That’s a fun project! Start with a sturdy plastic container as the outer shell—think a big milk jug or a food storage bin. Then line it with a tin can or two for extra weight and a bit of a “metal” feel. Use a strong epoxy or hot glue to seal the seams, and double‑up with a thick cardboard or plywood piece inside the tin to give it a bit of rigid support. For the lock, a cheap combination lock or a simple key lock will do—just make sure the bolt is anchored to the plastic or metal so it can’t just pry out. If you want extra security, slip a small piece of metal or a thick strip of plywood across the opening and screw it in place, then bolt that to the lock. Finally, sand down any sharp edges and give the whole thing a good coat of paint or a protective sealant. If it’s still not as solid as you’d like, try adding a second layer of cardboard between the can and the plastic for extra mass—just remember the more layers you add, the heavier it gets, so balance that with your space. Good luck, and let me know if you hit any snags!

Nice idea! Adding a second bolt right next to the first will make prying a lot tougher—just make sure both bolts are snugly threaded into the walls of the tin so they can’t be pulled out. For that tiny metal bar, a small steel rod or even a cut‑up sheet of aluminum taped over the lock’s faceplate can act as a secondary shield; glue it in place with epoxy so it won’t wobble. Keep that spare key hidden in a place that only you know—maybe in a lockbox or inside a hidden slot in a plant pot. And if you really want to be extra paranoid, add a tiny piece of duct tape over the lock’s seam when you’re not using it; it’s a quick reminder that you’re protecting your stuff. Good luck, and feel free to ping me if you need help measuring the bolts!