A demonstration of how I built self supporting bank turns 20 years ago.......The surface was 1/2" partical board the wood strips from 3/4 plywood ripped into 1 1/2" strips, and 1/4" plywood for the backer sheet......it holds its shape before the sidewalls are applied. .....
The model is made from 1/4 ply but the concept is the same.....
On the full size piece I used a ratchet strap to bow the turn.....
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