How to square off the end of fretboard on a kit neck that isn't quite right?

Cano

I've just got a body & neck only kit for a Les Paul DC build. I have an issue with the neck where the nut end of the fret board isn't cut square so as it's currently stands I can't go ahead and fit the nut until I've fixed that.

Now, I believe that the bass side is too long and that the treble side is the correct length. Initially I thought it was the other way around but comparing with my other 24.75" scale LP kit it's looks like the short side is the correct length.

What's the best way to fix this? I know I need to file the end of the fretboard square but what is the best technique to ensure I get the perfect line parallel to the frets/perpendicular to the neck centreline?

I'm doing this build at home, so have no access to workshop and limited tools. Just some clamps, files, rulers and a rasp.

Thanks,

Cano

Funkfingers

You know the rules. You can cut more off but you cannot put any back.

Your example is a strong case for one of those Earvana adjustable compensated nuts.

SteveRobinson

Easiest might be to stick some coarse abrasive (e.g. 80 grit) to one face of a block of wood and carefully sand away the excess.

Keep the block flat against the nut shelf as you go.

Cano

SteveRobinson said:

Easiest might be to stick some coarse abrasive (e.g. 80 grit) to one face of a block of wood and carefully sand away the excess.

Keep the block flat against the nut shelf as you go.

Thanks Steve, I can give that a try. I have a small square section piece here that looks like the perfect candidate.

If that was successful in correcting the end of the fretboard, what would I then need to do for the bottom of the nut shelf, the mahogany that is currently covered by the rosewood that I need to remove. How is best to make sure I have the perfect surface for the nut to sit on without damaging the smooth (but misaligned) surface that is already there?

Roland

Before sanding I’d do the following:
1. Measure from the top centre of the first fret to the edge of the nut. In your case measure at both 1st and 6th string positions because it’s least askew.

2. Check the scale length of the guitar. 

3. Look up on the internet what the distance from nut to first fret should be.
4. Go back and measure it again because you can’t believe your first measurement was so different.
5. Check the scale length, position of 12th fret, and probably a few other frets because you’re now worried about the geometry of the whole neck.

6. Look up bridge offsets on the internet to see how far wrong the scale length is
7. Take a break.

None of the above is cynical. Ask me how I know.

If the treble side distance is too short then send the kit back for replacement or refund. No quibble. It is not fit for purpose

If the treble side is OK, or too long, then you stand a chance of doing it yourself.
1. To remove the nut. Run a sharp knife blade along the edge with the headstock to provide a clean edge to the varnish. You don’t need a lot of pressure. Do the same along the edge with the fret board. Then put a short length of wood against the fret board side of the nut, and tap it with a hammer until the nut comes loose. If it doesn’t come loose easily, or snaps, then buy a new nut.
2. Measure the edge of the new nut position.
3. Check your calculations, then measure again. 

4. Mark the new position with a sharp blade drawn steadily across the neck. Pulling the blade lightly across several times is better than pressing too hard and slipping. A blade is more precise than a pencil line. It also slices the fibres of the wood surface to that they are less likely to splinter.
5. Put a piece of tape tightly around the neck on the neck side of your line. This helps to stop the wood splitting or splintering as you cut or sand.

@steverobinson has more experience than me, but looking at the angle shown in your picture I’d consider cutting rather than sanding:
6. Support and clamp the neck so that it won’t move while you’re cutting. 

7. Get a fine toothed blade. Chances are you haven’t got a fret slot saw, or a Japanese pull saw. A junior hacksaw will suffice. Pull, don’t push, the saw to cut through the fretboard on the head side of your line. The first few strokes are the important ones because they set the cutting line. Make sure that the blade doesn’t skip or slide sideways. Focus on accuracy rather than wood removal ... and of course try to keep the blade perpendicular to the neck.
8. Whilst sawing check constantly the you’re not cutting too deeply on either side.
9. Once you’ve cut down to the neck wood you might need to use that sharp knife to remove the cut slice. You will certainly need to use the knife to clean up the surface because chances are that you will have cut to the right depth on either side, but left a 0.5mm hump in the middle.
10. Celebrate with a cup of tea, or something stronger.

WezV

Looks to me like there is a gap between nut and fretboard on the bass side.

If that's the case either doubt the board needs cutting or sanding at all, just the slot tidying up with Steve's method so the nut sits right against it

SteveRobinson

Yes, use the same sanding block to level the shelf for the nut. I'd do this first before addressing the end of the fretboard

Cano

Thanks Roland.

Firstly, the nut isn't actually fitted yet, I just placed it in position in that photo as it makes it very clear that the fretboard isn't cut straight - so I don't have to worry about removing  a glued in nut thankfully!!

I went through the exercise of looking up fret distances and measuring, checking again and measuring again yesterday. I then did the same on the 3 other Gibson scale length guitars I have here only to find that one of them (Gretsch) has different fret distances to the others  

At that point I also learnt that my digital calipers are junk and randomly lose their position when measuring. Fun fun fun.

