Can Aluminium tape work as a shielding tape ?

[Jam]

Would aluminium tape work for shielding tape for the guitar cavity? Thanks

[Bruce Johnson]

Sure, it will provide shielding.

One thing to watch out for: The copper tape that is sold specifically for doing shielding has a special adhesive on the back which is conductive. So, when you overlap two pieces, sticking one down on top of another, you'll get electrical continuity between them. Commercial aluminum tape, like you find in the hardware store, has a thicker non-conductive adhesive. So, have to be more careful and clever to make sure that all of your pieces of tape are electrically linked together. A typical way to do that is to fold a small ear of the upper layer underneath wherever you overlap, and then put a piece of clear packing tape over top to hold it down.

Also, some of the aluminum tapes have a slight clear coating on the upper surface which can interfere with the continuity with a wire or a part that you're trying to ground to. You might have to lightly scuff it to get that continuity. As with any shielding installation, you have to check it to make sure its all connected together.

[Mark Hammer]

Aluminum tape will stay shinier longer than copper tape (i.e., won't tarnish as quickly), but if you prepare the surface, you CAN solder directly to copper, whereas with aluminum it is unlikely. That will only have impact on use of the tape as a grounding point of convenience, though. For many people, the critical ground connections will be the pot chassis and jack, with the shielding tape only making incidental connection against the pots.

[David Schwab]

I've used aluminum for shielding, and then stuck a piece of copper tape with conductive adhesive to it and soldered to that. I have read several times that aluminum is better for shielding for reasons I can't recall.

[Chuck H]

I took the trouble once to shield a guitar with copper. Because I didn't have a source for copper foil at the time I had to buy some fairly heavy stuff at a stained glass supply shop (yes, I was surprised to find such a place existed too) and it cost too much $$$ and was a pain to use. Since then I have beed using plain old aluminum foil and 3M #77 spray adhesive. Prime the inside of the cavities so the adhesive will stick. The aluminum should be in one piece per cavity to be sure all the shielding is, uh, shielding. I trace the floor of the cavity onto the foil and then cut about two inces larger. Then slit the foil strategically so you can cover the cavity minimizing wrinkles. Be sure to overlap onto the body a tiny bit so that cover plate shielding will make contact. Now tap a small screw into each cavity and attach your ground to the screws.

Aluminum works dandy but the copper was better. There may be other reasons to use aluminum besides it's actual shielding effectiveness that I don't know about. It could be that aluminum oxidizes less with time and continues to make contact with the cover plate shields. Though my copper shielded guitar is still quiet after twenty years.

[Rick Turner]

3M makes tin plated copper foil tape with conductive adhesive.

But I use Electrodag conductive paint. Works fine, and it's easy. Just make sure to stir often, and use two coats.

[jrfrond]

Aluminum foil is better than nothing, but copper has superior shielding properties, which is why Faraday cages where critical RF alignment and troubleshooting is performed are lined with pure copper screen. I often do pickguard shielding with 3M #77 and heavy-duty Reynolds Wrap, which is cheap and readily-available, but I'll always use copper for cavity shielding.

You can't solder to aluminum, but a mechanical contact will work. Just make sure that you apply a contact protectant e.g. DeOxIt to the physical contact points to reduce the chance of galvanic reaction and subsequent contact failure.

[Bruce Johnson]

I used to shield my basses with copper tape, but it was just too much labor. The cavities in my basses are very complicated in shape. There also was the risk of having a piece vibrate lose and come in contact with something, causing an intermittent short. I had that happen at least once. There are ways to fix that, such as covering the copper tape with clear packing tape, but overall, it was all too much work.

For the last five years, I've been shielding all of my cavities with SuperShield, which is a spray paint containing nickel, made specifically for shielding. It works beautifully, has excellent conductivity, looks very neat and professional, and just takes a few minutes. All of my controls and wiring are built up onto an aluminum plate, which attaches down to the cavity, with multiple contacts with the SuperShield. It's simple and reliable.

[jrfrond]

I used to shield my basses with copper tape, but it was just too much labor. The cavities in my basses are very complicated in shape. There also was the risk of having a piece vibrate lose and come in contact with something, causing an intermittent short. I had that happen at least once. There are ways to fix that, such as covering the copper tape with clear packing tape, but overall, it was all too much work.

For the last five years, I've been shielding all of my cavities with SuperShield, which is a spray paint containing nickel, made specifically for shielding. It works beautifully, has excellent conductivity, looks very neat and professional, and just takes a few minutes. All of my controls and wiring are built up onto an aluminum plate, which attaches down to the cavity, with multiple contacts with the SuperShield. It's simple and reliable.

