I have been a master carpenter for over thirty five years and we ALWAYS finished all wood on ALL sides to prevent warping.
I would think the same logic would apply to bed boards.
I am about to re-do my bed and intend to give all the boards at least seven coats of marine varnish on all sides.
Check back in ten years and I'll you know how it went :-)


1951 Chevy 3100 5-Window
"Howard"
In the Stovebolt Gallery
More pix on Photobucket