With, (I think), five projects on the go at the moment – I’m spoiled for choice. January’s sometimes not so great, however, for project work. The weather’s not conducive to hours in the workshop and, more often than not, I’m usually sat around waiting for parts to arrive. This year, with the effects of Covid and Brexit – things seem especially “stuck”.
But at least I can press on a bit, with my Gold leafed Hardtail Stratocaster. The body was polished up towards the end of last year, and I already have a few extra components put aside, specifically for that build. The polish job has resulted in a really nice, glossy finish. The only thing that bugs me about the way the body has turned out, is that there’s an area just down towards the lower strap button where the finish has slightly, but noticeably, darkened when viewed from certain angles. It’s hard to photograph – but there’s a slight, apparent cloudiness to the “fire” of the imitation gold leaf which isn’t quite consistent with the rest of the finish. Looking at it – I suspect that, because the area coincides with where the arm cutaway and curve of the lower bout coincide, then the area might have been slightly more exposed during the lengthy sanding and polishing process. I suspect I may have actually sanded extremely close to the metal leaf at this point – perhaps allowing the leaf to oxidise slightly more. There’s a slight change in hue noticeable too. Slightly more red – which shows itself against the general yellow/green colouration. Maybe that’s the gold undercoat or primer showing through a little more? Another possible cause might be some additional faulting – done at the time of gilding. Unfortunately, that was so long ago now, that I’ve completely forgotten. Although it really should help to keep notes.
Anyway – it seems to come and go under different lighting conditions, as well as when the body is moved around. I’ll see if I can live with it as the fit-out continues. If it continues to bug me – I’ll just have to put a sticker over it, or something. I’m not too worried about it. It’s one of those things that, when you first see it, you can’t help but see it. Eventually, in time, the eye tends to settle on other things.
I’ve developed a set procedure for shielding and grounding most of my electric builds. I line all of the inside cavities with conductive copper foil, and link them together to provide a single, contiguous ground. I also use a central “star” grounding system – where all of the pickup circuit grounds are brought together, at one location. It’s always seemed logical to me, to link this point directly to the shielding, since both “run to ground”. This way – most of the ground side of the circuit is completely self-contained within the body of the guitar. The pickups and control elements can be assembled on the scratchplate separately, dropped in, and then “hooked up” using just a single connection to the “star” ground point. This makes for an effective way to swap out different pickups or controls, without too much fiddling about. In theory – it means I can swap out completely different pickup setups, with the minimum of soldering and fuss.
On Stratocasters, I prefer to locate the central ground point on the side of the main control cavity – just adjacent to where the bridge pickup rout cuts in. This keeps the lug away from the nearby volume pot – but also keeps the length of the required linking ground wire reasonably short. One further advantage of this location, is that I can use the length of the control cavity to accommodate a screwdriver, and keep the angle of the short securing screw as shallow as possible. I punch a pilot hole with a sharp awl, and then drive a short screw into the opening, with a metal lug in place. The lug will eventually provide connections to the scratchplate, and jack socket grounds.
On a hardtail Stratocaster, the bridge unit is a simple, surface mounted, affair – with just three securing screws. The Fender bridge unit, (Fender parts number 006-0068-000) comes complete with six, classic style string saddles – but these have to be removed, so that the bridge plate can be screwed into place. It’s similar to the simple Fender Precision Bass bridge – with just three anchor screws instead of six, as seen with the usual Stratocaster tremolo bridge units.
The pilot location holes for the bridge are already marked on the body. All I need to do is drill them out to the required depth. I do this using a Dremel tool on a plunge base. That way, I can keep the holes straight and true, and also stop off the plunge to the correct depth. With the holes drilled out, I can then fit the bridge for the first time using the supplied screws. A little wax as a lubricant helps the screws tap home, without too much torque needed to overcome friction.
The bridge unit sits isolated on the face of the guitar body, and I need to find a way to ground it – otherwise it might end up providing intermittent hum and interference. I could just run a short wire under the adjacent scratchplate, and route it into the bridge pickup rout – but I can do something a bit more elegant, and conceal everything from view. I cut a small rectangle of conductive copper foil, and stick it to the body where it will remain completely covered from view. This should help provide a good contact between the bridge and the body.
I can then drill a small hole – using a countersink burr – just in front of the top “B” and “E” string holes. Using a countersink provides me with a cone shaped indentation, and that is perfect to help initially support a long “aircraft” drill bit, at a shallow angle. This enables me to drill a through conduit to the main control cavity, without too much fear that the bit might accidentally skip out, and damage the polished body.
In order to link all of the grounds to the central point, it’s necessary to install connecting wires to incorporate isolated and “outlying” elements. In this case – the main control cavity is already physically linked to the pickup routs. However the jack socket rout, and the hardtail bridge are physically separate. Connecting wires need to be installed, and it makes sense to complete this before copper-lining all of the cavities. That way the job will be more secure, and the whole thing will be finished nicely.
