The first bow I ever made was a red oak board bow.
The second was a red oak stave I had harvested myself.
I used the same dimensions on both bows. They ended up 68'' long, 66'' NTN, 50-55 lbs at 28''
They are both 1.5'' till mid limb and then taper out to 3/8'' on one tip and 9/16'' on the other
The Board bow finally broke about 4 inches from the tip. I think I made it slightly to thin
But it took three years to brake.
The stave Bow I still have and shoot. The plans I used were from the American flat bow.
Keep in mind I did back both bows with linen and a nice amount of titebond III
http://www.vintageprojects.com/archery/Flatbow-plans.pdf.
Hope this helps