Currently renovating 18x36 IG poly wall (42"). Pool is 30 years old. Has not been filled for at least 10 years. This is the only significant issue with the poly wall. How would you repair? The panel is quite solid, even right at the crack. Concrete deck above is in good shape. Thanks for your suggestions. I should mention, I will be building a vinyl over bench along this wall, however the crack is at the top of the panel.