Removing scratches on an ebony board

[tadej bratkovic]

What's the best way to remove scratches left by utility knife, the customer was using to remove crud where frets sit on the board. It's purely cosmetic and does not affect playing. If this only gets tedious, I can leave it, oil it and return it, judging by his fret wear the guitar will need a refret in a year or so anyway.

I also carry a polymerizing gunstock oil so would it be good to wet sand with it and then rub the emulsion in? I bet this ain't a long-term solution, is it?

[Mark Pollock]

My 2 cents, and you should probably get a discount on that...

I assume there are bunches of scratches on both sides of the frets, parallel to the frets.

The right way to do this is take the frets out, sand the board, and put the frets back in. I'm pretty sure that is not what your customer wants.

Unfortunately, this really needs to be sanded with the grain to eliminate the scratches, and you can't do that with the frets in the way, at least without damaging the frets a lot. I would tell the customer to keep the knife away from the instrument and use an old credit card next time for cleaning, and to get the damage repaired when the instrument gets refretted. Or just do the refret now and get it all fixed at once.

[Frank Ford]

I faced that issue for the n-th time recently, and finally made a "tool" that does the job.  I use the quotes because it's really a set of sanding blocks, not a single item.  My new little blocks are 3/16" thick, and fit between the wides and narrowest frets.  In that range, I made blocks in roughly .025" increments, so I have a block that fits neatly in any fret space.

With such blocks, it's not only possible to sand across the grain, but reasonable as well.  By scrubbing with 320 grit, and changing paper often, I produce only the finest scratches, and no unevenness.  Once I sand across the grain that way, I can carefully sand and scrape with the grain using tiny blocks and finer paper to make things look quite nice.

Unless you use a block that fits the full width of the space, it's virtually impossible to do a neat job of sanding aggressively between frets.

[Mike Kolb]

In my daydreams, I've wished someone would make a set of scrapers along the lines of what Frank has described. They would be radiused ...say 20", to cover the majority of most given radii without too much tilting required. 

Maybe they wouldn't be all that difficult to make-up at home, but StewMac could have a ball offering different sets of sizes and such.  Just wishin' again....

[Hesh Breakstone]

Did someone say scrapers!

I use single edged razor blades as a very fine scraper in between the frets.  With a little practice on say a beater guitar you can get pretty good at this and learn how to avoid chatter.  The scraper/razor blade will take off/down scratches quickly and with good lighting and your great eye sight.... you can concentrate on the problem areas and remove more material as needed.

The sequence for me is that I typically do this step, freshening up the board, after I am done installing, gluing, leveling, and crowning the frets and also shaping the ends too.  Once all the tools have been used, things that can leave a mark when you slip or because we are recrowning some very low frets I get out a fresh single edged razor blade.  It also makes fast work of the glue that I use to glue in my frets too.

After scraping the board, and a single edged razor blade fits between any fret location as-is, is when I do the traditional method of using successive grits of folded sand paper to remove fine scratched on the sides, tops of the frets and any minor marks left from the scraping.  Usually after using the first (coarsest) grit if I have any more scratches on the board they show up very well and I might hit that area one more time with the scraper, single-edged razor blade.

My technique with the razor blade is back and forth, not just in one direction, and the frets act as curbs to contain the scraping action.  It does take a little practice but the learning curve is very fast and you can literally see the scratches become history in a few strokes, depending on how deep that they are.

[William F.Eden]

I do it the same way as Hesh and have the same luck and you don't end up with more scratches  to try and get rid of.Bill............

[Mike Kolb]

Good detailed description of the procedure, Hesh.... it's pretty-much what I do as well, and that's what got me to daydreaming about a scraper that would be a bit wider than a razor blade (to cover the area in one or two swipes) and radiused as well.  

StewMac... you listenin'? :)

[Frank Ford]

Scraping is a great way to avoid and remove abrasive scratches, but if you need to go very deep to level bad scars, there's little chance of producing a level surface between the frets.  If you scrape heavily, you'll typically end up with a wavy surface that will show in reflected light.  

I use scrapers of all kinds, and may clean up new work with some gentle razor blade strokes, but I find they're not up to the job when trying to rework a truly messed up fingerboard scarred from an old job without removing frets.

[Mike Kolb]

So, after doing some head-scratching, here's what I've come-up with.  I sacrificed (well, just shortened) a few wooden sanding radius blocks and cut some sandpaper to fit.

Now the trick is to remember where I'll have stashed 'em when the next appropriate job surfaces :)

[Mike Kolb]

... just tried one out on an old wall-hanging beater.  They work well, once you get the hang of holding them firmly from the bottom, as they have a tendency to tip otherwise.  Maybe I'll cut them down from the top to make 'em, say, just about an inch tall.

A work in progress, but there's something there. To be continued. Hope everyone had a happy Labor Day :)

[lonnie james barber]

StewMac has an ebony type product epoxy, I got some and mixed it real well. It is supposed to be slow setting up. Anyway I applied it. It was very loose,actually ran all over the place leaving holes etc. Not like any epoxy I have ever used before. If I was to try it again I would allow it to almost jell before I applied it. I however just used the bare blade of a utility knife Lifted right up like it had no adhesive value at all. It really surprised me as I've been a long time customer of StewMac this is the only time their products failed me. Regular epoxy with a light sanding followed by Ebony dye should take care of it.Regards Lonnie

[tadej bratkovic]

Thanks for ideas guys, we have decided to leave it. We're planning a refret in the coming year so right now it's not worth it. I put much effort in leveling the fingerboard itself and I don't wanna cramp it now and maybe leave ramps under the frets.