Acoustic Guitar Construction

First time that I've had this problem - I cannot, even by loosening the truss rod completely, get any relief in my neck.
Got ideas/solutions?
Thanks

I assume this is on the "F" hole project? You can try tuning it a half or whole tone over concert pitch and letting it sit in a room that has your average RH for two or three days. Take measurements at the 18th fret before and after -- you need to see if the bridge is rolling and pulling up your "A" frame and not providing enough or equal resistance to string tension to pull the HS toward the sound-board. What kind of neck did you use? Truss rod?

Yes it is the f-hole. Single-action truss rod and neck, that I pulled off one of my older kit guitars to use on this for the time being.

Okey-dokey, tuned up full step higher, measured at 18th fret, I'll leave it be for a couple of days and post the results.