Leveling "Washboarded" Area of Top Prior to Refinish.

[Robbie Collins]

I have an old single-cutaway Guild Aristocrat in for a refinish. It’s been stripped and needs a lot of prep. I need advice on handling an area with what I call “washboarding.” On he horn of the cutaway there is an area where the softer wood has been rubbed away leaving the harder ridges standing proud. 

 The guitar looks to have a laminated top with a spruce veneer. I have sanded and scraped the area as much as I dare and now intend to level with superglue. I’m wondering if I should do this before of after sealing with shellac. I will also use shellac on top of the superglue so the finish will adhere.  I will be duplicating the original sunburst and the horn will be shaded fairly dark brown-red.

[Paul Breen]

Seal first! Super glue can darken unprotected Spruce and you may end up with blotches. Super glue used as filler will require some risky sanding, it's very hard when cured. I would take the time required to build it up with lacquer.

[Glen H]

Any chance the owner would be satisfied with just finishing it?  The leveling with ca just sounds like trouble waiting to happen to me.  It's just my opinion.  A nice shiny finish on that top would seems to make a huge difference.

[Ned Knepp]

I agree with Paul and Glen that trying to fill with CA is more trouble than it's worth. It's so hard that you risk sanding through the top ply trying to blend in the CA with the surrounding area. If it was a solid top, you can sand VERY lightly cross grain to even up the hard/soft rays then remove the cross grain marks with a hard block, fine paper and a light touch.  With plywood that's already been sanded, I wouldn't try it. 

I like the process of French Polish and this is one of the ways I use it. It builds very thin layers but they dry quickly so the wait to sand before the next round isn't very long. You might spray shellac but I haven't tried to fill this way. However you do it. I like shellac for this sort of thing.

[Robbie Collins]

Thanks for the comment, Paul. Lacquer would certainly be the cautious approach.

Glen - He doesn't expect miracles, but he expects me to take care of the low hanging fruit.

Ned - I like French polishing too but I usually brush on the build coats, sand level, then use the FP technique. I didn't consider filling the valleys with shellac because it takes so long to cure when it's thick.

So, I will avoid CA, seal the wood with shellac, then use thickened lacquer to bring level prior to shooting the toner coat. I could level it after the first set of clear coats, but I'm guessing a color coat over the washboarding prior to leveling will affect reflectivity and draw the eye.

[Paul Verticchio]

Hello.

Just an observation. With vintage instruments such as this, the original finish would have 'conformed' more or less to the shrinking virtues of the spruce top. This is VERY common on older luthier built high end acoustics.

It's up to your customer, but if she/he wants the guitar to look "new", you have a lot of difficult work ahead of you. However, if they want an 'age correct' finish [the finish will look like an unplayed or well maintained old instrument], it's a very acceptable plan to work. 

Personally, I'd use a correct nitro finish per your personal application schedule. THEN, to blend everything together, I'd use successive grades of rubbing compounds [as opposed to abrasive papers] to smooth & finesse the finish.The compound will 'follow' the wavy finish.

Personally, I consider the Guild Aristocrat an exceptional design and superbly executed guitar. Simplicity at its pinnacle. One has been on my bucket list for decades.  Unfortunately, others share my opinion and their prices have skyrocketed beyond my meager means. Even the superbly crafted reissues are lots of $$$$.

Best of luck with whichever method you choose. May I beg for "after photos" of the instrument?

Have a great weekend, Robbie :) :)