The Arleigh Burke class destroyer was printed in FDM filament (early days before resin 3D printing was common). This material is not really good for modeling. The lines of the filament are visible and the nylon-like material does not sand well. Many coats of primer and much sanding got it looking decent, but not good. Fortunately, there wasn't much surface detail to begin with so nothing much was lost through all the filling and sanding.