I also have had tape come loose. I've also had it not come loose. The main problem with loose tape seemed to be when I sprayed the copper myself with sticky glue. Sometimes I guess the coating was to thick or too thin in spots. Pre-coated copper (for making stained glass windows) seems fine, but drying out is always a fear.
Also let me note that I'm paranoid about the tape with conductive glue drying out and losing contact. So I always solder connections and don't use conductive glue tape.
Sorry, I had to laugh at that. Your paranoia about the possibility of conductive adhesive drying out actually
caused your problems with copper tape coming loose.
Using solder and using conductive adhesive are not two mutually exclusive things. By using copper tape with conductive adhesive
and soldering the seams, you get the best of both worlds.
But nothing is perfect and paint has problems too. Good paint is expensive and sometimes for unknown reasons it just doesn't develop the conductivity it should. Not sure why. Even cavities coming from Fender will do this sometimes. So like anything it's all about choices .
Aluminum does a good shield job but is harder to ground. ALL pieces of shielding MUST be grounded. "Ground" would be the control plate on a jazz bass. If all the aluminum pieces go up over the lip and the control plate mashes them, that will work fine. For a pickguard (also where aluminum is common) you have to run the aluminum (or copper) over to a screw and run foil from the control cavity to that screw to make contact. The more contacts the better. Connections on aluminum have to be screws and washers since soldering won't work easily.
Part of the problem with paint is that instead of one large conductor, it relies on millions of microscopic conductors, and there's no way to guarantee even distribution. The other part of the problem is that there is way to even measure it. In the end, it invariably reads more resistance than copper, which is not a good thing. Paint has its uses, but it's a compromise.
That said, personally, I'd prefer to use paint than use aluminum. Copper is a better conductor, and it's easier to work with. IMO there are too many disadvantages to using aluminum. I can't think of a single reason why someone would prefer to use aluminum than copper. (If someone says "cost", I would direct their attention to ebay, where you could get more copper tape than you'd know what to do with for under $20.)
Finally shielding is never perfect and to be best you have to also shield the pickup cavities AND the wire channels leading to them! Of course the tops of the pickups are always open so it's never totally 100%. The only time I've ever seen shielding change tone is when shielding was installed INSIDE the pickup covers. I've never seen shielding a pickup rout and wire channel do anything to tone.
+1. To achieve perfection would take hundreds of thousands of dollars or more, plus a laboratory environment, so we have to find the best middle ground between perfect and practical and cost-effective.
Like you, I advocate shielding the wire channels. Some people prefer to use shielded wires for the pickups, and that's fine (though I wouldn't do it if it involves me changing the pickup wires myself). But I think it's silly to go to the trouble of shielding the interior of a bass and ignore that part of it. For people who choose not to, there might then be a discussion of how much shielding actually helps, but that's kinda beside the point. The decision to shield a bass is predicated on the idea that it
is helpful.
It's like... You don't make the decision to put airbags in a car because they they are beneficial, and then only put one in because you don't know
how beneficial.
I also shield the pickup routes. I know the faces are open, and therefore there's no way to get the Faraday Cage effect at that point, but I still do it. My personal theory is this -- if a shielded pickup route is not grounded, it would act like a radar dish, reflecting and directing RF energy right into the pickup. But because it is grounded, it acts more like a baseball backstop, absorbing most of the energy so that it doesn't affect the signal.
SUPER JOB! I've found that a pencil eraser does a good job of molding the copper foil to the cavity along with the sticks etc, (I like to use the rounded wrong end of plastic-handled cheap artist's brushes). When the copper is nicely molded to the cavity like yours I find that even were the glue to dry out, the form-fitting of the copper keeps it in place so it won't short anything. I usually just roll up copper tubes for wire channels tacking them to cavity foils on both ends. And that makes a nice solid connection between the control cavity and pickup cavity shielding.
Thanks! I actually use dental tools for the inside corners. I picked up a set when I was in the Marines because they were very helpful for cleaning guns.
I wish you would let go of the idea that the adhesive will dry out on copper tape. The only time the adhesive would fail is when the tape was not properly set in the first place. (Unless the adhesive is bad to begin with, but that should be apparent when it is being applied.) The surface has to be clean, with no dust, dirt, or loose grains of wood, and then the tape must be firmly placed so that all of the adhesive is engaged. That means pressing down on every square millimeter. I use the back of my fingernails for that. I prefer that to using an eraser, just because I can better feel how much pressure I'm applying.
But as I mentioned earlier, I don't just rely on that. I use multiple layers and solder as well. which holds and reinforces the shape of the copper to the shape of the cavity. And then it's anchored in place by the controls, the soldered wire channels, the jack, the pickup screws and foam, and the pickguard/control panel screws.
My shielding isn't going anywhere, ever.
