Make your own Shielding Paint

[frets]

Hi Fellas,

I’m prepping another body I built and I thought why don’t I share this next step with all the Guitarnutz😇!!
Its my recipe for Shielding Paint and it is: 1. extremely effective; 2. cheap; and, 3. simple to make.  It costs about $10 and makes enough for about 3 guitars.  It has significant continuity and is very easy to apply.
It takes two ingredients;
- Graphite Lubricant Powder, and
- A Small Bottle of Black Water Based Acrylic Paint (any color will do, in my opinion, Black looks best).
You can find both of these at Walmart, the Graphite is in the Hardware Section and the Paint is in the Craft aisle.  
The Secret Formula is:
- 3 teaspoons of graphite powder
- 1 ounce of the water based acrylic craft paint.
Depending on the size of your guitar’s cavities, you may need to make a couple ounces of the mixture.
Be sure to mix it very thoroughly!! Mix Mix Mix!!  I use a plastic Solo cup and a plastic fork. (And I recycle them!)
Then, you just paint it into your guitar cavities with a 1/2 inch brush.  One good coat is all you need.  

Here I’ve done the cavities on a spalted I’ve built. You don’t need to do the neck cavity, I do that because I use threaded inserts (detachable neck settings) and I think it looks better in black.




I was just doing it and thought it might help someone out there.

[newey]

Good info,frets! I prefer to use copper shielding tape, but I also don't do anywhere near as many guitars as you do, so one roll of the tape last me for years and years.

I have had problems with shielding the output jack cavity "canoe" on Strats, and so I omit doing so, as the short run of wire is unlikley to be a source of noise.

I use a plastic Solo cup and a plastic fork. (And I recycle them!)

When it comes to plastics, there is a big difference between what is "recyclable" and what "actually gets recycled".Check with your local recycler, but in most places the only plastics that are actually being recycled at the present time are clear or white items. Colored plastics typically just end up in the landfills, as it is too costly to process them to remove the dyes, etc. and there is thus no market to recycle those materials.

So, probably better to reuse that red Solo cup for multiple shielding jobs . . .

[frets]

Hi Newey☃️

By “recycle” I meant “reuse” - just pulled out the wrong term. I’ve had the same red Solo cup for two years. Weeeee!!

I’ve been going back and forth between tape and paint. Right now I’m low on tape. I used it all on the Pickguard. Got low and then shifted over to making some paint.

The boat jack cavities are easier to do if you use 1/4” by 1/2” copper tape strips. Just cut your existing tape into smaller strips. Then just tape them in the best way one can and trim the ends.

[JohnH]

That's a great tip! thanks frets!

[thetragichero]

ahh that's cool actually have graphite powder from when the guy at ace misunderstood what i wanted to lubricate some open gear tuners

[unreg]

frets, thank you so much! 😀 This is excellent, I can now fully paint the cavity walls! 👍 They came only partially painted.

[unreg]

frets and all,

Went to a close Walmart yesterday.

1.) Powdered Graphite Lubricant was in the Automotive section. Though, the Automotive section was adjacent to the Hardware section... a kind clerk pointed me to the last 3-gram “handy puffer dispenser” they had. If anyone cares, it’s made by Hillman.

2.) After temporarily installing the Walmart app, I was able to find exact isle numbers for any item. The clerk said, “It’s usually right.” It also helped me learn that the close Walmart I visited did NOT carry acrylic paint. So, the nearby Hobby Lobby sold me a small 2 oz. tube of water based acrylic paint. It was less than a dollar! 😀 (That’s plenty bc I only need 1 ounce.)

[unreg]

Oops, 1 teaspoon is equivalent to something like:
2.362666666666667 grams (using calculator and an ancient dictionary to calculate this value)

... and so I need 7.088 grams instead of my 3 grams of graphite lubricant powder. 😔

Teaspoons are massive! 👍 I remembered that tablespoons were super giant, but forgot the size of a teaspoon. 😋

thetragichero, it’s also at ACE Hardware? (edit: Yes, it is! 😊) I’ll stop by there tomorrow.