I resorted to taking the new neck and holding it side-by-side with my other completed LP kit, confirming that the fret distances on both necks are the same and also that the short side of fretboard on the new neck lines up with the Nut on the other guitar perfectly.  That's where I landed on my current belief that the bass side is too long rather than the other, far less salvageable scenario.

It's long by about 1mm so I am minded to go with the sanding option given any blade I use will be too close to 1mm in thickness for my clumsy hands not to screw it up.

My biggest issue here is the kit is from an eBay seller in China so returning it for a replacement is just not a great option. This kit took almost 2 months to arrive so I don't think I have any chance of getting a replacement this side of Easter.

I'll keep measuring and thinking before committing to any cuts - I don't think I'll be attempting anything until next week.

Cano

SteveRobinson said:

Yes, use the same sanding block to level the shelf for the nut. I'd do this first before addressing the end of the fretboard

Oh there is already a levelled shelf for the nut, I'm just thinking that I'll need to make sure that extends lower once the fretboard is cut back.

ICBM

Wow! That’s hilariously off square…

I would do exactly what Roland said.

Cano

WezV said:

Looks to me like there is a gap between nut and fretboard on the bass side.

If that's the case either doubt the board needs cutting or sanding at all, just the slot tidying up with Steve's method so the nut sits right against it

I've tried to take a photo that shows the angle. The difference is small, it's around 1mm but as soon as I see it, just looks extreme with the nut in place.
https://i.imgur.com/4P0SCXe.jpg

BillDL

It might be a good idea to document your progress and take photos at various stages.  I am fairly new here, but I can see that some of the long standing members organise regular chalenges, and the latest one is building from kits:

https://www.thefretboard.co.uk/discussion/219545/a-new-challenge/p1

TJT1979

I’d do what Roland said but after scoring the new line with a scalpel I’d use a chisel to cut to that line. The scalpel cut will provide a solid safe position to lock the blade of the chisel into. At the thicker side I would first remove a bit of material before doing the final cut using the line. If the last cut is less than 0.5mm a sharp chisel should slice though that end grain fairly easily. 

andy_k

Times like these are when the addition of a decent Dremel to your toolkit become a thought.
Working on the nut end of a neck or fretboard is always extra tricky, due to the issues around clamping and holding the neck.
In an ideal world, the neck would be held flat in a jig which would allow some sort of sled to ride a dremel router base on.
This is the problem that has held me back from attempting to fit FR nuts, on multiple occasions.
A more realistic case, in this scenario, is to do the steps already mentioned re- measuring, measuring, scoring, shaving and sanding, which is made more difficult by the clamping problem I talk about, it is hard to get any pressure with a sharp blade, or chisel with the neck not being held securely, and sanding accurately is also difficult.
I'd almost suggest getting an accurately made brass nut, with a shelf cut into it to accept the fretboard error, but that's just me.
An Earvana nut might be a cheaper method, but I'd expect there will have to be some wood removed to get it in the right place.
Good luck, however you proceed.

Jono111

With your digital caliper it may be worth removing the back and insulating the back cover  as on some cheaper ones the PCB shorts on the casing when in use and alters the reading. Doing that fixed my Aldi one anyway.

Roland

Jono111 said:

With your digital caliper it may be worth removing the back and insulating the back cover  as on some cheaper ones the PCB shorts on the casing when in use and alters the reading. Doing that fixed my Aldi one anyway.

Wrong thread?

Cano

Roland said:

Jono111 said:

With your digital caliper it may be worth removing the back and insulating the back cover  as on some cheaper ones the PCB shorts on the casing when in use and alters the reading. Doing that fixed my Aldi one anyway.

Wrong thread?

No, I think I said earlier in this that my digi calipers have a mind of their own. 

Funkfingers

Digital callipers might measure the manufacturing error but knowing the extent of the error contributes very little to the cutting/abrading task. 

Further, for any measurement comparison, the callipers need a reliable datum point. On a guitar, the nut is the datum point. Measuring from, say, the first fret back to where the nut ought to be is not sufficiently reliable.

Trial and error and patience is the way.

WezV

Funkfingers said:

 

 Measuring from, say, the first fret back to where the nut ought to be is not sufficiently reliable.

Why not.   You have to allow for the fret width, but that's easy enough if you already have the calipers.

Measure the width of the fret wire, half it, take that off the correct nut to 1st fret distance.

Although finding the correct nut to 1st fret distance can be a challenge if its an unknown scale.  You can still work backwards from the 1st-13th (or any other  known fret distances) measurement to figure out what it should be.

Cano

I've removed that fret today, so I'll can measure it exactly now (the tang had only been trimmed on one side, hence the lifted end) 

WezV

Just bear in mind that if its sold as 24 3/4" it's likely a close metric equivalent of that.   

It robably won't be exactly 24 3/4", and its highly unlikely it will be any of the other measurements or calculations gibson used.

Well worth checking a few other fret measurements.


Also, there is a little fudge room with nut to 1st fret.  Many remove an extra .5mm from this distance to give a little compensation