Separateing Bed Panels for Paint BACK SIDE?

[Clavo106]

Looking on how to paint the back side of my bed panels. I was thinking separating the bed panels in pieces then taking them to bare metal then bondo,, epoxy then arming the bed back together. now I dont no when or what time I need to apply the seam sealer . and another problem is welding the spot weld on the tailgait support.dont know if i could cut the new epoxy and weld with out desroying the new epoxy .. dont if theres more spot welds on the bed.. and not shure if the steps im taking or right. any help would work. I just would like to see the back panels painted when im underneath the truck.

[Clavo106]

[Clavo106]

when I was at ford we use to spray undercoating underneath new cars and truck. I dont remember the name but it came in a bottle u screwed nozzel on the bottle then connected the air hose then shoot.really thick.... but not shure if it would hold up to a 40+yr dirt and lit rust...