Thank you again frets, this is quite fun! 😀

[thetragichero]

teaspoon is volume while grams measures mass. 1tsp = 5ml

[unreg]

Jan 9, 2021 2:26:48 GMT -5 thetragichero said:

teaspoon is volume while grams measures mass.

Hmmm... to me it doesn’t matter that one measures liquid and the other measures solid weight. I just wanted to know how many teaspoons I could fill with my small 3gram package.

The dictionary I used might have been helpful. Under “teaspoon” it has a note that:

1 teaspoon == 1 1/3 drams.

And under “measurement” it has an entire two page chart that contains (under weight):

1 dram == 1.772grams.


(What kind of people ever measured with drams? 😯😋)

So then I just used my phone’s calculator to arrive at that number of grams equal to 1 teaspoon. Hope my math turned out ok.

Regardless, that arrived at number made sense just looking at the size of a teaspoon compared to that small 3gram package. I didn’t have time today to visit ACE Hardware... maybe tomorrow. 🙂

[thetragichero]

dram is a measure of either weight or volume (i have heard it used in reference to whisky no e), confusing as it is
water-type liquids we can assume "close enough" density to water to convert between volume and mass (here is where the metric system is BRILLIANT 1 cm³ of water = 1 ml which weighs exactly 1 g)
graphite powder density 2.2 g/cm³
water density 1 g/cm³

so if you are given a recipe (let's say you're baking a cake), and asked to use 1 tsp of salt (density 2.165 g/cm³) you best not do weird conversions to weight based on the density of water or your cake is gonna taste horrible

(there may be folks here better equipped to explain. not as good of a teacher as i am a doer hell of a baker though)

[thetragichero]

cool thing to with keeping units of measure equivalent is that they're a ratio anyway, so you can adjust based on what you have vs what you don't

3 tsp (1 Tbsp would be more efficient) graphite powder to 1 fl oz paint
so 15ml graphite powder to 30ml paint (technically 29.574ml but what's less than half a ml among friends?)
hey that's 1:2 ratio!
other cool thing about ratios is that you can measure out based on what's handy. cap from a plastic water bottle is likely handy (would the hippies have called that a "lid"?)
shot glass if you're feelin frisky
spoon from your silverware drawer would work if you remember to wash it well before putting it back
the possibilities are endless!

[newey]

Jan 10, 2021 0:03:04 GMT -5 unreg said:

What kind of people ever measured with drams? 😯😋

Apothecaries did. Nowadays we call them "Pharmacists"

The idea of shielding paint is that it be electrical conductive. So, whatever amounts you use, you can simply test with your meter after it has dried to see if you have conductivity from point-to-point across the painted portions of your cavity. If not, you used too little graphite in your mix. If you have enough material left, a second coat might do the trick as well.

[unreg]

Jan 10, 2021 4:17:43 GMT -5 thetragichero said:

dram is a measure of either weight or volume

Cool! 😀👍

Jan 10, 2021 4:17:43 GMT -5 thetragichero said:

confusing as it is
water-type liquids we can assume "close enough" density to water to convert between volume and mass (here is where the metric system is BRILLIANT 1 cm³ of water = 1 ml which weighs exactly 1 g)
graphite powder density 2.2 g/cm³
water density 1 g/cm³

yes, the metric system is excellent!

Jan 10, 2021 4:17:43 GMT -5 thetragichero said:

so if you are given a recipe (let's say you're baking a cake), and asked to use 1 tsp of salt (density 2.165 g/cm³) you best not do weird conversions to weight based on the density of water or your cake is gonna taste horrible

This is what they taught in Chemistry and/or Physics... never convert between weight and volume; otherwise, your cake will taste horrible. Not exactly as you explained, but I’ve received that idea before.

