About a week ago I had an idea… not an original one. I don’t know why I haven’t tried this until now, but I realized that I could probably shape limestone with a harder river rock… so I found a reasonable sized chunk and started shaping it. I’m using nothing but water and a river rock as tools.  It’s still a work in progress, and it takes some elbow grease, but it’s a simpler process than I expected.  Next I need to figure out how to capture the limestone mud, then cook it to make lime… then maybe use that to make my own concrete from scratch… but that’s a fairly nasty and potentially dangerous  chemical process.

Blindsquirrel wrote on Mar 12^th, 2023 at 1:53pm:


I could… but it would probably end up more brittle and less dense than a shaped rock…. Plus, good luck building a mold using nothing but a river rock. I’m doing it for the challenge rather than optimizing efficiency.

Here’s another progress photo where you can see how it takes shape and how it loses mass.  It’ll probably be under 100g when finished.

I understand wanting to push one’s limits with a challenge. For a mold from nothing, find a well shaped rock and use it poke a hole straight into the ground for ur mold? if u burned ur limestone u make quick lime which crumbles and grinds very easily. Quicklime is also the main ingredient for ancient concrete. I believe this is Why so many glandes r found by the water or in the water,  these r ones that were in the various stages of the curing process. the longer concrete is in water the harder it gets, the slower u let it dry the stronger it becomes. And Roman concrete seems to be very durable. I believe there r still building of theirs standing to this date.

If I remember right, the slingers of the Balearic islands used limestone balls during the timeof Rome. Tey were supposed to be about the size of a pool ball. That would be quite an impact.

IronGoober wrote on Mar 13^th, 2023 at 7:49pm:


Yeah… I should’ve picked a slightly larger piece 🤷‍♂️

Rat Man wrote on Mar 13^th, 2023 at 8:56am:


If anything, the problem will be how soft rather than how dense, but I think this thing would still do some damage.

That's looking great!

So the big question, when it's done are you going to sling it?

joe_meadmaker wrote on Mar 15^th, 2023 at 8:51am:


Of course!

Blindsquirrel wrote on Mar 17^th, 2023 at 8:01pm:


Not a terrible idea… or I could just spend another two weeks grinding another one from another piece of raw limestone 🤣

I got down to 100g and it still has a few flaws, but I don’t really want to go any lighter, so I’m calling it good.  Next, I’ll oil and bake it for a tougher outer surface (just like seasoning a cast iron pan).