Official Luthiers Forum!

Hi:
This is a varnish touch-up on the cedar top of a Spanish guitar. Clear varnish not tinted, some kind of poly or similar, not nitro or shellac. the customer brought it in because it had fingernail marks, it did not have a pickguard. (photo 1)
The standard solution would be to fill with varnish, level and polish.
I did several tests, If I use shellac, nitro, water base or superglue on the touch-up, this darken the wood (photo 2, test on the same top).
The question is, has anyone successfully repaired something like this?

Thanks a lot

That looks like the super glue. I’m guessing you tried that first. It will darken and change the colour of most soft woods.
It will probably be something you will have to live with. Welcome to the world of finish repair. I don’t have a remedy other than a top refinish, which I wouldn’t advise.

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Remember, there are no stupid questions, only stupid answers!

Cal, the picture is nitro, but it happen with shellac and super glue too. Now i am trying water base hot glue (fish glue) under and nitro on top. This method does not dark wood, but don't hide the varnish white mark.
"It will probably be something you will have to live with". off course!! I deal whit it a lot of times, resignedly, but now I loking for a new solution and figthing .
Could be somebody has the tip

Cal's right the only remedy that will remove that blemish for sure is to refinish the top and Cal is also right you don't want to go there.

You may be able to improve the look a bit filling, etc. but it will still be very visible. If completely gone is the goal it's refinish time.

I'm sorry I don't know how to refinish a poly scratch.... that's a very good question.

In regard to the dark divot, an interesting technique where you cut out a dish shape around the defect, with a gouge, and patch it, with a matching dish, cut from a grain-matching piece of cedar. http://frets.com/FretsPages/Luthier/Tec ... hole21.jpg Iris Carr has done this too...

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Measure Twice,

Karl Borum

We don't have an obligation to take every task someone brings in. Some can't be done, others have economics attending them which makes the job unrealistic. A job may be beyond the skill and/or experience of the person being asked to do the repair

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Peter Havriluk

Exactly right Peter and VERY important in the professional trade of Lutherie to be keen to avoid jobs that have what we call "scope creep" where the project keeps expanding and expanding into a thankless slog that you lose your soul and *** on. And it's not just about not getting paid for one's efforts it's the "opportunity cost" where a busy shop like mine if I get involved in some slog there are many other clients with gigs and deadlines that I can't help them with because I'm all tied up.

Before I became a working in the trade luthier I did what I used to do when I worked for GE I surveyed several dozen professional luthiers which included Rick RIP Turner who is who suggested I learn repair work.

Overwhelmingly the single greatest occupational hazard that working in the trade luthiers face is attempting to be all things to all people when some jobs are just to be avoided. We tend to be naturally helpful people who like a challenge. And that can result in taking in work that we shouldn't because of the opportunity costs to us and others, our client base and these days the repetitional hit when someone gives us a bad review.

Had this guitar come into our shop we would explain that invisible finish repairs on this one are not likely and not something that we want to get any of it on us. For someone we knew and had some trust established we might offer a functional but visible drop fill repair and if and when expectations were set honestly and realistically we might take it in, drop fill, scrape, sand, polish, buff and call it a day. But for someone we had no established relationship with we would have declined on this one.

On the forums someone will have a different perspective and that's fine. It's also why there are few pros here.... Our's is from a very busy shop with only two Luthiers who do about 1,100 guitars annually for nearly two decades now. We are very busy, there are waiting lists for us for the various jobs and we let people down when we get tied up in repairs where there is no certainty of time to complete.