The power plant is a Rebuilt Chevy 350 with 10 hours on it. How would I go about getting these core samples? And if they provide bad news, would I be wise to scrap the whole show?
take a 1/4" drill bit, a cordless drill and a piece of tape
put the tape 3/4"-1" from the end
now starting in the bilge, drill into the stringers about 1/2" up above the hull to the tape, make about 3 or 4 drills on each side
also drill into the transom from the inside the same depth, about an inch above the hull, starting about 3" from the keel drain and moving upward, making about 3 or 4 drills on each side of the keel
if the shavings are light-colored, dry and smell like drilled fiberglass and fresh wood, then simply patch them with marine tex epoxy putty, buy a lottery ticket and go boating
if the shavings are dark colored, wet and smell like moldy rotting wood.....pull the motor and start gutting the hull for a refit.
sometimes you will drill and not find wood because it rotted away years ago
sometimes you will drill and water will start coming out
sometimes you will drill and a bunch of carpenter ants will start coming out.
I like to drill thru the stringers to the flotation foam on the other side. many times it will simply start pouring water.