End grain planking direction

[tcoppinger]

I'm starting to cross plank the bottom of my flat bottom skiff with 3/8" yellow pine. The wooden boat school in North Carolina said to place the planks with the end grain/rings of the wood facing down. The wooden boat building book I have says the opposit, to place the rings facing up. Any suggestions?

[maa. melee]

Quoting John Gardner "Slash-sawn boards, [...],tend to cup toward the outside of the tree when they dry out and as they age. Thus, slash-sawn boards, [...], should be put on the boat with the outside, or bark side, inside so they will cup toward the inside of the boat, giving a smoother bottom with less drag. The wider the bottom planking used, the more important this becomes."

[Bob Smalser]

I prefer riftsawn wood for this but have done them before in fleet skiffs with flatsawn boards with ring cups upward.

Circular growth rings like to straighten themselves out with seasonal movement. That way if the planks cup on you, they cup with the board edges applying pressure on the chines, which affects the planking seams the least.

Do it the other way, fastening the planks with growth rings cupping downwards, and any boards cupping on you will pull the seams and seam fasteners away from the chine, the worst of the two possibilities.

Again, for as little as you need, riftsawn wood is the way to go. It moves less, so you can get the planks wetter between trailerings with less risk of the seams opening up.