Does anyone know how to diy it? There's basically nothing online, but I don't see what could make it prohibitive for the common man. I can't find a formula or anything. There's a few things I'd like to make, and I'd much prefer the dry cast look to the bubbly shit that results from wet concrete in molds
Old stone is handmade newer stone is concrete
>handmade
I mean they've been using stone saws for centuries .. what does handmade mean in that context?
Old stone is subtractive new stone is additive
It means someone carved a stone block with chisels, stupid.
Yeah man, no. Cast stone is as old as the Romans.
You are extremely ignorant. Basically everything made in the last 200 years has been cast in molds.
>Additive
...
you want to form stones?
are you a planet?
It's prohibitive for the common man due to the engineering genius it takes to make it not fall down compared to nailing tubafors which can be done by mexicans.
Sounds like you cant to check out this Technical Manual from the Cast Stone institute:
https://www.caststone.org/technical/CSI_Technical_Manual.pdf
This PowerPoint shows the basics on concrete design with a Standard mixture:
https://www.nrc.gov/docs/ML1215/ML12153A400.pdf
Using a larger proportion of fine sane will make a smoother finished face, but a less strong concrete mix more prone to failure.
From there you can cast the concrete in molds to the shape you desire. If what you want is a nice Polish, I suggest you try polishing Concrete blocks purchased from any old Box Store. Otherwise skim coat the cast stone and finish with a coat of concrete stain
I worked next door to and helped out a guy who did all kinds of cast stone and other similar decorative stuff, mostly for fireplace mantels but he did exterior stuff too and had been a professor teaching sculpture at a major university in Europe.
There nothing particularly difficult about the basic procedure but a LOT to know about mold making and casting/finishing if you want consistent results. The other big cost of doing it is the cost of tooling and space required to use and store it.
FWIW the bubble thing comes down to how you mix the material to avoid entraining air and knowing how to get what air does get in there out before the material sets up, typically some kind of mechanical vibration is involved. That said a lot of what that guy did with materials like plaster involved filling blemishes like that.
anon in on point, also for rougher surface treatments you can use an appropriate sized sand/gravel or other material like perlite in the surface layer and abrasive blast or pressure wash the cement binder away one it's out of the mold.
You can also use sand mixed with a water based glue to add surface details to mold surfaces to create natural looking variations and/or mold small details that show up in relief in the casting. Paper works too, tissue paper can give a shale- like look to flat pieces and you can mold details out of pulp the same way they make egg cartons and other dimensional shapes.
This company's overview pretty much lays it out and the advantages and disadvantages of wet vs dry casting...
https://www.haddonstone.com/en-us/our-materials-explained/
Thanks so much guys, this is a great place to start. Awesome. Can always count on PrepHole, only board where that's true
https://archive.org/details/practicalmasonry00purciala/page/12/mode/2up