Classical fretboard taper and bridge/action problem

[Kim de Rijke]

Hi there,

It seems the only contribution I make to this wonderful forum is asking advice as a result of stupid mistakes. I suppose it comes with the fact that I'm a relatively new amateur builder. Just to introduce myself properly - I'm in Brisbane, originally from Holland where I built my first classical guitar with my teacher (who also taught me how to play). Because I migrated to Australia halfway through the build and found it difficult to find work (and fund a trip back to Europe), the guitar took another 6 years to finish! I have since completed my first solo classical, some photos of which I posted here last year. I am now working on my second when I have some spare time in between my research job at the University, young kids, and everything else that demands attention.

The problem I now have is this: I just glued down the fretboard and then checked the height at the location of the saddle. I'm following the Cupiano and Natelson dimensions, and they suggest no less than 3/16 inch clearance at the saddle location. I have 3/32 and a bit. The reason is two-fold: my fretboard is on the thin side to start off with, and I made a gruesome mistake while attaching the soundboard to the neck. I thought it was safe to leave the soundboard proud of the neck and then sand it back when gluing on the fretboard. It was proud a bit too much (well, that turned out to be an understatement), but still decided to hit it with the sanding block. What was I thinking? Was I thinking at all, I can't quite remember This means the fretboard sort of sunk into the soundboard, adding to the reduction in height at the saddle.

What can I do best? I know this guitar has suffered irreparable damage but I'm going to finish it regardless. They are all good lessons I suppose. Can I reduce the height of the bridge by about 3/32, and have the saddle just above the slot to compensate for all of this? What will the implications be? Should I remove the fretboard and add a few layers of veneer to raise it? The soundboard isn't thick enough to sand back, so I'm not sure what I can do there. Something else?

Thanks,
Kim.

[charangohabsburg]

[...] they suggest no less than 3/16 inch clearance at the saddle location. I have 3/32 and a bit [...]

Hi Kim,
Which distance exactly do you (Cumpiano/Natelson) mean by clearance at the saddle location? The mentioned 3/16" do not make much sense to me for any clearance associated with the bridge, surely I am missing something.

Regardless of which measurement it actually is I understand that with a too thin fretboard the strings would end up too close over the soundboard at the bridge location, which seems to be your problem.

[...] Should I remove the fretboard and add a few layers of veneer to raise it? [...]

Getting off the fretboard and beefing it up with a shim of fretboard- or neck-wood, or also making a new fretboard sounds like a good solution to me.

Don't reduce the bridge hight too much, the strings should not end up lower than 9-10 mm (classical) to 7 mm (flamenco) over the soundboard.

[jeffhigh]

Hi Kim
Well you have a bit over 3/32 so 2.5mm at the bridge
add 1mm for frets gives you 3.5mm
add average string height 3.5mm at 12th x2=7mm gives you 10.5mm
-0.5mm for neck relief under tension gives 10mm

you might be ok is you have a low bridge and the body is not too flexible