Solidify Hollow STL Model ASAP

I have a single, hollow STL that must be converted into a fully solid, watertight file ready for 3D printing. There are no special wall-thickness or design constraints—just make it truly solid so it slices without errors.

Time is critical: I need the finished stl file within 8 hours of awarding the project, so please accept only if you can begin right away.

Deliverable
• One solid, manifold STL that passes standard print checks (no holes, non-manifold edges, or self-intersections).

I normally inspect models in Cura and Meshmixer; if your file loads cleanly there and shows 0 mesh issues, we’re done. Feel free to use Blender, Fusion 360, MeshLab, or whichever tool you prefer, as long as the final result meets those checks.