Originally Posted by 96tbird
They are simply called lines or fret lines. What you need to do is add a drop of super glue to that and sand it flat with a radius sanding block.
A quick fix for a Luther, just a bench charge maybe half an hour.
Also a GREAT learning project. A custom neck and body may be good rather than bad depending on the wood, construction etc. It is very much like my $10 bass! I bought some Bart pickups off a TBer and he threw in the whole fretless bass with them for $10 more!! I figured parts, but when I got it the bass was so close to cool (missing electronics and neck had problems). So I decided to fix it.
The "lines" on the neck are usually the grooves where frets go that have been filled with something. The best is strips of wood veneer. Yours does look like that. Worst is wood filler that has no strength. Those lines need to be filled to keep the neck from loosing strength. That high "line" seems to be one that may have come unglued and is raised high. It looks like someone tried to reglue it.
First order of business is to make sure your fillers are strong (wood etc) and are all glued in properly (not loose in any part) As suggested you can reglue them by flowing superglue onto the loose ones and letting it flow in. If the lines were filled with weak filler I'd just get a fret saw and clean them out an refill with something strong (epoxy, veneer, etc)
Once you are sure all the fretlines are stable, it's time to attack the neck. Loosen the truss rod and see what the neck curvature is. Look for twists and the like. We will assume there are none. Then tweak the truss rod to get neck as flat as possible. Just lay a ruler on it. (You'll have to take the nut off too! They are usually glued but should pop right off, but it's not unusual to break one either. If you break it, I suggest buying the right size Graphtech black TUSQ lubed nut. They are GREAT.
Ok. Now you need to determine the curvature of your fingerboard. That takes a special tool. So there is going to be an order to Stewart-macDonald here. I bought the understring type #0353. If you don't want to spend the money you can download printer ones you cut out from pickguardian.com. Personally I URGE you to buy the gauges. They make things so much more accurate and easy. At the same time, even though this is a fretless job, I also URGE you to buy a "fret rocker". It is used to find and test high frets on fretted basses. As for the straight edges and things you can find plenty of metal yardsticks etc around. No need to fork out a bunch of cash for that.
But wait. Your Stew-Mac order isn't done yet. Once you carefully measure the radius of your fretless neck, you'll need to order a wood radius sanding block in that curvature. I use the 8" length and numbers run from #0403 to #0415 depending on curvature. Yeah fifteen bucks is kinda high for an old block of wood, but hey that proper curvature in it is ESSENTIAL to the job.
And if you need to clean out fretlines and refill them a cheap fretsaw may be needed too. I doubt this will be the case, though.
Then the "fix" is merely sanding your neck smooth and completely flat. Start with coarser grades and work to a nice fine grade finish. Then treat the neck with a commercial fingerboard oil like Dumlop or Fret Doctor. Lemon oil will work but I think the pro treatments work better just after a sanding.
Put the bass back together and string it up. I would not glue the nut in place until you have tested the bass and found it to your liking. Then use a couple of TINY drops of super glue to hold it in place. Check the relief under the strings when pressed against both ends of the fingerboard at the same time. It can be set from exactly flat to a slight normal curvature relief. The flatter you set it the more mwah the bass will have. But also the more likely the neck will develop a buzz somehere along it. Watch out for S curves in the neck showing that it's lost strength due to defretting.
You'll love it. I know I love my $10 fretless that was turned from junk parts into a killer bass with just the above operations I described. Yes the proper tools cost some coin but then you'll have them for ALL your basses including the next ones! :-)