My Typhoon is double planked with the final planking being 1/4 and 1/8th inch wide Mahogany strips. The hull is like glass.
The 1/8th is for the areas that have more of a curve.
It is time consuming. For best results each planks edge should be slightly beveled to insure a tight fit. On full sized boats this was called spiling the planks.
After sanding to achieve a fair hull, it should be coated with a sealer, thin epoxy is my choice. Then coated with a heavier coats after sanding between each to achieve a smooth finish