Please explain. I know in boat building, red oak when placed in water with the grain running vertical it will draw a lot of water. Is this the same/similar issue with furniture making ?
Red oak definitely has issues with water.
The structures of the wood are hollow and water will wick right through it.
If you put a short length of red oak in water lengthwise, you can actually blow bubbles with it.
Never use red oak in an outside application.
I much prefer the characteristics of white oak better.
It is more dense, the ray fleck is much better than red oak when quartersawn , and it is traditional in mission furniture.
Not as important but I just do not like the smell of red oak while working with it vs. white.
To answer your other question about the back....
The back is all white oak 1/2" thick.
It was cut with rabbets to overlap aka shiplapped.
Thanks!