I have a used 16' Alumacraft flatbottom jon boat. I would like to add a livewell and additional storage. I have attached a pic that i have added bracing and livewell to. My question is before I started, the boat would have a 1100lb weight capacity. After I would add the aluminum bracing, floor, and other materials needed for the mod. I figure this will add about 400 lbs when the livewell is full. I was wondering if expanding foam would add buoyancy to the boat and if so where to put it. Dont know if this would be a good Idea have not even added the weight of the motor, steering system, gas tanks, trolling motor and electronics and batteries. Just curious if the plan would make any sense. Would appreciate any response.