The only practical issue is that MG Super Shield might be a bit pricey for the one-time DIY user.

[dai h.]

Aluminum tape will stay shinier longer than copper tape (i.e., won't tarnish as quickly), but if you prepare the surface, you CAN solder directly to copper, whereas with aluminum it is unlikely. That will only have impact on use of the tape as a grounding point of convenience, though. For many people, the critical ground connections will be the pot chassis and jack, with the shielding tape only making incidental connection against the pots.

FWIW I tried spraying flux (a kind that comes in a spray applicator bottle which was described as useful for protecting copper) on to copper foil/sheet I put on the inside of an efx. enclosure(some goofy experiment), and it did seem to work and stay shiny (a lot of times copper can go dark or green which I guess is due to oxidation). Am a bit confused though because generally the recommendation is to remove residual flux (doesn't seem to cause any harm or weirdness in circuit operation except perhaps with super high impedance ciruits I gather). Also, I can buy adhesive-backed copper in small rectangular sheets, so if you can get it that way it might be easier than tape (or to use it in addition to).

oh and also, I think you can solder to aluminum (with special purpose made solder--something like that).

[Bruce Johnson]

The only practical issue is that MG Super Shield might be a bit pricey for the one-time DIY user.

Yes, a spray can of SuperShield costs about $40. In my experience, one can will shield about 20 instruments. I generally spray on two coats, about 10 minutes apart, and then let it dry for a couple of hours.

[Rick Turner]

Obviously it's best to make the job as complicated as possible for yourself. How else will you know whether you've done a good job or not? If it didn't take extraordinary effort, how can you be of any value? You must spend hours and hours on shielding; you must consider all the issues of galvanic reaction between different metals; you must research the most exotic of solders if you are going to use (inferior) materials like aluminum; you'd better consider the performance of shielding materials on up into the megaHertz range. Maybe you should use oxygen-free copper. Is it tin plated? Is the texture plain or quilted? Did you 100% solder the overlaps using SN 62 ( 2% silver ) solder? Have you star grounded everything?

Have you asked yourself what really matters and what doesn't?

[Chuck H]

Easy now. I took great pains to shield my #1 (home made strat-ish) with copper. One piece per cavity, taking great pains to keep it as wrinkle free as possible + pickguard + a wrap around each pickup over tape/under plastic cover. It did pay off in spades. I did some very custom series/parallel switching w/phase inversions that required a NON RWRP middle pickup and I don't have any trouble with noise. I think it's fully worth it for the DIYer to go the extra length and have something better than you can get almost anywhere. I'm not saying that there isn't a line to be drawn. There aren't any $50.00 tone caps in my guitar. I also didn't use silver solder. Fortunately I haven't had any trouble with the copper turning green and failing to make contact to ground the guard after almost twenty years. It is bar none the most non noise offensive strat I know of and the pain of doing it is old history that harkens back to a day when my compulsive nature could tolerate such tedium. Would I do it again... Hmmmm... Not so sure. But to do it once for your favorite is totally worth it IMHE.

[Steve Conner]

While we're getting OCD, I feel duty-bound to point out that the last four Faraday cages I worked in were made of steel. Copper is theoretically better, but it's a bit pricey to construct a whole room out of the stuff.

I once had a Gibson BFG Les Paul brought to me by a friend for shielding. The kind that look like Gibson were in a hurry and shipped them half-built. Cool looking guitar, and it actually sounded quite good, but it hummed like anything, especially when the kill switch was used. Shielding the cavity with copper tape made no difference, I had to replace the wires to the kill switch with shielded cable too.

If you have a guitar with single coil pickups, it's always going to hum, so you don't need to try too hard with the shielding.

[David Schwab]

Obviously it's best to make the job as complicated as possible for yourself. How else will you know whether you've done a good job or not? If it didn't take extraordinary effort, how can you be of any value? You must spend hours and hours on shielding; you must consider all the issues of galvanic reaction between different metals; you must research the most exotic of solders if you are going to use (inferior) materials like aluminum; you'd better consider the performance of shielding materials on up into the megaHertz range. Maybe you should use oxygen-free copper. Is it tin plated? Is the texture plain or quilted? Did you 100% solder the overlaps using SN 62 ( 2% silver ) solder? Have you star grounded everything?

Have you asked yourself what really matters and what doesn't?

Thanks for the laugh Rick!