I have a cheap-o GTX 4 string bass with rosewood fretboard which I've recently converted to a fretless. The fretboard is bare, just oiled, and I'm debating if I should epoxy it at this point (maybe that's the source of the problem). I'm using RotoSound Flatwounds (I think #66). The action may be set a little too high at this point. I still need to lower the nut slots to accomodate the missing frets. Sustain is basically close to none at this point. Notes don't hold for long at all. Is that typical for a fretless, or is it a result of my configuration? Any suggestions on what I should do to increase the sustain? Thanks for your help.