they use in the MRI coils is around 100$ a rattle can. copper tape is much cheaper...

 

[KelvinS1965]

I'm UK based, so my supplier will be different, but I used some from Charles Guitars and it's true that it needs a really good stir and two coats. Not necessarily thick coats, but to allow for it to properly dry between the coats as per the instructions.

I did measure mine with a meter and it was down to about 45ohms across the longest points, so I think that's pretty good. I initially did a Strat project I was working on because it has an active mid boost PCB under the 'guard too. Since done a Jaguar project and also my avatar Tele with it too (small pot but it seems to go a long way).

I refinished my MIM Jaguar from 3 tone sunburst poly to a home brew CAR. This was after buffing the clear coat and applying the second coat of conductive paint as shown in the picture:

 

[schmee]

With the price of it and the time to use it, I just dont use it. I'm not convinced it's as good as foil, but might be.

 

[KelvinS1965]

As I said I'm UK based, but this 60mL tin was only £7.50 (about $10?) and it's done 3 guitars so far.

https://www.charlesguitars.co.uk/pa...ar-conductive-shielding-paint-60ml-paint-only

The smaller 30mL tin is under £4 ($6?) and would probably do two guitars.

I think it looks neater than copper foil too, though since no one sees it I guess that's not important. Certainly comparing my two Strats the conductive painted one is much quieter (same active mid boost in both too).

 

[Billy3]

First off, don't do this on a guitar if you care about the value for resale on a vintage collectible instrument. Otherwise, use copper tape with conductive adhesive and have zero problems. With proper application you are good to go. I've put it in a couple guitars with pre existing shielding paint, because shielding paint just doesn't work as well, and it has made a huge difference. You just have to do every part of the inside and check with a multimeter. If you do a half arsed job, it will not work. My guitars are very happy and very quiet. Also realize there can be many things that interfere with your guitar making noises, electrical interferences can occur from many places. Shield it with the conductive copper tape and go from there.

 

[Old Deaf Roadie]

What makes taping so challenging in your case?

Too many blind surfaces, and part of the cavity is deeper than the length of my fingers. I don't mind melting angles into the plastic handles of cheap brushes to access, but the thought of a poor tape job just kind of bums me out & would drive me crazy if I knew it didn't meet my standards.

 

[KokoTele]

I don't think you need to shield the entire insides of that guitar to have effective shielding. Just shield a big swatch on the inside of the back and the underside of the pickguard.

The pots are already shielded by their cases, so you're just worried about shielding the switch and the pickup leads. And honestly, that little bit of exposed wire can't pick up that much RF.

The pickups themselves are much bigger culprits, since there's like 12 miles of wire wrapped around each of those bobbins. But if it has standard pickups, the neck is already mostly shielded, so that just leaves the bridge pickup.

 

[viking]

I dont give a foink about resale value , and it sounds like dirty electronics noise is a bigger problem in the US as where I live..... but , copper tape in all the caviaties ?
Nope , its just not needed
Conductive paint is ok
It just works !

 

[Jazzerstang]

Yes.

 

[montyveda]

I dont give a foink about resale value , and it sounds like dirty electronics noise is a bigger problem in the US as where I live..... but , copper tape in all the caviaties ?
Nope , its just not needed
Conductive paint is ok
It just works !

Stands to reason. My GS1 only has shielding on the inside of the plastic cover over the vol, tone and jack cavity. Never had any noise issues but it's only played in my sitting room... where it's surrounded by countless electronic devices.

 

[Peegoo]

Zombie thread!

I've tried the carbon paint, but I prefer copper tape. I get my copper tape from Delphi Glass (stained glass supply house).

My greatest concern would be to wear gloves to make sure my fingers don't catch and edge while I'm pressing the tape in.

You're using your fingers? Try this next time: a brand new pencil with a rubber eraser on the end. Wrap a layer or two of shop towel over the eraser and use that to 'scrub' the tape flat into full contact with the surface. It comes out looking like the cavity has been copper electroplated, and your fingers aren't all torn up.

I usually run a bead of solder all the way around the bottom corner of the shield to join everything together.