Surplus ammo cans come in numerous sizes. They are readily available at army surplus stores for reasonable prices. The metal cans are waterproof and sturdy enough to haul plenty of metal tools and spare parts. We like them for spare fluids as well, as any spills or leaking bottles are contained. We’ve also used them in vehicles as consoles and interior storage. Bolt or weld one end closed and add a hasp eye to the other end and you can have lockable storage.