However, since drams can measure volume OR weight, I believe I wanted to only think of a teaspoon in its weight measurement. (i.e. PRETEND it NEVER ever ever was used to measure volume.) Therefore my calculation doesn’t, I think, ever ruin cake tastiness bc it’s a calculation based solely on weight.

Jan 10, 2021 4:17:43 GMT -5 thetragichero said:

(there may be folks here better equipped to explain. not as good of a teacher as i am a doer hell of a baker though)

To me, you are a great teacher bc you are extravagantly skilled and you teach through pictures! 😀

[unreg]

Jan 10, 2021 9:13:20 GMT -5 newey said:

Jan 10, 2021 0:03:04 GMT -5 unreg said:

What kind of people ever measured with drams? 😯😋

Apothecaries did. Nowadays we call them "Pharmacists"

The idea of shielding paint is that it be electrical conductive. So, whatever amounts you use, you can simply test with your meter after it has dried to see if you have conductivity from point-to-point across the painted portions of your cavity. If not, you used too little graphite in your mix. If you have enough material left, a second coat might do the trick as well.

Thank you newey! 👍😀

[solderburn]

This is so cool! Thank you, Frets, for sharing your secret recipe! I'll definitely be using this on my next build. 

[unreg]

Dear frets,

Just checked the capacitance of my painted cavity with my meter, as newey suggested, and the entire black cavity returns OL.

Dec 21, 2020 16:00:43 GMT -5 frets said:

Be sure to mix it very thoroughly!! Mix Mix Mix!!

I am wondering if I didn’t mix the mixture thoroughly? Maybe the graphite lubricant powder didn’t mix completely... hmmm. How long do you mix yours?


Also, my graphite lubricant powder has a bit of quartz in it. Does that matter? I figured that the quartz and 1 other extra material was part of all powdered graphite lubricant. What brand do you use? Mine might be by AGS.


I marked a clear plastic cup after pouring about an ounce of water in. (Couldn’t measure exactly 1 ounce; here, both measuring cups begin their marks at 2 ounces.) Then I emptied, dried, and filled that cup with about an ounce of water based acrylic paint. Next, I followed thetragichero’s advice, and filled a tablespoon with that powdered graphite lubricant. Didn’t use a knife to flatten the tablespoon, bc I was being lazy. 3 tsp == 1 tbsp. ✅


Please poke whatever holes in my preparations. I’ll make a second coat, but want to be sure to avoid any mistakes I’ve already made.

[thetragichero]

i wouldn't expect a capacitance reading. how about a resistance reading?

[frets]

Hi Unreg ,
First, I’m sorry your having trouble with it.  You’ve followed the recipe perfectly.  3 teaspoons of graphite powder to one ounce of Acrylic paint. The only thing I can offer is that I use a particular brand of graphite powder, AGS.  Here’s a pic.

But I would not think other brands would cause a problem.  I don’t k ow about the quartz.  I haven’t been too helpful, all I can say is using the AGS graphite, my cavities are quite conductive.  

[unreg]

frets, thank you! 🙂 That is the exact AGS package that I found at ACE Hardware. On the package’s back, it says, “CONTAINS: Graphite, Mineral Ash, Quartz”. Happy to learn we are using the same powdered graphite lubricant! 😁

thetragichero, thank you! 😊 I made a mistake, my meter was actually measuring Continuity. I had received a Continuity OL around the entire cavity, guess bc the resistance was never low enough to be read in that mode. However, after setting my auto-ranging meter to measure Resistance tonight, after reading your knowledge, I received readings everywhere: from 43k ohms to 2.1M ohms. Does that resistance mean that the black paint/graphite mixture is conductive?

(In my weird head, capacitance seems closest to conductive. Maybe your reply was kind of like ReTrEaD’s use a clothing iron reply. I’m torn between accepting your help or appreciating your joke. How is resistance conductive? 🙂)

[thetragichero]

not conductive enough for me, no

[newey]

Jan 19, 2021 22:33:44 GMT -5 unreg said:

How is resistance conductive?

