I want to buy a new black guard for my P bass, but I have a new tort one, and the new ones are not shielded. Whenever the tort guard is on, I pick up hum in certain places I play. No problem with any of my stock pickguards, which are shielded. Question is how do I go about shielding these pickguards? I know you can buy copper tape - I've heard it is difficult to work with, and the sharp edges can cause severe allergic reactions if they cut you. I was given a little bit of 1/2" copper tape and put some of it on my tort guard, but it still hums a bit - I didn't do it as completely as Fender does for the stock guards in the factory, so that's likely why. I also have some wider tape that is used for sealing duct work, I guess it is aluminium, not sure what it is made of. I have quite a bit of it - would it work? Why the heck doesn't Fender shield their after market pickguards if they shield the stock ones?