How-to guide - Shielding a '72 Telecaster Custom
This article focuses on a stunning MIM reissue model, thanks to a customers guitar that came in for a setup and some reliability upgrades. I was asked to apply copper foil shielding throughout the cavities, as well as supply and fit one of my pre-wired Tele custom wiring looms so I figured it was a great opportunity to share my processes in the hope it helps some of you readers out with your own projects too!
Let's kick things off with what parts you'll need -
Copper Foil Shielding
There is of course a number of ways you may choose to shield the cavities of your guitar, from conductive paint to self adhesive aluminium and copper foil. I must admit, I personally favour copper foil shielding having used in countless times with great results. If you're looking to buy some, I would recommend ensuring you opt for conductive adhesive copper foil as this is an awful lot easier to work with. A simple overlap of each piece will be all you need to do to ensure continuity throughout, rather than needing to ensure you flow solder between each and every piece. I will be using the foil shielding that I stock, which is available to order here in 8"x12" sheets. It cuts easily with sharp scissors, or a blade and is incredibly easy to work with. For reference, for this full cavity and pickguard application I needed around 2 to 3 8"x12" sheets, so if you want to ensure you don't run out, best to order x3 quantities of 8"x12" sheets and you'll have a comfortable amount to work with.
If you need to purchase some Copper Foil Shielding for this job, perhaps consider doing so through my online store HERE
I personally love working with Gavitt wire. Yes, it is the 'vintage' style, period correct option, but I don't specifically choose to use it for that reason. I primarily use it because it is very easy to work with, it handles great both to expose the central core wire and to 'manipulate' within the cavity to achieve nice and neat installs. It is also very consistently made, accurate to it's specified gauge (AWG) and also comes supplied pre-tinned which helps during soldering. In particularly for wiring a Telecaster Custom, with it's multiple, long wire runs between the switch and pots section, using one colour might end up being tricky to figure out which wire is which. So Gavitt produce their cloth wire in different colours! I stock Gavitt wire in the range of colours available, so should you need to purchase some lengths of wire to carry out this wiring job, perhaps consider doing so through my online store HERE
Most retailers, including myself, tend to offer Gavitt wire supplied in 2ft lengths. Realistically if you are doing this with each colour, 2ft length of off-white, black, red, yellow will do the trick
You may also notice on my documented wiring work here, I apply little cuts of heat shrink tubing to the ends of each piece of wire. This isn't specifically necessary for your own install. I merely do this as I find it helps 'seal' the cut ends of the cloth to further help prevent it from fraying. At the end of the day I am selling pre-wired kits and intend for them to look as neat as possible, and foresee any handling mishaps too, so any extra little details like that are simply done for professionalism. You can certainly attach you wires without these little heat shrink additions, but if you wish to do so, feel free to follow my lead :) It is also useful for keeping the longer wire runs neatly tied together, you can do this with tape etc if you wish, or you can do so via heat shrink tubing like I will be doing throughout this wire up. Heat shrink is available HERE
I'll try to keep this to the bare essentials needed for carrying out this task, but when it comes to specialist tools, the more the merrier I say!
Minimum 40W soldering iron
I say a minimum of 40W as most solder wire you can buy these days is lead-free, and lead free does require a hotter iron/working temp due to it's higher melting point. A 40w Iron should achieve a working temp of somewhere around 400 degrees C, which is great for lead free soldering and in particular making your ground connections (pot casings etc).
There are varying specs, and quality of solder wire available. If it helps, I personally use Rapid/R-Tech lead-free 22SWG 0.7mm. It has a flux core so you don't need to use flux additionally, but overall I find this to be a good lead-free solder wire to use for guitar/bass wiring work. Techs/luthiers etc tend to have their own preferences though, but this is what I use everyday so hope this helps narrow down your search. Ideally use this in conjunction with some form of fume extraction, or in a well ventilated area. Although lead-free is of course, as the name suggests, the fumes from the flux is still pretty nasty really, so best to think about how to do all of this safely.
You'll need some cutters to trim your wire length, if you have some guitar string cutters for example those might be useful here too for example.
1/2" or 13mm Socket/spanner
This will be used to tighten the CTS and Switchcraft / Pure Tone jack mounting nut when fitting the pots and jack to your control plate.
This will be used to remove/re-fit the pickguard and pickups
Small flat head screwdriver or Allen key set
This will be used if you have grub screw secured control knobs for example. Many of these traditional control knobs have a small flat head grub screw to secure the knob to the pot shaft. Some however have allen key grub screws so inspect what control knobs you have and go from there. What size you need will depend on the specific control knobs used.