Conduction happens when there is a lack of resistance. thetragichero wasn't joking.

ashcatlt once said here that every point in the Universe is electrically connected to every other point- You just need enough power to overcome the (huge) resistance between the two points. I thought that was a particularly perceptive observation.

Air, for example, is a poor conductor, but if the voltages are high enough, electricity can be conducted through air. The ignition in your car needs to produce around 40Kv just to cross the gap between the electrodes of your spark plugs, which is about 1/8 of an inch. A bolt of lightning needs millions of volts to cross the gap from ground to clouds.

[unreg]

Jan 20, 2021 6:50:42 GMT -5 newey said:

Jan 19, 2021 22:33:44 GMT -5 unreg said:

How is resistance conductive?

Conduction happens when there is a lack of resistance. thetragichero wasn't joking.

ashcatlt once said here that every point in the Universe is electrically connected to every other point- You just need enough power to overcome the (huge) resistance between the two points.

newey, thetragichero, ashcatlt, Thank you all so much! 👍😀 Conduction makes perfect sense now! 😁 I must have added to much paint or not have mixed enough. I’ll definitely repaint my cavity. And, I’ll measure a test mixture applied to a spot for Continuity before creating the ounce of paint mixture.

[ashcatlt]

Conductance (G) is literally the inverse of Resistance. R = I/V. G=V/I=1/R. The unit is officially siemens, but a lot of people say “mho”, which is just “ohm” backwards.

[unreg]

Jan 20, 2021 0:53:25 GMT -5 thetragichero said:

not conductive enough for me, no

Just repainted, and now the resistance reading is between 14k ohms and 8k ohms. thetragichero, is that conductive enough for you? (The paint is still wet inside my cup of paint so I can add even more powdered graphite lubricant and repaint.)

frets, is a resistance reading of between 14k ohms and 8k ohms conductive enough? Or repaint again? 🙂

[thetragichero]

nah you want small small resistance. much smaller than 1k. closest to zero ohms as possible. maybe you didn't follow the "mix mix mix" instructions well enough?

[newey]

Last time I checked copper shielding across a Strat cavity (and across a few seams as well) I got 9Ω. Not 9K, just 9. Your shielding paint may not go that low, but it should be a lot closer to that than thousands of Ohms.

I use the copper tape with the conductive adhesive, this eliminates having to fold it over at the seams.

[frets]

Unreg,

I average around 11 ohms with this method. I’ve been able to paint a strip of it on a piece of cardboard and light an led with it to show to the kids. I don’t know what to tell you.

[newey]

unreg-

Are you sticking pointed probe ends into the wood cavity to do the measurement? Possible that you are going through the paint if so. Try laying the probes more horizontally across the shielding, maybe tape them down if you need to. Or use wires with alligator clips between the probes and the cavity.

And, if the underside of your pickguard is shielded, test that as well, just to be sure it isn't an issue with your meter. (also, touching the probes together should read right around 0 Ohms).

[unreg]

Hi all! Thank you for responding! 😊

I ended up adding even more powdered graphite lubricant, repainting, and now, after quickly measuring 2 points, the average resistance is much smaller... it’s a maximum of 1k. Though, I need to measure Continuity bc, my meter will beep if it reads less than 50 ohms. I gave up on Continuity since it never beeped. Now I’ll try again since my reading should be as closest to 0 as possible. Not going to measure Continuity bc I’m only supposed to be measuring resistance. Sorry, just watched the “how to use a multimeter” thread’s video.

And newey, thank you for that using wires connected to the alligator clips suggestion! 😀 I believe you’ve suggested that before; it’s much better for me bc the probe points sometimes make scratches; scratching painted surface feels awful. I’ll report back with measurements.



edit: newey, my guitar doesn’t have a pic guard; everything is accessible from only the back. 😔