Today we have something new for you, a video! I’ve made an easy, quick 45 minute video on how to install copper shielding on your bass. Copper shielding essentially does what you would think it does, it shields your electronics from outside interference and helps reduce hum. I highly recommend watching the video, however, below is an accompanying article if you prefer to read, print out, or translate. You can always email me firstname.lastname@example.org if you need assistance or comment on our YouTube video or Vimeo video.
Tools You Will Need:
- Two packages of copper foil tape with adhesive backing
- 80 grit sand paper
- Sanding stick or similar tool to work out foil wrinkles
- Naphtha solution
- Continuity tester to check conductivity
Step 1: Set Up You Bass & Take Out Electronics
First things first, pull out the electronics from the control cavity and take off all the knobs. You’ll need it cleared out so you can get to work. It’s best to have a cloth to place your electronics on since you’re probably going to be moving them around a bit during installation and you don’t want them to scratch your bass.
Step 2: Prepare & Sand The Cavity
Next you want to prepare the cavity for the copper foil. Most likely the wood and finish were left rough inside the cavity. This makes applying the foil difficult, so what you want to do is smooth everything out with your sandpaper. It doesn’t have to be perfectly smooth, you just want to clean everything up and remove that gloss to help promote adhesion.
Tip! When it comes time to sand the bottom of the cavity you may find it easier to use a block sander.
Once you’ve adequately sanded it you need to clean all that dust out of the cavity and wipe everything down with Naphtha solution. This will remove any waxy oil that might left inside.
Give it a second to dry and you’ve got a nice clean smooth surface to stick your foil to.
Step 3: Shielding The Perimeter
Perhaps you’ve seen special paint used to shield control cavities. In my opinion, the paint just isn’t as substantial, so instead of trying to paint on layer after layer we use the tried and true 1″ copper foil. The corner where the bottom of the cavity meets the sidewall is often the most time consuming and difficult location to place your foil.
After you’ve cut your first piece of foil bend it into an “L” shape before placing it. This helps you really get into the corner. Now use your tool – a sanding stick without any sandpaper is ideal – to evenly push it down and work out any wrinkles. Start slow, take your time, and don’t try to do too long of a piece at one time.
Don’t worry about your exact placement of the foil because there will be some overlap of the pieces. And while you want to avoid big wrinkles when placing the foil, little ones are easy to burnish out with your tool. Work your way one piece at a time around the bottom perimeter of the cavity.
You’ll notice that it takes quite a few pieces and you might be wondering if you should be concerned about conductivity. Originally repair men used to solder pieces of copper foil together, so there is still a little confusion regarding this. Today’s copper foil shielding uses an adhesive that creates conductivity between the pieces, so there is no need to solder.
Step 4: Shielding The Bottom Of The Cavity
After you’ve completed the perimeter, things get easier. To shield the bottom of the cavity cut your pieces of foil with scissors to fit the contours. It’s much easier to work with the foil by cutting your piece to size first and then peeling away the adhesive strip.
Work your way from one side of the bottom to the other with each strip overlapping.
Step 5: Shielding The Walls
Like the bottom, finishing the sidewalls are relatively easy because you do not have to deal with any corners. Just work your way around the walls one piece at a time, placing down the foil, working out any wrinkles, and making sure it has a good connection to its neighboring pieces of foil.
Step 6: Shielding The Recess At The Top
After the side walls are shielded you want to start with the recess at the top of the cavity. This is where the foil from the back of the cover comes into contact with the foil you are installing in the cavity. You want to make sure that you have enough to make contact, but not so much that it will be visible after the cover is in place.
For these pieces, it’s easiest to start from the top and then fold them down. Just try to cut them fairly well to fit since it will be the finished edge of the installation.
Don’t try to take on too much contour at one time. Sometimes it helps when doing a turn to place the foil on the lip then cut a small slit at the bottom so it is easier to lay flat and without big wrinkles.
Step 7: Shielding The Control Cabinet Cover
Now the whole control cavity has been copper shielded. All you have left to do is shield the control cabinet cover, which should be quick and easy. Just make sure to clean it off a bit, and then adhere overlapping pieces of foil. When it is correctly in place, it will make contact with everything we’ve foiled in the cavity.
Again, work your way one piece at a time around the recess making sure each piece overlaps the other.
Step 8: Testing Continuity
Once the cavity is shielded you don’t have to worry about attaching a wire to the copper foil to join it to the ground of the guitar because when you mount these components, which are all grounded, it is going to be on the same electrical potential anyway.
All you need to do now is test your shielding work with a continuity tester. Set it so it will beep when you put the two probes together. Now, check various points of the cavity to make sure that everything is connected.
After your bass is completely reassembled, do one last final test with the continuity tester by checking the strings against every other component to make sure that everything is properly joined together.