Brian's Guitar from Conception to Birth or How to Build a Guitar in 62 Easy Steps!
Electronics & Hardware
56 Shield the Cavity
Guitar electronics are very sensitive. Think about it, that vibrating guitar string is all that’s powering your sound. To keep out any unwanted noise or radio signals from getting into the mix, you must shield the control cavity. You can do this with a special type of paint or with copper foil. Either method works; we chose the foil. Lay the guitar face down on a soft, clean towel. Pick out any glue ooze from the inside of the cavity so you have nice clean corners. The copper foil has an adhesive back which makes things a little easier. Start with the bottom of the cavity. Cut off a small strip a little over the size you need. You want the foil to fold up the sides a little. This will provide a continuous, connected barrier. Peel off the backing and stick it in. To make sure the foil is fully seated and well stuck, burnish it by rubbing it with a small piece of wood or MDF getting into all the tight areas. Cut out the next strip and overlap the first by a few millimeters. Once the bottom is done, start on the sides. Make sure you foil over the top lip where your cavity cover will nest. If there are any areas where the adhesive doesn’t take, help it out with a drop of CA glue. This is a tedious job for big fingers in a small space; just take your time. When you’re done, cut out your knob and switch holes and your cavity cover mounting holes with an Exacto knife.
The cavity cover is much easier. Cut a piece of foil a little oversize, burnish it on, flip the cover over, and trim off the excess. The edges of the cover will rest on the foiled lip providing a continuous, connected barrier.