Normally, an extended twelve week blank in the diary would be an ideal opportunity to catch up on all sorts of activities. With a few projects on the go – and with most of the necessary components already sourced – I’d normally be looking at the prospect of three months isolation, with a great deal of anticipation. Although I still can’t see well enough to solder effectively, or focus on any minute details, I can’t really watch the opportunity disappear completely – so I decide to push on with the body repairs to the Classic 50’s Stratocaster. Most of the critical work will be in rubbing the finish down and polishing up. It’s a mostly tactile process, and I can get on with it using my fingers to gauge how smooth the finish is. The main difficulty will be in colour matching any repairs.
Most of the areas which need attention are areas where the polyester coat has fractured. In some places, there are indentations where the colour coat has been pushed into the wood below. In these cases, the loose polyester needs to be chipped away. There’s no point trying to stabilise shattered poly coat, and where the wood has been depressed and softened below – there may be a further need to repair and stabilise the substrate, and then reprime. I check over all of the problem areas, and work out which will need the most attention.
Some places will need a touch of colour to go over the repairs. I’ll then rely on a drop-filling technique using cyanoacrylate glue to fill and repair the gloss polyester coat. I can source Dakota Red nitrocellulose paint in spray cans – but I’ll only need a couple of spots here and there. An entire spray can sounds like overkill, and perhaps an unecessary expense. I’ve long dreamed of discovering a range of guitar spot colour repair kits – similar to the automotive alternatives available – but I suppose there’s just not the demand.
So – in considering alternatives, I’m left looking for a sort of solvent based, gel coat alternative, available in all sorts of funky colours. I hear on the grapevine that nail varnish might just be the thing I’m looking for. Now normally, the prospect of hawking a guitar body down to the local Superdrug, just to check out the make-up counters might be considered a touch risque. Especially here in the provinces. Truth be told – I rather enjoyed the process, and the sight of a bearded, middle-aged man at the nail bar raised only a few teenage eyebrows. I emerged with two likely colour candidates. Both seem incredibly close to Dakota Red, but studying the colour closely reveals just how it changes character under different illumination sources. Hopefully my choices will be close enough. Sometimes the body colour looks quite purple – other times quite scarlet. With all I need to repair the body now in hand – I set about dealing with each problem area in turn. I’ll not detail each in turn – but, rather, lay out the general approach I found most useful.
Deep indents, polyester coat fractures and chips which penetrate the colour coat
Where the clear coat has fractured, and where the damage extends through the colour coat to the wood below – it’s necessary to rake out all the loose material back to a stable substrate. I use the corner of a sharp Stanley knife blade to pick away at the finish, including any loose or compressed wood. For the deepest holes, a little wood filler can help reduce the eventual hole depth before colouring – but whatever forms the base of the scar needs to be stabilised and effectively primed. The easiest thing to do is to add a drop of shellac as a separating barrier. The scar can then be coloured with a little nail varnish, and then drop filled with Super Glue.
For drop filling – I use a pin or a needle to add small droplets of glue, a little at a time, gradually building up a raised plaque which fills the scar, and also flows over the edges of the poly coat. As long as each previous layer of fill material is fully dry – there appears to be little shrink back with the super glue, and once it has fully hardened, the simplest thing to do is to mask off the drop fill area, and then level with an emery board. (If you’re organised, you can get these at the same time you buy your nail varnish). Once the fill is almost level with the surrounding coat, I remove the masking tape and then roughly follow a procedure I saw originally outlined by Dan Erlewine at StewMac.
Starting with 240 grit, and then working up through the grades, small strips of grit paper are run over the area. The key is to hold each strip in place with light pressure from a finger, whilst drawing the paper out with the other hand. By changing the angle of attack, and by limiting each grade of grit to a few light passes, it’s possible to level off the fill whilst following the curves on the body. I also find it useful to gradually expand the sanded area as the grades get lighter and lighter. This helps feather-in the repair to the surrounding top coat. Once the edges of the repair have disappeared, and once the area feels totally smooth to the fingers – the grit should be fine enough to begin fine-polishing the area. At this point I usually switch to a set of Micro Mesh cloths, which gradually take me up to a super-fine 12000 grade. All it takes then, is a good polish with Swirl Remover, followed by a buff and polish with Carnauba Wax formula, and the fill is complete.
As it turns out, and as shown above, the colour match isn’t quite perfect – but it’s not bad. Whilst the colour match seemed OK before drop filling, the result after the cyanoacrylate has been polished up shows as a slightly darker freckle on the main body colour. Physically, however, the damaged areas have been stabilised and filled, and the fills have been well blended in with the body contours. If you know the repairs are there – you can easily spot them – but if the body is held up in the playing position the repiars are mostly lost in the reflections and highlights of the shiny body. Looks like the nail varnish solution isn’t perfect – but it’s close enough for Rock and Roll.
Small scratches and chips which do not penetrate the colour coat
In cases where the polyester clear coat is only slightly chipped – or where there’s a slight split – the resultant blemish appears to show up as a lighter colour. The best way I found to deal with these areas, (bearing in mind the previous, apparent discrepancies in colour matching), was to remove only just enough surface material so as to ensure the chip or split, together with the surrounding area, can be drop filled without having to add much extra colouring pigment. It’s important therefore not to expose the wood below, and to only remove clear polyester or top layer gel coat. The exposed, scratched, gel coat tends to show as a much lighter colour – but we’re not finished yet.
Once the area has been picked back, and all loose material removed, the area can be cleaned with naptha, and then stabilised with a drop of shellac. This seems to act like a varnish over a colour coat, and “wetting” the gel coat surface seems to return it to the original, desired colour. Although the shellac is a kind of straw colour – I’ve found that this doesn’t change the gel coat colour too much, and overall gives a slightly better colour match result than using too much extra nail varnish – although that remains an option for small spots and scratches if you accidentally expose the wood below.
Once the shellac is fully dry – the repair can be smoothed and polished after drop-filling in the manner summarised above.
Once all the repairs have been done, I give the whole body a gentle work over with swirl remover, and then a full buff and polish using a rotary buffing machine and a high quality Meguiar’s Carnauba wax formula which contains no silicone. The end result is satisfyingly shiny and, although I can see the areas of repair, I know they’ll be practically invisible to most people under most lighting conditions. As it is – all the repairs are either on the sides or back of the body – and the front remains immaculate. I took a look at the crack by the neck join, but it’s not too bad, and I’ll reassess it again once the neck is on. If I do anything, it’ll likely be a quick stabilising job using a little polished super glue.