The tremolo plate is the first piece of hardware to fit onto the newly polished body. The tremolo is a pretty simple device, but one which will need setting up properly, at a later date. For now – a good fit needs to be established so that it can act as an anchor and, together with the bridge in place, help with checking the neck alignment – so that the neck bolts can be set, and the neck attached.
First I mask off the surrounding area. I’ve done a bit of research and one of the pieces of advice I see regularly, is to drill through masking tape. Apparently it’s supposed to help keep the paint around the hole in place. It also helps, in this case, to check that the plate sits centrally. There’s a small lock button which needs to operate at the front of the plate, and the tremolo spring needs to be clear of the sides so that the plate can pivot properly.
The screws are slightly shanked at the top – about 1/3rd of the overall depth – so they’ll ideally need drilling out to three different diameters. The deepest, narrowest, pilot hole for the business end of the screw. A slightly wider hole further towards the surface, for the shank of the screw and, finally, a lightly countersunk area at the surface, which should keep the paint finish clear from the screw threads entirely. The latter to help make sure the paint isn’t cracked by accident, later on. Since I’m most concerned about the paint finish – I decide, rightly or wrongly, to do the countersinking first, and then drill subsequently narrower and deeper holes at the centre of each countersink.
The countersink tools I have in the workshop are for wood, and I’ve been concerned for a while that they don’t seem to do a good enough job. They’re supposed to work with a hand drill – but they need a lot of pressure to stop them from jumping – creating kind of hexagon openings instead of circular ones. For that reason, I decide to follow some advice I find, and drill the countersinks with a sharp HSS drill. The advice says to drill backwards first – to cut into the paint without lifting it – before drilling out the hole in the conventional way. I start with the hole at top right of the tremolo assembly, and with everything crossed, I take a deep breath and cut the first hole through the masking tape at the location marked.
It seems to go OK, but when I lift the tape, a flake of paint comes away with the tape. Vital lesson. Don’t use masking tape that is too “grabby”. It looks like the new flaw in the paintwork will easily be hidden below the plate anyway, but I’m more concerned that the paint has flaked off the wood in the first place, and that other bits might possibly come away. Working counter clockwise, I try the next hole. Slightly better – but still a slight tear. The third one is the same. There must be a better way to do this.
I remember drilling through some ceramic tiles when I fitted out the kitchen a while back. I still have a few diamond tipped spade bits which made short work of the tiles. I wonder if it’ll work for hard paint finishes? The spade bits seem to cut whichever way they’re rotated. rather than removing the material up the drill helix – the diamond tips just seem to wear away at the surface. I decide to give it a try. I still drill the wrong way to mark the hole centre – but then press down enough to eat out a countersink big enough to clear the screw head. That, and a little bit to spare. (Like with the drill bits, I mark off the correct finishing depth on the spade bit with masking tape). The spade bit cuts a just about perfect circle, and as I continue to work round counter-clockwise, the countersink openings appear sharper at the edges. Looks like the diamond bits might be the way to go – for larger screw holes anyway. I might try the same thing for the scratchplate screws later.
Next, I drill out the holes for the screw shanks, and then the narrow centre holes, into which the screws will key. The screws should now hold securely – without touching the paint at all. However, I’ve seen some suggestions that a little dab of superglue around the countersink holes will help to bond the paint skin to the wood. Ensuring that any subsequent carelessness doesn’t result in flakes of finish being pulled off. I mask the hole areas off – just in case I dribble superglue all over my newly polished body – dab a little superglue around the edge of each hole, and then leave to dry.
Then it’s time to fit the plate and cut the screws in. I run a little wax along the thread of each screw and then drill them all, in turn, down to about 9/10 depth. Then, working across the plate, I tighten each screw down to just above biting point – working across to opposite sides and corners each time. The final turns are done until each screw just bites, but without too much downward pressure. I don’t want to tighten too hard, compress the wood of the body, and damage the paint finish underneath. Worse still – crack it. With the final screw tightened, my plate is fitted.
I remove it to check nothing has been damaged, (there are a couple of slight creases in the paint – but nothing alarming), so it’s refitted as before, and I’m ready to move on.
While I have the body on the bench – I take some 320 grit paper, and ream out the bridge thimble holes – where a film of paint has built up around, and narrowed the openings slightly at the surface. On test-fitting, the thimbles are still a little bit loose and, although the bridge will eventually rock about in the thimbles as part of the tremolo action – I don’t want even more movement with the thimbles as well. I take a few bits of adhesive copper foil, which I use for shielding the body cavities, and wind enough around each thimble to pad them out and create a snug fit. I’ll eventually have to run a little wire down one of the holes, (running out from underneath the scratchplate), in order to ground the bridge components. I make sure I can still get the thimbles out again, for when I need to, without digging into the paint. I can now test-fit the bridge, run a couple of strings up the neck to the fitted tuners, and check the neck alignment for fitting.