The first thing to do, is to lay a main connecting wire between the control and jack cavities. I use a length of tinned copper wire – trimmed and bent to shape. At the “star” ground point – I push the end of the wire into the screw hole, and then use the screw and lug to hold it in place, temporarily. If there’s a need to secure other points, and to hold things in place – I use short pieces of copper foil. The wire is trimmed and shaped so that it runs around the lower corners of the control and jack cavities, and through the small inter-connecting conduit hole, which has already been pre-drilled.
A separate piece of black, cloth-covered, stranded wire is then fed through the newly-drilled, bridge conduit hole. The length is cut, with a fair bit of surplus left at the bridge end. At the control rout end, the covering is pushed back, and the wires are twisted around the main connecting wire a few times. This connection is then secured with a dab of solder. Any slack can then be taken up at the bridge end, and the main connecting wire can be relocated, if it’s been moved out of position.
At the bridge side of things – the cloth-covered ground wire is trimmed to length, and the cover is stripped back to where it emerges on the face of the body. The wire length is trimmed, so that it’s long enough to be fully inserted into the nearby bridge screw hole and then lay flat – over the copper foil grounding patch. After checking the continuity between the two wires – I use a couple of small patches of copper foil to secure the bridge wire in place, and to build up a slight bump above the wire.
Once the bridge is screwed down into place – the screw will physically connect with the ground wire, and the downward pressure of the bridge plate should provide a further, effective, contact point where the wire runs across the body.
The bridge is screwed tightly down into place again, and the bridge saddles can now be re-installed. It might be an option to keep them off for now, but as long as they’re screwed back, and the springs are under a fair bit of tension – they don’t tend to flap about too much. Plus – with five projects on the go – parts can sometimes get confused. Sometimes it can be a better idea to “store” them in place. With the bridge plate in place – connectivity can again be tested between the bridge and the “star” ground.
Copper foil is then used to line all of the main cavities. Where it runs over the concealed ground wires, it is pushed into place and burnished down well. Sometimes a few layers have to be applied over the actual wires, since the process of burnishing can rip and tear the foil. In exceptionally difficult cases – such as in corners – a little solder can be flowed to provide a conductive “plug”, which bridges any physical gaps. Any solder repairs are covered over with copper foil patches, and the surface is burnished all over to provide the best adhesion between separate pieces of foil, and between the foil and the wood of the body. At the edges of the cutouts, the foil is lapped over onto the face of the body by about a millimeter. I know it’s all hidden by the scratchplate – but I like to take a pride in even this, small, detail.
I always use a slightly heavier grade of copper foil, and also choose one with a good, conductive adhesive. This means I can keep the lining as thin as possible, and also avoid having to lay solder connections between each separate piece. Consequently, now that I’ve developed a reasonable technique, I can usually line all of the various chambers and routs with just one and a half, A4 sheets of foil.
At the jack plug rout – the cavity is shielded with foil, but the overlap onto the face of the body is extended slightly at each end, to help ground the actual jack plate. The overlaps are shaped so that nothing shows once the plate is in place, but they run to include the screw locations for the plate. These are marked out and drilled to size. Their location is decided by test-fitting the jack plate, with a jack inserted into the socket. I’ve found that the jack retaining spring can sometimes move backwards slightly under operation, and it can sometimes foul the back of the cavity if the plate is fitted too far back. This sometimes leaves the jack socket feeling stiff, and you don’t get that reassuring click as the jack is pushed in.
Additionally – I don’t know if some jack plates come with more rounded, internal curves – (this is a Fender plate, parts number 099-1940-100) – but some seem to fit better than others. I’m beginning to wonder if it might be worth slightly rounding the edge of the jack rout, on future Strat projects. Anyway – I find the best location for the plate, mark the screw locations and then drill them out with the correct sized drill bit. Before tapping the screws for the first time, I shape and repair the copper foil overlaps at the ends – so that they cover the holes, and provide two slightly raised “bumps”. Once again – the screws should have a bit of physical contact with the conductive foil, and the downward pressure of the plate will add additional points of contact around the rim.
However, before the plate is screwed down – I add an additional layer of insulation at the very back of the rout, with a few thicknesses of electrical insulation tape. This is just in case the jack spring does extend that little bit too far under operation. The insulation should prevent an accidental short between the “hot” tip of the jack, and the contiguous ground. With the insulating tape burnished down, the jack plate is firmly screwed down into position. Continuity is then checked with a multimeter – between the jack plate and the bridge plate, and from all grounded surfaces and elements to the central “star” ground.
Once ground continuity is confirmed throughout, I might as well take the opportunity to install a new pair of nickel, Fender “Pure Vintage” strap buttons, (Fender parts number 099-4915-000). Holes are marked and drilled out using the correct-sized bit, and then lightly countersunk to clean up the edges, and to try and prevent lacquer from chipping off over time. The buttons are screwed into place using the screws provided, and with the addition of a white felt washer, (Fender parts number 099-4930-000), at each location.
The body is now showing a few signs of being handled, and has lost some of that, “as new”, polished shine. Now’s a good time to polish out any handling marks on the metal components, and to renew the polish generally.