Wednesday, 12 November 2014

Black Ash Telecaster: Shielding for Slugs

Sitting at home today, willing the postman to deliver unto me some shielding tape so that my raft of current builds could continue, I remembered something that I had read in one of the guitar building forums around the place. It was postulated that copper tape sold as "slug barrier" tape could be used just as efffectively to shield a guitar as "sold for purpose" copper shielding. That couldn't be true could it??

Well, with this in mind, and with no postman in sight, I decided to head to my local Masters (big-chain hardware) and see if there was any truth to it - if slug barrier tape could indeed be the answer to my short-term shielding woes. Luckily I managed to find some - 10 metres for 8 bucks. It seemed like a bargain, but would it serve for shielding?

Well, I got the stuff home and proceeded to run a few quick tests to see how it performed. What I really needed to know was:

1. Do overlapping pieces form a continuous conductive surface?
Well, yes they do! I used three lengths stuck down to a piece of pine with a 0.5cm overlap. The surface did indeed register conductivity on my multimeter with a resistance of 0 Ohms. Great so far!

2. Can I solder directly to the tape and does the solder joint conduct?
Well, yes absolutely! The solder went straight on to the tape without any problems at all. A little flux was all that was needed (I use flux-cored solder) and the solder stuck fast with a nice clean joint.

In summary, the barrier tape performed identically to the tape I've been buying from ebay and other suppliers as "double sided conductive" shielding tape. Amazing!

With my 10 metres of tape in hand I dove straight into shielding the pickup and control cavities of the Black Ash Telecaster. The tape went on without any problems at all. Ground wires were easily soldered to the cavity walls to join all the cavities electrically, and then the bridge cavity was joined to the bridge using an underside bare wire.

To wire this beasty I'm using 250K Bournes mini-pots, an Orange Drop capacitor and a 4-way Oak-Grigsby switch. First time I've tried a 4-way switch on a Telecaster, but that's not surprising given it's only the second one I've ever built ;). I'm hoping it will extend the range of tones she will be able to produce - especially the new "series" setting. The circuit for the 4-way wiring scheme can be found on DIYGuitarMods and is shown below.

As it stands, the wiring of the control plate is all but completed (you can see it in the photo above) following the schema in the diagram. All that remains is for me to attach the pickups to the switch and to connect the output jack to its wires. This will be tomorrow's job, in addition to looking at the neck angle. With the bridge now in place it looks suspiciously like a shim is going to be needed - bummer.