Wooden Pool Question

I am casually considering building a wooden pool. It will have about (16) vertical 4x4 posts as the main supports secured to cement footers about 3 feet deep. All these main posts will be joined together by horizontal 2x4s. This will be the main frame. I will then buy a ton of vertical planks 2"x6"x52" to form the pool wall. Basically these will replace the steel wall of your normal above ground pool. My question is, I don't like the idea of a pool liner against wood. So I plan on putting a layer of wall foam between the wood and pool liner. Any one have any idea if the wall foam will be good enough to protect the pool liner from the vertical wood planks? The X's below crudely represent the 4x4 vertical posts. the dashes represent some of the 2x4 horizontal beams. Its a birds eye view. I did not show any of the 2"x6" veritcal planks. But if I did they would wrap around the inside of the entire oval.

x-------x-------x-------x
x x
x x
x x
x x
x-------x-------x-------x

I would think the foam would be good enough. When my IG was redone in 97 a layer of foam was added between the liner and steel walls. The foam has compressed over time but still offers good protection from rough spots.
Al

thanks for the info. It appears my little diagram did not format properly so ignore the X's on the left