These are of course useful for a number of tasks, but primarily here it's useful to test the continuity and effectiveness of your copper foil shielding that will be applied.
Scissors and/or blade
These will be for cutting/trimming your copper foil shielding tape
Getting started with the shielding
Needless to say, Please take care of yourself and your bass when carrying out any wiring work. I / James' Home of Tone cannot be held responsible for any damage caused by dangerous or incorrect techniques used. But hopefully this guide helps prevent any of that. So let's dive in to the action!
Now first thing you'll need to do here is strip down the guitar so you can easily access the control cavities. For fully effective shielding of the cavities, I will be doing the full main cavity from the switch, through to the neck pickup route and down to the main pots section. As well as the bridge pickup cavity and underside of the pickguard, so I start by stripping the guitar right back. This also gives me good opportunity to inspect the factory wiring style and specs, which might be useful if you are re-wiring the guitar too.
So off with the strings, then I make a start on the many, many pickguard screws found on a Tele custom! Make use of a parts tub here, you'll thank me when all of the various fixings you remove are safely stored ready for re-installation later on.
Then I remove the control knobs. On this reissue they are secured to the pots via a flat head grub screw, so I grab my screwdriver and remove all four.
Now we can access the pot mounting nuts, as the originals are still CTS, I can use my 1/2" or 13mm Socket to loosen each of these.
Here's a quick look at the spec and condition of the original wiring style. Who ordered the spaghetti?!
Whilst I still have that socket to hand, I then loosen the jack socket. This has the traditional jack cup, meaning it is only held in place via the actual jack socket nut itself. So I loosen that which also removes the jack cup for me too.
Final step to release the loom from the pickguard is to loosen the 4 screws for the neck WRH, and loosen the pickup selector switch mounting nut.
Now, you may try and fight with the loom and shield the guitar without completely removing it, and I don't blame you for not wanting to add more soldering work if you don't have to. I do personally find it much easier to access everything with the guitar completely stripped, and on this ocassion will be re-wiring the guitar with all new wiring components anyway so it is a no brainer for me to fully strip it here. I'll leave it up to you, but bare in mind this guide will show it with everything removed.
So with that said, I need to locate a few connections to snip, to be able to easily remove the loom from the body. This is the neck pickup 'hot' and ground, the bridge pickup hot and ground, and the main bridge ground wire.
The neck pickup hot and ground will usually be located on the neck volume pot, with the 'hot' heading into the input lug, and the ground being on the pot casing. Then the bridge pickup wires being the same but on the bridge volume pot. As suspected, they were indeed! So I simply snipped those off right at the connection to leave me with plenty of wire left to work with. You could of course also de-solder this if you wish to.
With each of those wired connections snipped, I can lift out the loom in one piece, the neck pickup separately, and then also remove the bridge assembly. On the Telecaster Custom, as you likely already know, the bridge pickup is mounted/suspended from the bridge plate. So locate the 3 or 4 bridge plate mounting screws and remove those, which will in turn then allow you to lift all of that off in one assembly. Leaving you with a guitar body that should look a little like the example above (hopefully cleaner though!)
As you can see, the cavities were in a messy state on this one. An older guitar, paired with lots of left over dried up polishing compound by the looks of it! I won't be able to apply any self adhesive sheets to that and expect any of it to stick, so a thorough clean is needed next.
It was much of the same story with the pickguard, lots of dust and old dried polishing compound. So I need to clean that up. This guard also had a small aluminium foil shielding section taped to where the pots sit, this really wasn't doing much, especially considering the pots had ground continuity between them anyway due to there being a dedicated soldered ground wire between each. But hey ho, it's there and I need to remove it before applying my new copper foil shielding. So I peel that off and clean up the pickguard too.
With the cavity cleaned up, the pickguard stripped and clean. It's time to get stuck in with the foil shielding! So the guitars back on the bench and I reach for the copper foil sheets.
I tend to choose an area to start at, and work my way across the body/cavity. Usually covering the bottom of the cavity first, then all of the sidewalls. So what better place that the top, at the switch cavity. A useful technique to rough out the cavity shapes is to place your foil over the cavity, hold in place and gently press around the edges of the cavity with your finger. This will leave a indentation in the foil and give you a line to follow when trimming.
Also, it's good to work in smaller areas, rather than trying to do huge spans of cavity. The foil we're using is fully conductive, so simply overlapping each piece will provide continuity through to the next. Smaller pieces are easier to work with and handle, so make your life easier I say!
First piece in place, so onto the wire channel base with the same method. Place some foil over the area, use your finger to create an impression guide for cutting.
Working my way along into the neck humbucker route, ensuring I have overlapped with the previous piece of foil.
