QUOTE (Sinisa Cekic @ Dec 16 2011, 10:49 PM)
Well, I guess the main problem for me was the way the reference points had changed. Generally when I set the action on a guitar I will use fret buzz as an indicator that I have gone too far. The concept of fret buzz doesn't really exist on a fretless, instead it is about finding a string height / tone that you are happy with - this introduces subjectivity which complicates things. Also setting the neck relief is a little different because of the lack of frets, without a straight edge to measure against it is easy to get this wrong. I find it more difficult to use the strings to measure the neck relief on a fretless because the reference points are different to what I am used to.
The way I generally do this is set the truss dead straight with a straight edge (really straight, like this one : http://www.stewmac.com/shopby/item/3850
) then adjust the action until I find something I am happy with. It is worth measuring the action you have set with a small accurate ruler and keeping a note of it so you don't have to go through the process of finding it again.
This technique works well with fretted / unfretted instruments I find and for me it is way more accurate than trying to set these things by eye alone. More importantly, I can repeat the process easily without spending hours fiddling.
As for filling the gaps left by the frets, I never bothered! Mind you, this is a bass and the strings are much fatter so it doesn't make much difference. With a guitar I am sure you would have issues though.
I would probably try and use the same stuff they make inlays from if I was going to do that though, then sand it flush.
Sorry for bigging up StewMac so much but they have this stuff too! http://www.stewmac.com/shop/Inlay,_pearl/T...3&xsr=22989
Hope this helps
Oh, and yes it did work!