Dead frets after shimming

It has nothing to do with the shim and everything to do with the height of the strings over the frets. That clearance at the 12th fret is quite low - I assume you are measuring between the bottom of the string to the top of the fret, not the top of the fretboard as you stated. Assuming you meant top of the fret, you will need very even frets to get it buzz free with 1.75mm clearance and you will need a light touch.

 

The bass has been de-fretted, as he said early on in his post.

 

You have indeed discovered that your fingerboard needs work up there. You've likely got a bit of a 'ski jump' happening. The cure is to level and maybe even (my preference) cut in a bit of upper-level 'fall-away.'

 

Sorry - misread the original post. 1.75mm is still quite low. And you will need a really level board at that height. It can be done, but fretless is even more demanding than fretted - on a fretted instrument the space between frets doesn't need to be level, just the fret tops. On a fretless every mm along the length of the board must be level. And as with a fretted instrument, the lower you want the action, the more critlcal it is that the board is really level. And the shim is still not contributing to the problem.

 

Nah, you just discovered your fingerboard isn't as level as you thought when you lowered the string height.

In @Turnaround 's defense, the title of the thread does say "Dead frets"!

 

Neither shims nor micro-tilts cause ski jumps - it's a myth.

 

This is why measuring is pretty meaningless.
Use your ears. Raise your strings until you don't have an unacceptable buzz on any frets. That's the lowest you can go without leveling those frets.

 

Bloody unlikely. But if you want to be sure, use a thick full-length shim instead. Rather that tilting the neck it will raise the neck evenly. A little harder to pull off but will give the same result (lowered action) as a back shim.

 

He did use a full-length shim.

 

You bet!

 

I agree with others that you've now pushed your action lower than the flatness of your neck allows. You need higher action and/or a flatter neck. 1.75 mm is about .068", which is quite low.

.080" or so is about where I run my D and A strings.

 

Down here in SE Virginia, if you pull your car onto a railroad crossing and kill the engine, the ghosts of Confederate soldiers will push your vehicle out of harm's way.

Riis

 

I said thick.... not tapered. But I suppose it doesn't matter either way..

 

Pretty sure StewMac shims are all full length.