(Anecdotal) MythBusters - Does Copper Tape Actually Fall Off?

[DiabolusInMusic]

One commonly mentioned con against using copper tape for shielding is that the copper will lose it adhesive over time and come loose. I have repeated this myself. I know some of you have repeated it too because I learned it here.

I have pulled some jobs done years ago, both copper and aluminum, and did the jobs again with paint. While I do not recommend aluminum, I never saw even the slightest sign of peeling with either tape. I have never used aluminum tape on nitro. The jobs were no more than five years old and I live in a very dry climate, so it wasn't the worst of conditions for the tape.

I realize this is not a scientific study of any kind but I am wondering if anybody has actually seen copper tape peel inside of a cavity. I am not referring to a bass that went through a flood or anything either, just plain old playing wear and tear.

 

[megafiddle]

The "peel and stick" type adhesives on copper tape, velcro strips, etc, seem to hold well for many years on
nonporous surfaces. I have seen adhesives of this type fail on bare wood though, sometimes in just months.

A cavity surface, if clean and painted, should not be a problem.

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[gpx1200]

I allways try to make shure the cavitys have a good smooth coat of paint in them exactly for that reason

 

[Bruce Johnson]

I have personally had copper shielding tape come loose inside basses I've built, causing erratic shorting problems. More than once, which is why I stopped using it. The problem was always the same thing: the adhesive wasn't strong enough to stick to a painted wood surface that any significant roughness to it. The particular problem was the routed side walls of the cavities. They were routed smooth, and had several coats of base finish on them. But any little bumps or dust or rough grain would prevent the adhesive from sticking down fully. I opened up instruments that were less than two years old, and the copper tape on the side walls was loose and wiggling around. I finally resorted to putting a layer of clear 3M packing tape over top of the copper tape, as an insulator, to make sure that it couldn't short out if it came loose. I fought with the tape for several years and gave up on it. I found ways to get it to stay in place, but it was still too much work to put in. The cavities in my basses are more complex than average.

The SuperShield paint is so much faster and appears to be completely reliable. I've been using it in all my basses since about 2005. I haven't seen any evidence of it flaking or chipping, or anything. The black Stew-Mac paint would flake off the walls over time. I've opened up basses I shielded with the Stew-Mac paint back in the '90's, and found small piles of conductive black powder in the control cavity. Not good.

The copper tape is fine for flat smooth surfaces. I still use it for shielding areas on the undersides of pickguards, or the backsides of plastic control cavity covers.

 

[khutch]

I've had a lot of trouble with peel and stick Velcro failing on my telescope gear, even the stuff with the "industrial strength" adhesive. But telescopes live a much harder life than most bass guitars, they will be outdoors during the dead of winter and the hot, humid peak of summer. Stick on copper tape in a bass guitar should last a long time but it has always seemed to me that metal loaded conductive paint would be easier to deal with. I've looked at SuperShield and it appears to be an excellent product. The trouble is that I'd rather have a bulk liquid than a spray can but the smallest liquid containers they sell are about a liter and $175. And that is for the nickel product, the silver and silver/copper products get quite expensive. An even bigger problem is that my shielding needs are mild enough that I can just ignore them since I only play at one venue, a church, and I have "work arounds" to deal with any issues there. So Far.... I'm about to do some work on a couple of my basses anyway so it would be a good time to get around to shielding them too. Maybe I can buy a $36 spray can of SuperShield and bleed off the propellant so I can recover the liquid? The price break for the 900ml can of liquid isn't large enough to make a group buy worth the effort unfortunately, even if there were a group that was interested.

 

[joelb79]

I have personally had copper shielding tape come loose inside basses I've built, causing erratic shorting problems. More than once, which is why I stopped using it. The problem was always the same thing: the adhesive wasn't strong enough to stick to a painted wood surface that any significant roughness to it. The particular problem was the routed side walls of the cavities. They were routed smooth, and had several coats of base finish on them. But any little bumps or dust or rough grain would prevent the adhesive from sticking down fully.

I report same problem.. specifically my dealings with Warmoth bodies. Never had paint peel off.