Down the long wire channel to the pots section. This is a satisfying one to shape out on these.
With the base of all the cavity covered, I can now make a start on the sidewalls. I must admit, this is the trickier part as some areas of the cavity are quite deep and tricky to access. Along with the curved corners too, it's one you'll need some patience to complete I'm afraid. Work in sections, smaller the better, and work your way around. I find a small ruler handy here, measuring the sidewall depth and using a straight edge to mark and cut strips of foil shielding to apply.
You may have spotted the sections overlapping the sidewall and onto the body top. This is done so that when the pickguard is mounted up, it is making solid contact with the shielding foil on the pickguard too ensuring continuity and effective shielding throughout. This is perhaps a bit of an extreme example, a small overlap is fine too. But seeing as we have loads of real estate underneath the big 'ol Tele Custom pickguard, I went with a nice clear example for you.
Below is an example of the smaller sections I cut to work my way around the sidewalls in the pots cavity. With the various curves within this section, it is fiddly, so making smaller pieces is much easier to apply and handle as you work your way around it.
Hopefully as you're progressing along, you should see something similar to this throughout. Full coverage of the cavities and each piece overlapping.
With that all applied, it's time to get the soldering iron out. The Telecaster Custom has two separate cavities, the main one and the bridge pickup route. For effective shielding we need to ensure those have continuity between them, and to do that will depend on what spec of bridge pickup you have. On this particular guitar, the bridge pickup didn't have a baseplate fitted. Some telecaster bridge pickups will have a metal baseplate fitted to the underside of the pickup. Below is a photo example of what this would look like -
Pickups with a baseplate are quite useful when it comes to grounding a bridge on a Tele, because when you mount the pickup to the bridge via the three metal screws, they are in effect making contact with the bridge plate and the ground signal of the pickup. So on these occasions, simply mounting the pickup and fitting the bridge back in will achieve ground continuity from your bridge and bridge cavity too. But what if your pickup doesn't have a baseplate, like this example below perhaps?
For this construction/spec of bridge pickup, it won't simply provide us with ground continuity solely by mounting it to the bridge. So here, I need to fit a separate ground wire between these sections. The model I'm working on was in this camp, so let's show how I did it.
To ensure the pickup would still comfortably fit in the tight tele pickup cavity, I try to position this ground wire as neat and minimal as possible. So I've tucked it right by the existing wire channel hole, and flowed some solder to secure it.
I then feed that wire through to the pots cavity and do the same again, keeping it neat and simply flowing some solder to secure it to the shielding tape.
Now onto the pickguard and our final steps of tape application. For a Tele Custom you don't have to completely cover the entire pickguard, just the key areas that will be where the cavities sit against it. So that's the pots area, wire channels, pickup route and switch area.
Trim the shape out with a blade, and cut out the pot and switch holes ready for mounting of the components shortly.
Voila! We've finished applying all of the tape, so now onto the important bit. Testing for continuity! So grab your multi meter, and set it to the continuity setting.
Here we'll need to check that each piece of overlapped foil shielding tape is effective and has continuity. I find it good habit to ensure I check every single piece I've applied, that way you know your shielding is effective and doing it's job correctly when everything is back in and wired up. Kinda pointless otherwise eh!
Place one probe on one section, and the other on each connecting piece and listen for that reassuring 'beep' from your meter.
And repeat the process for the body too. Checking each piece throughout.
For my final continuity check, I re-mount the pickup to the bridge and fit that assembly to the guitar. That way I can check with the multi-meter that my bridge will have ground continuity too.
One thing I will quickly mention too, is ensure your bridge plate is flush with the body. One common complaint with Teles is that the bridge position can seem quite noisy or microphonic. I have seen two examples of what can cause this, one being the bridge plate not sitting completely flush with the body. The other is if the pickup has a copper baseplate like the example photos I shared earlier, which has come slightly apart from the pickup itself. So whilst mounting these back to the guitar, just check they're nice and flush mounted so you're not scratching your head later on wondering why it's seemingly noisy!
And there we have it, copper foil shielding complete and ready for the wiring to go back in! I hope this helps with your own foil application, but please don't skip the testing part. That is super important, otherwise any possible continuity issues will mean your shielding isn't effective, and might even cause more issues that it helps. So take your time, work in sections, use quality conductive self adhesive foil sheets if possible and test it all at the end!
Now, we'll be re-wiring this Tele custom so if you want to stick around and learn how to do that too, I'll be publishing an article very soon on the subject so stay tuned!
Have you made good use of some of the free resources here? Perhaps you might consider kindly supporting this free resource for guitarists via 'Buy me a coffee'! Thank you so much!