i apologize for the cross-post on the board (i've posted in setups, but i'm dying for an answer)... ------------ greetings TBers... I'm working on fixing up a (Andy) Schack bass. Basically, the problem is that there is a severe back bow (to the point were an open string will not resonate at all). I've tried raising the string height and I've loosened the truss rod as much as possible, but the neck remains back-bowed. There is a zero fret on the bass so I'm guessing that a nut shim would be rather pointless? I've even tried clamping the neck with a straightedge to straighten it and left it for 24 hours...this didn't work. This afternoon, I tried clamping the neck to force it into an upbow and left it for several hours and this seemed to help a little bit but before I go and apply all sorts of pressure to the neck in various spots, I figured I'd check in with you guys to get some suggestions. The bass is at the shop where I work at for the weekend and I plan to resume work on monday when I have all of my tools. Can anyone offer up any advice on how to rid this bass of its back-bow problems? - someone commented on string tension as a possible problem and then i wrote... The string tension shouldn't really be an issue though. The bass was fine at one point...and then for some reason, the neck warped. I've been thinking about it and perhaps i could clamp it into an upbow with the rod rather loose and then tighten the rod to straighten out the neck and then add propper relief? I haven't figured out yet the best way to clamp it into an upbow though. I'm thinking that I can MacGuyver up some sort of rig where i have a level clamped to the center of the neck and then somehow add more pressure upwards towards the headstock with some clamps and some blocks of wood, but I'm affraid of destroying the neck. Also I've been thinking another idea could be to clamp the neck totally straight with the truss rod fairly tight and then try loosening the rod to add some relief? But again, I'm affraid of destroying the neck. What would anyone recommend (and please don't suggest bringing it in to a repairman...I use these forums so that I don't need to do that any longer). ANY and ALL help is more than appreciated... Thanks for reading and I eagerly await a reply!